Mercedes Sprinter Turbo – Limp Home – Diagnosis and Fault Finding

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Mercedes Sprinter Turbo – Limp Home (LHM) Diagnostics.

You will probably read a great deal on the internet regarding the issues surrounding your Sprinter lapsing into limp-home mode without showing any EML (Engine Management Warning Lamp).  I have also read these web entries with interest and have concluded that there is a lot of confusion around what exactly is going on so I have decided to add my own input so that hopefully you can sort out this irritating and troublesome issue.

The early Sprinters with vac controlled turbo actuators are quite basic in operation and there are only a few elements to the control loop.  These can all be checked out systematically and the faulty element identified and replaced/repaired.

Let me try and explain in basic terms how the turbo control system works so that you may get a better understanding of what is going on:

VNT Turbo and Vacuum Actuator (sometimes known as a VGT Turbo)

Sprinter Vacuum Boost Actuator

Sprinter Vacuum Boost Actuator

The turbo itself is a Garrett VNT variable vane turbo, the details of which you will find elsewhere on this site. ( http://www.mercedes.gen.in/WP35/diesel-mercedes-sprinter-turbo-rebuild/ ) It is controlled by a vacuum actuator that moves a set of mechanical vanes within the turbo to vary the turbo charge rate – there is no conventional dump valve on these turbos and many times you will wrongly read people refer to it as the ‘dump valve actuator’.   The charge actuator resides bolted to the turbo body on an extended bracket, its push rod connects to a small lever that enters into the turbo body casting, moving a small lever shaped rather like a dog-bone.  This lever engages in an annular ring that in turn interlaces with a set of similar levers attached to each variable vane. A single action of pushing or pulling the actuator rod moves all the vanes inside the turbo in unison, developing more or less turbo charge dependant on its position.  Inspect the external lever that the actuator push rod attaches to, ensure this moves smoothly as you accelerate / rev the engine.  Look for any misalignment of the lever throughout its stroke as it passes through the turbo body, as the bearing surfaces on this shaft can wear or oval allowing the internal lever to ride over the annular ring inside resultantly not moving any of the vanes.  A quick and dirty test to indicate any problems with the variable vanes is to remove the air box or air filter housing and listen as the engine is revved.  Once the engine is started, the vac actuator rod should move down slowly as vac builds, this in turn should apply force to the lever moving the vanes into a fully charged position.  As you rev the engine you should hear a very loud and strong tornado type howl from the air box, if you do not, and the actuator has moved pulling the lever downward there is a chance that the turbo itself is faulty.  Normal operation is as follows.  Stationary engine, rod fully extended, vanes in no charge position. Start engine, rod pulls lever downward slowly, vanes full charge position.  Rev engine, rod moves in and out during the rev cycle, vanes apply variable charge through rev cycle – Audible howl from air box.

Turbo Actuator Electric Vacuum Control Valve

Sprinter Boost Actuator Valve

Sprinter Boost Actuator Valve

If the vacuum actuator is not pulling down once the engine is started check for vac at the pipe, if vac is present, the actuator could be seized or faulty (internal diaphragm split) rectify this.  If you follow the vac pipe back from the turbo you will see that it goes to an actuator that is bracket mounted on the inner wing below the air box at the back of the off side headlamp (UK Vehicles)  This can be pulled upward off its bracket mounting rubber and moved to a better place for visual inspection.  This electrical valve actuator is popularly at fault with the Mercedes Sprinter model and your dealer will have sold hundreds of this item over time.  It has a single two wire electrical plug connected to it and three rubber pipes; in some cases its pipe locations are even marked: IN – OUT – VENT.  Check vac supply to this device observing and rectifying any split or leaking pipework.  Once good vacuum supply has been determined, with the ignition off (no power to the valve and no vacuum present) the route of vacuum should be blocked by the valve to the turbo actuator.  The turbo actuator supply pipe should be vented to atmosphere via the electric control valve to a small filter (looks like in-line fuel filter) mounted above the engine and sitting by the side of the brake servo.

sprinter vacuum diagram

Turning on the ignition places a constant 12v to the electrical controlled vac actuator valve, (This voltage pulses during normal engine operation)  vac should now be routed from actuator valve inlet to the turbo actuator (outlet) and the vent should now be blocked.   Vacuum switching can be verified by using  a hand vac pump (Mytivac or similar) Simply sucking on the pipes will not prove anything, as there is an internally sprung pressure control diaphragm inside the electronic valve so that operation will not occur until sufficient vac is present –  the only thing you will achieve by sucking with your mouth – is a red face!  An old Mercedes engineer once shared that there are two versions of the electric vacuum valve available, one with a blue cap and the other with a black cap, only the matching type should be used as a replacement.  I cannot verify this information as I have only ever seen the black cap type, but best practice would suggest replacing the unit only with the correct version to be 100% on the safe side.

Relevant Service Manual Extract View Here

ECU Control

The ECU control loop circuit is quite simple for turbo actuation.  The electric vac valve is controlled by simply switching the 12v supply on and off by the ECU, this is called PWM or Pulse Width Modulation – it’s easy to test this control voltage is present with a volt meter at the valve electrical plug/connector with ignition on.  If no control voltage is present look for a break in the wiring from the valve to the ECU.  Trace back the wires to the ECU connector and prove continuity exists from the ECU connector to the valve.  Pin outs and wire colours are given in the included diagrams.  There has been commonly reported breaks in the valve supply wiring as it is routed in front of the intercooler behind the grille and also in the area of the near side headlamp where the loom kinks back into the engine bay around the radiator. The wire colours to look for here are white and blue (on my model) but please check the included diagram/chart for correct model notation.

Relevant Service Manual Extract View Here – Wiring Identification at ECU – Turbo Boost

ECU General

Remove the ECU from its slide tray under the passenger dash area beneath the glove box area.  It is quite common for the bulkhead grommet to displace where the main ECU loom is routed to the engine bay allowing water to enter and run down onto the ECU connectors.  Remove all the connector attachments to the ECU and check for pin corrosion, if this exists clean up both the pin and connectors as best you can.  Importantly – reseat the bulkhead grommet.

Charge Pressure Sensor / Intake Air Temperature Sensor

Sprinter Boost Pressure Sensor Location

Sprinter Boost Pressure Sensor Location

There are two sensors in the control loop, a pressure sensor and an air temperature sensor.  They are identified as one having three or sometimes four wires (commonly three) this is the charge pressure sensor. The second is intake air temperature sensor having two wires.  They are both located in the upper section of the intercooler discharge hose, on the near side of the vehicle (UK versions) on the hard moulded plastic section of ductwork before the final supply hose to the inlet manifold, just to the side of the radiator.  The pressure sensor is attached to the housing with two small bolts.  The connections to this device are again simple to understand and test.  One of the three wires is ground, the second is 5v+ve supply and the other connection gives an approximate variable voltage output +0.2v to +5v referenced to ground dependant on charge pressure.  The other sensor (air temperature) is found slightly lower down the plastic section of pipework, this measures charge intake air temperature. This has a two wire connection that is connected across an internal thermistor bead that feeds back a change in resistance value relative to air temperature inside the inlet pipework, the two connected wires are fed through the bulkhead, directly back to the ECU along with those from the pressure sensor.  The temperature sensor should measure between 400 and 500 Kilo-Ohms out of circuit.  In the information given it is possible to plot the output from the charge pressure sensor to give an indication of charge pressure in the system, from this you can derive if it functioning correctly or if to suspect it as faulty.  If you need to measure what is going on in-circuit without disconnecting these components, take a number of drapery pins and push them through the insulation into the conductor cores of the required wires thus allowing you to connect a test meter and take measurements without the need to disconnect or cut any wires.

Relevant Service Manual Extract View Here – Sprinter Boost Pressure Sensor

You can disconnect any of these components without lighting the EML warning lamp as no indication of a fault is given by the removal of any of these components from circuit.  That is why the dreaded turbo limp home fault often occurs without any indication on the dashboard.

Rev Limiter Function

Normally Sprinter engine revs are ECU limited whilst stationary to around 3500 rpm. Depressing the clutch and then further releasing it should now allow revs to increase above this range to the rev limit. If there is a limp home fault, engine revs will not progress above 3000 rpm even when dipping/releasing the clutch when stationary. Once the fault is rectified the rev range and limiter function as described above will return to normal.  It is a good idea to check out both of the necessary brake and clutch pedal position switch sensors (on the pedal box above the clutch and brake) and where possible always get hold of a compatible diagnostic code reader as often faults are stored and not indicated with a EML lamp.

I hope this helps you to better understand the function of the turbo boost circuit on early model Mercedes Sprinters and that it assists you to fault find and rectify any problems you may have.

729 thoughts on “Mercedes Sprinter Turbo – Limp Home – Diagnosis and Fault Finding”

  1. Excellent article. Having problems with my MB Sprinter and I need to know how things work before starting trouble shooting. The engine will not rev and the turbo actuator does not move at all, so the boost valve or the clutch pedal may be where the problem is..

    Thanks again.

    Paul

    Reply

    1. Hi Paul,
      First off, pull off the vac hose to the turbo actuator with the engine running and see if there is any vac pulling. If not – next measure the voltage at the terminals of the boost valve, if absolutely nothing, check wiring in front of rad/intercooler. If volts exist, suspect boost valve fault. Good luck and do let me know how to get on.
      Regards
      Steve

      Reply

      1. Hi again Steve
        Success was rather short lived!
        Took it for a run and it seemed O.K. to start with but then it was back to normal….poor.
        Stopped and lifted the bonnet, The actuator seemed to be stuck. Moved it around a bit with pliers and then whoossh off we went again…like a rocket, the repair guy did say he thought the return spring on the actuator was a bit weak but that was not stopping it going to boost and as we know now, it was the vanes. Someone has suggested grease on the end of the rod/pin to help the action. I’ll use your link above and see if I can get a new actuator and hope that is the final bit to buy. Must admit when it did work it was great to drive and my heart lifted when I realised I could use the motorway again without fearing for my life!

        Almost there.
        Paul

      2. Hi Paul,
        If you undo the two 8mm nuts on the vac actuator (can be done in situ but its a fiddle) and then remove it wholesale. You can work on the shaft as it enters inside the diaphragm housing with WD40. Being able to move it through an extended range and wiggle it often frees off the arm. As long as the diaphragm holds vac all should be recoverable. (Squirt a small spritz inside through the spigot too – shh.. don’t tell the nay-sayers, they will say it will have an effect on the diaphragm material. In truth I don’t know if this achieves anything but I have never known one fail, its always caked in oil and is exposed to pretty extreme temperatures, make up your own mind on that one)
        Almost there.. (As one guy said on a Mercedes forum somewhere and it always sticks in my mind – ‘You’re on the pigs back now, you just have to ride it out..’)
        All the best
        Steve

      3. Hi again Steve,
        Well this could be the last lap. Took the van out this morning with the idea of risking it on the motorway. A mile down the road and its in limp mode again.
        The actuator lever is stuck again. I wondered if the vac pipe had a blockage in it as water may have got into the vacuum diaphragm as I pressure washed it before I took it apart.
        No, the pipe is clear so it can only be the actuator sticking in some way.
        So a quick mod, as I’m miles behind with work playing :=)) with this van.
        I rummage in the back of the van and I find a short bungee rope with wire hooks on the ends.
        So, one end on the turbo lever pin, a small detour round the clutch feed pipe ( to keep the line straight) and then it’s looped around and .clipped to the window wiper mounting bracket.
        We now set off and everything works! 50 mile round trip with motorways and some ‘A’ roads with very very steep hills lasting nearly a mile. No problem. I might even say a pleasure to drive. The mod will stay on until I catch up on work and then either a tidier mod or a new actuator.
        Well I got on this ‘pig ‘of a van and against what all people say ‘pigs can fly’
        My first van with a ‘turbo’ and it started as a real mystery but the mystery has all gone now and although I’m no expert, it all makes sense now and I’ve learned a lot thanks to your website and the people who bring you their problems..
        Many thanks Steve.

      4. Hi Paul,
        Interesting fix – but I think it pretty much stamps approval on that being the final issue. Lets hope so.
        All the best
        Regards Steve

    2. Hi again Steve,
      Well it’s been a year since I first posted and because I’ve been unable to find your site again and also being so busy, the old sprinter is still ‘chugging away. Motorways are really no go areas as the slightest incline brings me to less than 30mph and HGV’s fly past wondering what I’m doing.
      So A roads are my only choice at the moment.
      An update. I took your advise Steve and checked the vac to the turbo actuator and there is vac at the pipe from the solenoid pipe. When I connect up to the turbo the lever on the turbo moves down by about 20mm. Engine on tick over.
      Driving the van does produce a bit of power from time to time but it is far from ‘a train’ as others claim. I drove a similar sprinter up to Scotland last week and apart from a leaking water pump it went like a rocket.
      So I am going to replace the solenoid valve with another, take out and clean the ‘inter cooler’ and check for leaks in the pipework to the inlet manifold.
      Now I;m back on your excellent site I will check on others turbo problems and let you know if I make any progress.
      Regards Paul

      Reply

      1. Hi again Steve. Bit late but Happy New Year.

        Still struggling on with my Sprinter turbo.
        Not sure whether I should have done this but getting desperate now. I connected a large LED light across the wires to the actuator valve (in parallel).

        The LED is on all the time but when the turbo kicks in the LED is dim and when the turbo is ‘off’ the light is bright.
        I assume that the LED goes dim as the valve drains the power as it triggers the turbo. The turbo really makes the difference when the LED is dim i.e. runs well, but the turbo seems to be random on its working, its on and off state.

        Are there any sensors that I should check that are giving this random situation? As the light is on (bright or dim) all the time I guess the wiring to the valve is O.K. ( no breaks).and when the LED is dim the turbo is working and the van is fine.
        There seems to be no logic as to when the turbo works, under acceleration or driving almost on cruise the turbo works randomly.

        Not giving up yet, but close to it. I’m afraid with my problem and others with similar faults on these pages I think this will be my first and last Sprinter 🙂

        Regards and thanks
        Paul

      2. Hi Paul,
        What you have to remember is people only write more bad than good on anything ! Take a look at the Ford Transit forums with their EGR valve issues and Limp Home, Look at the VW forum and others and you will get the idea.. so everything is the same everywhere! If you want ultimate reliability maybe buy a Toyota Power Van, ironically it is a very little power-van, no performance, no load capacity, in my opinion no style (but who am I to judge). Now I have upset all Toyota owners, lets look at where you are.

        If you have a light that is dim when all is well across the coil and the coil is conducting – this then goes bright and the turbo fails to operate – doesn’t this indicate maybe the coil in the valve is intermittent? If the voltage source was disappearing, then the LED would extinguish all together – not go bright. Going bright seems to be an indication of no coil load. Is this a faulty valve I wonder?

        Do you see my logic?

        Never used an LED like this and not sure what effect it will have on the control circuit, but assuming it doesn’t, then the surely the above applies.

        What do you think?

        All the best
        Steve

      3. Hi Steve
        Yes I agree with your comments about Transits and Sprinters, few people go online to say how good their vans are, just the ones, like me, who have problems.

        Well I’m trying to see the logic, both you’re and mine. I swapped the valve for one that I was told to be good but still no turbo. The van has been working better today but still intermittent. It does seem to kick in the turbo more when it has warmed up a bit.

        I think I’m going to have to get someone to look at it and see what they think. I have a friend who runs a diesel repair garage. If I get somewhere with them I’ll let you know how I get on. Thanks for all your help and if I can get this Sprinter running as it should do I will sing its praises.

        Regards

        Paul

      4. Furthermore Paul,
        let us know each step of the way – so myself others may benefit from the information you come across getting this sorted.
        All the best
        Steve

      5. Hi again Steve.
        Update.
        Still having to use the van but dread going anywhere because of it’s lack of power. Had to climb a steep hill coming back from Wigan last week and thought I would never make it up this hill when all of a sudden WOW the power came in and off she went like a rocket!
        I guessed that meant that all was well with hoses and actuators it must be the boost valve or the sensors.
        So I ordered a new boost valve and fitted it but no luck. As bad as ever.
        So I tried the brake switch and messed with it in place, pulling the white pin out and pushing it in with my finger in and out with some WD40 sprayed on it.
        4500 revs at stand still. Never done that before. But that was short lived and as I drove away it was no different.
        So a new switch has been ordered and when it is fitted I will let you know whether the problem has been solved. Fitting on Monday if it has arrived from the dealers.

        If the switch is the answer I will tell you how the LED light works when all is well, it may help others identify where the fault lies.
        One other thing Steve, how important to the triggering of the turbo is the clutch switch and can this be over ridden to eliminate that as the source of the fault?

        Thanks for all your help. Fingers crossed again.

      6. Hi again Steve.
        Forgot to add that as I was messing with the brake switch I noticed someone had placed a cable tie over the brake pedal top lever, where it actuates the brake light switch.

        This cable tie I presumed was put in place because the pedal was not pushing the switch pin in far enough to operate something. Turbo or brake light switch, who knows.

        I am hoping that this ‘repair’ could be to fix a faulty switch and that a new one may be the answer.

        Cheers
        Paul

      7. Hi Paul. Sounds like you have found it. The clutch switch has to work as designed too – for example if you take it off, the vehicle will no longer rev over 3200-3500. It needs to be in circuit and needs to be working. Sounds promising so far and a very common problem as the contact set used for ecu feedback are very delicate in comparison the ones used to put the brake lights on – even though they are in the same switch case moulding.
        All the best
        Steve

      8. Hi Steve
        Well the new brake switch is on but still no power. Had to come back on the motorway tonight and could only do 25mph climbing the hill on the slip road to get on. It was frightening to say the least. Can’t go on like this.
        The power still seems to be intermittent. I can be driving along with little response from the throttle and then the turbo will kick in and a bit more power is available but it will still not rev above 2000-2300 revs.
        I can turn at traffic lights and the turbo works for a second and the van is lively but it does not last and again it will not rev.
        That time, a couple of days ago, when the engine revved at over 4000 it seemed like the brake switch would sort it but unfortunately no.
        Rapidly loosing faith in the van. New turbo cartridge, new boost valve, new brake switch, and I can understand the logic in the working of them with the ecu but there’s still an intermittent fault somewhere.

        What about the clutch switch? Did you say in other posts that this switch limits the revs?
        Had a look at the wiring down by the intercooler but it all looks good and the ecu unit and wiring appears dry so, still wondering what it can be. The LED light still shows bright until the turbo works and then it goes dim and the roar from the turbo can be heard and the power is there but no high revs. Thinking of fitting a camera to show the turbo working as the engine is driven, and seeing the movement with speed and power.
        Thanks again

        Paul

      9. Hi Paul,
        Not sure how you feel about this but I think its time to either invest in a compatible code reader or entrust it to someone with access to one! Parts darts gets expensive as you have found. You need to know exactly what the faults are and to be able to access live data and see exactly what is going on. The clutch switch works in conjunction with the brake switch to tell the ECU what is going on. If faulty it will have an effect on the maximum revs and limp home.
        Lets stop guessing and start being smart with our diagnostics, you have pretty much done all you can by swap outs, it could even be fuel delivery pressure but you cant see that one!
        All the best
        Steve

    3. Hi Steve
      Latest and hopefully final update.

      Long story but it may help others like me struggling to sort out their problems.

      I took your advice and eventually took the Sprinter to my mates who run a diesel repair business in the village.
      Left it with them but mentioned that I only wanted them to spend a couple of hours on it before it went to the scrap yard.
      I had got the new boost valve and foot brake switch from them so they knew they had been replaced. I had also taken the wiring from the front of the radiator and stripped all the covers off so that they could see if that was damaged.
      After altering a few earth points on the harness the cables now run over the top of the radiator in flexible conduit so that we can see if there are any problems. The boost valve is now fastened to a bracket over the top of the air filter housing along with the ball reservoir.
      Everything is now easy to see and work on :-))

      So my mates at the repair shop said it’s ‘the turbo’. No fault codes.
      They had checked back pressure in the exhaust system and no faults there, but no turbo pressure. They knew I would investigate further myself so they let me take over and strip down the turbo, again!
      Before I did that and on the way home I stopped at another mechanic I know and said ‘drive it and let me know’ After a short drive ‘it’s the turbo’

      So I stripped it down. As I checked the vane control ring it seemed to stick in one or two points. Not all the time but every 5 or 6 turns of the ring.
      So I stripped down the VG block and there I noticed that some of the vanes had the very slightest damage on their trailing edges, where I presume the old spindle, as it wobbled around, caught the ends of the vanes.
      15 minutes later and very careful use of a file and emery cloth and the vanes seem to run more smoothly in the block.
      Everything was carefully re-assembled and checked for vane movement and I think ‘hey presto’ it may be working.
      So a few morals of this story for me. If I repair a turbo check,check,check for every possible damage deep in the guts of the unit. If I had done that 18 months ago I would have saved a lot of heart ache.
      I’m not bothered about the new bits I bought that were not really needed. I’m hoping that the van runs for a few more years without any major problems but if not then I know it’s not the boost valve or foot switch.
      So now the final questions Steve.
      I’ve taken it for a short run down the country road. Need to put some diesel in it before I go far.
      Acceleration is not brilliant until I get to about 10 mph and then I get a surge of power, and then as I gain speed a second surge develops and the van really starts to fly. Is this as it should be?
      Secondly I was going to risk going on the motorway to test it out and give it a good run to ‘clear it out’. The back doors are covered in a black smoke film from the exhaust over the last year! Despite constant cleaning.
      Should I add anything to the fuel for this run as I have seen in advice for other posts?
      Many thanks for your help, advice and time Steve and please keep up the good work.
      Singing the vans praises may come in a week or two!

      Paul

      Reply

      1. Hi Paul,
        Its up to you but you can adjust the lower point at which useful boost starts, this is done by shortening/lengthening the adjuster on the boost actuator arm. See my post – ‘new turbo, still no boost’. You may decide its not worth it as to have useable boost without tripping over or under boost conditions is a good place to be. If you do decide to tinker then only turn the adjuster on the rod one turn at a time and remember where you are so it can be put back.
        A good result all round really, just think what you have learned. It seems on par with most local mechanics!

        You can fit a new vane block if you wished. http://www.ebay.co.uk/itm/Turbo-Turbocharger-VNT-Nozzle-Ring-Honda-Accord-Civic-2-2-i-CTDi-/330895490321?pt=LH_DefaultDomain_3&fits=Model%3ASprinter&hash=item4d0ae87d11

        I would not bother adding anything to the fuel, spatter on the back doors is normal until the soot is cleared. (its a pig to remove, as you have or will discover washing wont shift it! T-Cut or car polish is about the best at the job)

        All the best
        Steve

      2. Hi Steve
        I may have added my latest update in the wrong place. It’s now at the top of my list, by the first post.
        Sorry.
        Paul

  2. Hi Steve,

    Just wanted to thank you for your excellent article re the LHM on my 2004 Sprinter. After replacing a split charge air hose I still had the loss of power and low revs etc. and spent many hours looking for the fault and was about to take it to my local auto shop and spend hundreds of dollars, before I read your article. It was easy to follow and very logical, I followed all the steps and found the Vacuum Boost Actuator was stuck. I sprayed the turbo linkage end with CRC226 (WD40)etc. a penetrating fluid and after much wiggling the lever became unstuck. Its now back to normal and been ok for quite a few trips.
    You have saved me a lot of money, if you come to Brisbane Australia, the drinks are on me. Thank you very much,
    Have a nice Christmas and Happy New Year.
    Cheers,
    Howard Bond

    Reply

    1. Hi Howard,
      Thanks for kind words, I am glad it helped you out with the LHM issue and you managed to fix it yourself!
      I may one day even take you up on the offer of that beer !
      All the best
      Steve

      Reply

      1. Hi Steve,

        I have a 312d based motorhome which is suffering from lack of power issue. We only recentlyacquired it and the service history is patchy. I’am following this thread with much interest and will take a look at the turbo actuator. Is there a a cheapo diagnostic code reader that works with these vehicles ?

        Thanks
        Paul

      2. Hi Paul,
        The best low to mid end solution you can get for your money is the Autel unit. There are a couple of Autel Maxidaiag readers available, the first is for European vehicles only then there is one for all makes. Either will do the job well and also cover transmission and ABS/SRS which is handy! $250 to $300 USD which returns quite quickly if you intend to maintain the vehicle yourself. My opinion – Don’t waste any money on a cheapo $50 unit as they will misread and mislead you as they are not 100 per cent compatible with MB models.
        All the best
        Steve

      3. Hi Steve,

        I’ve written to Autel UK requesting that they recommend a model that is known to work with a Pre 2000 Sprinter. Their reply was that because of my sprinter being old ( 903) chassis only their high end code reader ( £1250 ) would work.

        I’ve written to another reputable company in Wales and they said that they are sorry but they cannot help with any suggestions because of the age of the Sprinter.

        I’ve been searching all over the internet over the last week to find a autel scanner costing around the £200 – £300 mark but more importantly is likely to work with early sprinter and have met a dead end.

        I’d appreciate it very much if you could give me the model number of the Autel scanner.

        Thanks
        Paul

      4. Hi Paul,
        Here is the unit I use, it so far has been compatible with all Sprinters I have used it on. (CDI Turbo Engines) http://www.auteltech.com/Professional%20Scan%20Tools/365.jhtml The covered models in the Sprinter range of the Maxidaiag MD702 are shown on the opening static picture of the video on this page, http://www.mercedes.gen.in/WP35/sprinter-t1n-faulty-injector-electrical-connector-intermittent-limp-home/ this video is taken of the unit I use. If you can satisfy yourself that your model is covered (it should be) then this is the tool for you!
        All the best
        Steve

      5. Hi Steve,

        I purchased the MD702 unit and to read the codes. Unfortunately it was unsuccessful in communicating with the ECU and/or retrieving the codes.

        The good thing was I was able to return the unit and get a full refund.

        My only option seems to be to take it to Mercedes dealer to get the codes read as none of the independents have the diagnostic reader for a “sprinter of that age” 🙂 .

        Thanks for all your advice.

      6. Hi Paul,
        That is very interesting, and fortunate that you got a refund. I wonder if the very early models pre-99 were OBD1 and later changed to OBD2 compliance? When you get to the dealer just ask this if you can as it may be possible in the future to get an older OBD1 reader and mate it to the 14 pin connector. – just a thought.
        Many thanks for the info and do report back from time to time.
        All the best
        Steve

      7. Hi Steve,

        Since my last comment re diagnostic scanner I’ve discovered that the EGR valve is faulty ( hole in the diaphragm) and soot in that area. Have ordered a new one.

        I have also discovered a vaccum pipe going nowhere. Do all 312d Sprinters have Vaccum reservoirs ? Could it be that the vaccum pipe mentioned above was intented to be connected to a reservoir?

        Thought I’d check and rectify as many issues as possible before taking it to MB diagnostics to get the codes read ( and hopefully cleared ).

        Many Thanks
        Paul

      8. Hi Paul,
        Sounds like you are getting some where!

        From the brake servo vac connection should be a T piece (Actually more like a Y) that is a take off that supplies both the turbo actuator and heater flap/vent controls in the cab. The upper direction of the pipe feeds the cab/under-dash and following the pipe downward should take you to the Turbo actuator under the air box. There should also be a vac reserve sphere here to, often green sometimes black. About the size of a tennis ball with one pipe connection. If you have a floating pipe it could be the vent pipe that goes from the actuator to an area just inside the curve of the bulkhead as it slopes towards the gearbox. (LHS as you are looking into the engine bay UK versions) Usually this terminates in a connection to a small filter unit about the size of a cotton bobbin fastened to the upper bulkhead.

        Hopefully this will help you trace where that pipe should be.

        All the best
        Steve

      9. Hi Steve,

        Since my last comment I’ve changed the EGR valve. Also followed ( more like tried to follow) vaccum pipes. There is a pipe that goes from EGR valve to some sort of valve ( could it be some sort of actuator?) . From there there are two pipes disappear into the tangle of wires (possibly to do with heater flap control?). When I start the engine ( with the new egr valve) the egr valve diaphragm pulses for a couple of times and then stays open). This makes me think the vaccum actuator maybe working.

        There is small vaccum pipe that goes from the turbo actuator into the inlet part of the turbo. There are no other connections to the actuator. The rod does not appear to move and could be stuck. Could a vaccum pump be used to check this?

        As far as I could seethere are no vaccum related items / piping under the airbox. I do not know where they have all disappeared :). A lot of vaccum pipes seem to go into an area under the windscreen. As this is a Hymer motorhome maybe the layout of the piping is different.

        I’ve got a well known publisher’s workshop manual but it is pretty thin on details for a novice. It probably would be just the job if I am into rebuilding engines and gearboxes but I am no where near that skill level :(.

        Just wondered if you have any suggestions on where/how to get a detailed workshop manual for a 312d.

        Thanks for all your help and advice
        Paul

      10. Hi Paul,
        Have a look here: http://www.boards.ie/vbulletin/showthread.php?t=2056973504 post #20 specifically. It looks as if the actuator could be the place to start now. There is a chance the layout of the Hymer is different than the stock vehicle as it maybe has a different front (body) section. If you pull the pipe off the actuator you should be able to move the actuator with firm finger pressure, if not then investigate further.

        Most of the MB manuals other than the Haynes are written from extracts from the manufacturers documentation and as such don’t get any more ‘understandable’ than the one you have. Follow the links menu on the top of this page (far right) and click on the Sprinter Information Resource link – Download the 2003 Sprinter Manuals .zip file. This covers models from year 2000 and should have many common sections and chapters.

        If you have no luck with the actuator then take a few digital pictures and email them over of the vac piping and where they go and we will see if we can investigate further. steve@mercedes.gen.in Did I mention about checking the brake light switch above the pedal? Not even sure if it plays a part in the turbo control of the early engine configuration but I am assuming yes. If it is a switch with more than two wires exiting from it, the answer is it probably is included in the control circuit, so for what it costs change it. (V. Common problem indeed, the ecu thinks the brake is on and holds off the turbo) Its a twin switch contact affair and even though the brake lamps are working the secondary contact in the switch could have collapsed.

        All the best
        Steve

  3. Hi Steve, I have a 2004 sprinter 616cdi ,295,000km and it’s had an issue for many months now which is very frustrating, my friend works for Mercedes as a van and truck tech and cannot solve the issue. So here goes it makes a noise like pinking but it isnt, it had 5 new injectors 7weeks ago it can make the noise from cold but sometimes it doesnt, it’s had a new fuel line the one that comes from the centre of the fuel filter and goes to the lift pump(front top of engine) cos leaking sorted now. It had a new boost transducer 5 weeks ago but didn’t sort the problem the truck goes into limp home under heavy load normally 2000revs ish. It’s had a new boost pressure sensor didn’t sort problem. I’m at my wits end, next is new turbo which I’m ready to do but will be really peeved if it doesn’t sort the issue, also it lack power below 2k and chucks out a lot of black smoke. Hope you can help, also are you based in the uk? Could I come to you as I transport cars and I’m all over the uk

    Reply

    1. Hi Nick,

      That’s quite a rare beast you have there! What you describe are classic EGR valve symptoms, but I am unsure if that model has EGR fitted. I am sure your Tech guy will have the info if he hasn’t checked this already.

      I wonder if you have read any codes using Star? I assume there is no EDC lamp on the dash.

      In addition to the bits and pieces to check listed in the main post, the noise could be related to a timing issue and if no codes I would swap out the knock sensor at the back of the head/block, (again not sure if this model will have this sensor not sure what year it was introduced) this detects the pre detonation noise and adjusts the CDI injector timing to compensate – could be that. I would possibly have expected a light and a code to be thrown though, but who knows.

      It may be worth looking at the intercooler (inside it) and looking to see if its restricted or blocked or as I have found on some high milers half-full of oil, especially if its had had a turbo blow in its lifetime! Its quite an easy task to take this off if you don’t have AC, so wont take you much time to test/look. I would only suspect this if the problem is there all the time and not intermittent.

      Black smoke means too much fuel or not enough air – also pointing to an EGR valve issue that when faulty causes smoke, poor performance and pinging noises (if you have one fitted!).

      Its worth pulling the ECU from under the dash and removing the connectors, some times the bulkhead grommet allows water in to run down the loom into the connectors causing corrosion/bad connections. Remove the loom plugs and have a look at the pins of the ECU and clean off any corrosion/green that you find.

      Your tech should be able to test the boost pressure by measuring the voltage on the boost pressure sensor (pins pushed into the wires) or read the pressure directly from a OBD scanner/STAR reader and so prove that the Turbo is OK and producing boost in the allowable range. Double check the turbo pipework/hoses and look for leaks – especially in the pipes that join the intercooler. Oily mess deposits around hose clips or joints usually indicate boost leaks. Make sure the intercooler hasn’t taken a stone hit and is leaking, again some dark oil staining will usually indicate a problem. Inspect the inlet manifold and its seals/gaskets, especially the plastic blanking plate/end cover at the back (bulkhead end on 4 cyl model, though I think yours is a 5 cyl) that often pushes its O ring out if the van has ever backfired.

      Try those few things these don’t entail much cost and if the fault persists rely on your guy with the code reader !

      Let me know how you get on.
      All the best
      Steve

      Reply

  4. Hi Steve
    Had a new turbo today which has sorted the black smoke problem out and low boost pressure, goes like a train, the 616 is the inline 5cyl which doesn’t have an egr, the detonation/pinking noise well I think it is det/pink noise is still there, so questions again…..the knock sensor(Mercs call it a camshaft position sensor) can you tell me more about the symptoms or this playing up and also the air temp sensor. There are no codes,star machine was plugged in today and just had the same codes as before low boost pressure which is now sorted and glow plugs of which two are not working and the tech disconnected the plug a little while ago as the two had gone down but they wouldn’t come out of the head and the tech didn’t want to risk them breaking off in the head so disconnected the plug,apparently in the uk the temp doesn’t go low enough for them to come into play.

    Reply

    1. Hi Nick,
      Thanks for the update. Glad the smoke/power issue has gone – at least some compensation for the expenditure on the new turbo, well worth It!
      Before trying anything else, run your tank as low as you dare, fill half up with BP Ultimate Diesel and then add a Cetane booster (Like an octane booster for petrol but for diesel) This one is a good one. Don’t bother with the Redex branded booster as it only specs a Max Cetane boost of 2, the Millers specs a 5. Let it run for a few miles and see if that cures the pinking noise. Some diesels seem to favour better performance diesel fuel than the ‘Supermarket Stuff’ If its no different then begin to look at the components that control the injection timing. You have new/recon injectors so they are out. Cam sensor and Crank Position Sensor are the only other links in the chain. Almost every van I have seen over 10 years old has no working glow plugs! They all start and run fine – ask any courier company with the older model sprinters. So discount this and not worth the risk of replacing/fixing. The intake air temperature sensor is in the intake tract and would flag a code if faulty. I bet you are running your 616 on low quality diesel. (just a guess – don’t shoot me down!) Try the Cetane booster and monitor the effect. You are getting there !!
      All the best
      Steve

      Reply

      1. Hi Steve again……

        I run the sprinter on shell diesel only and once a week run it on the nitro diesel, I’ve used millers octane booster before and can’t say it has made a difference, the noise it makes is difficult to describe and mainly does it on what I would term neutral throttle, In between acceleration and not. It’s so frustrating, it’s driving my (friend) Merc tech mad

      2. Hi Steve,
        Just for your knowledge and folk on here the noise which had been there for sometime gradually got worse on Thursday morning and she finally let go(no.5 piston ). I’m a little disappointed with only 300k on the clock but when I bought the truck it had 120k on it and who knows the history of that mileage and 9years. Anyhow what are the best tips for running in the new 5cyl lump which is new from Mercs?

      3. Oh dear!
        That is sad news. So what I guess you were hearing as ‘pinking’ was in fact the little-end of No.5 beginning to oval. That’s how it is some times sadly, we would all do with X-ray eyes!

        With regard to running in, just use common sense, don’t labour or over-rev it. The extract from the Mercedes Handbook shows the following:
        …………………………………..
        Running-in

        It is of decisive importance for the operating life, reliability and economy of the vehicle that the engine is not subjected to its full rated load during the running-in period.

        Up to 1,500 km

        Run the vehicle in carefully. Drive at varying road and engine speeds.

        Avoid heavy loads (driving at full throttle) and high engine speeds. Do not exceed 3/ 4 of the maximum speed available for each gear.

        Change gear in good time.

        Do not change down a gear manually in order to brake.

        Avoid depressing the accelerator pedal beyond the pressure point on vehicles with an automatic transmission (kickdown) and only engage gear 4, 3, 2 or 1 while driving slowly.
        After 1,500 km

        Gradually bring the vehicle up to full road and engine speeds.

        These instructions must also be observed if you have the engine, the transmission or the rear axle differential of your vehicle replaced.
        ……………………………………………..

        Good luck with it Nick its a shame it ended this way but at least you will know its history from here forward! Drop the oil and change the filter after 3k if you want to really do the job right as it will rid it of all the running-in debris.

        All the best
        Steve

      4. Hi Steve.
        I also have the Sprinter 616cdi here in New Zealand. This one had the problem of cutting out altogether at random times while driving. I don’t believe I have done anything to fix this issue however from the beginning of winter, or the colder days this problem has vanished 100 percent. Its as if the air intake temperature had something to do with it…..Anyway, I was looking forward to how it would react in the summer months but I now have a bigger problem. I stalled truck in 1st gear, it took about 20 sec to restart then was sluggish. Then just as I was realising this it gave the death rattle! Could it have jumped a tooth on timing chain? Am I hearing valves hitting pistons? We are about to pull engine out and start stripping. Will look for damages then asses what to do from there but am thinking another engine. Is there a good workshop manual around which will guide me regards engine work? Thanks. Dan.

      5. Hi Dan,
        Good luck with the rebuild, the best resource for Manuals and info will be here Sounds like cam chain issues as you report. Be interesting to hear what is the result of your investigations. I hope the links to the info covers all you need – if not with a little thought most of the info can be applied to your model as a great deal of the ancillaries and parts configurations are common between models.
        All the best
        Steve

  5. Hi I have a Mercedes 413 cdi diesel turbo sprinter leisure seeker winniebago in the last few months we have been having trouble maintaining any speed up hills seems like we lose power all though on the flat it seems ok most of the time any suggestions please

    Reply

    1. Hi there,
      My suggestion would be to check all hose connections on the induction side, post turbo. It sounds if you may have a boost leak under heavy load. Check all the hose clips to and from the intercooler, if you see oil staining/film around the joint there is a good chance you have found the source of the leak. Check also the large induction hose that goes to the inlet manifold, this splits underneath, along its length where it escapes casual inspection by eye. Take the hose off and look for faults by flexing the hose between your fingers. I will place my money on this being the problem. Good luck.
      Regards
      Steve

      Reply

  6. Hi steve can you help!
    I have a 56 plate sprinter 311 I was driving it home on Saturday I pulled over and turned it off. I then started it up and pulled off I started to get to about 85 and then it started to slow down and I found not get anymore than 65/70 and Struggled in sixth gear,and now it feels like the abs is kicking in!? Can you help please

    Reply

    1. Hi Duncan,
      It would be good to check induction hoses for leaks, especially at the joins/hose clips to the intercooler. Usually oil staining indicates a boost leak at the joints. Make sure the vac hose to the turbo actuator is not split and is a good fit on the spigot. Check out the other fault finding tips in the post and let me know how you get on.
      All the best
      Steve

      Reply

      1. Thanks steve
        I’ve only just got to read this. I’ve been into my local garage today they plug it in and it worked fine for about 30 miles. I’ve gone back to the garage again this evening they plug it in and they give me a fault code of 2511 which I don’t know what it is,so they cleared the fault again but now it’s gone back into Limp mode again and now the engine management light has come on with the esp light, can you help me on this one thank you

      3. Hi Duncan,
        I would guess there lies your problem: Code 2511 (001) Component Y27 (Exhaust gas recirculation positioner) does not function properly. Positioner signal fault.
        Here is your first port of call. It may be you can get away with cleaning it but I am unsure if there was a recall 06,07,08 with this component as it was modified because of reported failures (This may have been on the Vito but remains sketchy in my memory) Either way this is the best place to start. Its a rotary device driven by a stepper motor and gets all gummed up with soot. Worth a try.
        All the best
        Steve

  7. Hi Steve, can you help please?
    I have a 2005 311cdi which has an intermittent LHM fault and similar to Duncan’s it feels as if the brakes are on.. It can be fine for a 1000 miles or do it 3 times in less than 5. Sometimes the turbo kicks back in by itself after as little as 5 secs, other times it needs the ignition switching off and restarting.

    I found that the jubillee clip on the charge air pipe was a bit loose where it connects to the sensor housing (very oily) which didn’t cure the problem. Since then I have changed the both the boost valve and sensor but still no permanent fix.

    As a european courier it doesn’t take long to do a 1000 miles. thing I have noticed is that when in LHM if I press the clutch in the engine revs let the clutch back up and its stuck at 3000.

    Any advice that you could give would be very much appreciated,
    regards
    Mike

    Reply

    1. Hi Mike,
      If you have checked most of things mentioned in the blog post then it may be a fuel pressure or fuel pressure sensor problem. There is a pressure transducer that lives in the end of the HP fuel delivery rail and it is quite common for the two ‘O’ ring seals to perish and cause some issues, although usually its more to do with starting than low boost. However the most sensible thing to do would be to get an independant garage to read the vehicle and list you the fault codes – go straight in and sort the defined issues instead of the ‘scatter gun’ approach that often runs away with money at a great rate of knots.
      There is one other thing that I have had cause similar problems – on the right hand side of the engine under the bonnet, beneath the inlet manifold you will see the low pressure fuel delivery sensor in a T piece connector. This has a connector that faces down toward the road and often becomes loose or a poor connection, should this electrical connector become disconnected or corroded, the ECU gets a ‘high fuel delivery pressure’ signal and cuts back the vehicle into LHM. I cannot say that this will be the cause but on more than one occasion now this has been the problem and is well worth the short time to check before moving on.
      You may wish to have a look at a fellow posters information here: http://sprinter-source.com/forum/showthread.php?t=7173 there is a few pointers and suggestions for you to try without me retyping. I really think the best advice would be to get the fault codes read and move forward from there.

      I hope you get sorted, do let me know what you find.
      All the best
      Steve

      Reply

  8. Hi Steve, many thanks for your reply, I’ve been a reader of the posts on sprinter source as well as other similar forums and found them very useful in the past. Your write up on the subject I found to be the most informative.

    I understand what you mean about the scatter gun but seems to be the approached used by both Mercedes and the local garage. My faith in the so called professionals is somewhat lacking because despite their “Diagnostics” into the the fuel problems which kept tripping the EDC system as well as poor running its had a new fuel pressure regulator, hp pump, fuel filters, all 4 injectors reconditioned (they were over fueling but it didn’t cure the fault at the time) hours of pondering and avoiding phone calls. It was finally fixed on 1 occasion by me replacing the return valve on top of the fuel filter (thanks sprinter source) the other 2 by the garage repairing a damaged wire in the engine loom. Over £2000 spent and fixed with a bit of black plastic and some wire.

    This intermittent LHM started occurring before the above so feel that it not fuel related. The ecu has logged the following codes amongst others over the last 3 visits.

    P1470 Charge pressure low
    P1470 Charge pressure neg Control, Charge pressure low
    P1470 Charge pressure neg control, charge pressure high
    P0105 B5/1 Charge pressure volts to high
    This what led me to changing the parts that i have,
    I will check out the sensor you suggest as that is 1 thing that hasn’t been replaced.

    Could you tell me the purpose of the clutch switch as detailed in your write up when the van is moving? it will rev freely with clutch pressed in when in LHM mode which you say won’t happen with the van stationary.

    The other thing i hope you could tell me is what is the sensor or component that is in the crank case vent hose where it joints the turbo air inlet? the wiring for this also runs through the main loom where there has been so much trouble.

    Thanks again for your time in replying to my post.
    regards
    Mike

    Reply

    1. Hi Mike,
      It does seem that the boost pressure is up and down, or at least the reported signal to the ECU is, that P1470 indicates that. Give the pressure sensor a try, I have indicated the position of this on the T1N Sprinter in the write up somewhere and am pretty sure you will find it in a similar location. I think often even the ‘so called experts’ are baffled by what they see on the code reader, the truth is they are and have been trained to use that alone, all the old fashioned fault finding – understanding the principals of what is happening – now plays little part in modern diagnostics. Indeed often a problem with one element will cause an indication on the code reader that is more of a result of the problem than the cause! I have always found it better to try and understand the issues along side what the ‘magic device’ tells you, this way you get a better focus on the problems at hand. (My two pence worth anyway)

      There are two switches at play on the pedal box, the first is the clutch switch that stops the vehicle being over revved when stationary, this can be over ridden by the ‘up down method’ to test and see if the engine will rev over 3000, in other words see if it is in a fault condition without showing an EDC light etc. The other is an area that may be worth a look is the brake light switch. This is a dual switch and lies not surprisingly above the brake pedal. This not only provides the signal to the rear stop lamps but there is a second set of contacts that tell the ECU that the vehicle is being retarded and signals not to apply boost. You can test this out on a vehicle that is working correctly, drive in 3rd gear at a medium pace, then cover the brake with your LEFT foot and while applying gentle pressure to the pedal, try and accelerate with your right foot on the throttle – it will not allow you to and the engine stumbles! I suppose this is a ‘fail safe’ that if in an emergency braking condition you stamp the boards, catching the throttle with your size 12s would not make any difference to the level of stopping distance. I am pretty sure that it is just a safety feature. The dual switch body is a known trouble spot, just because the brake lights work, does not indicate that the secondary part of the switch is functioning correctly. Could be worth a look – its known but rare that this gives problems – but who knows!

      The ‘T Piece’ device with a pair of wires to it you can see in the crank case breather hose, where it joins the turbo inlet pipe (from the air box) is in fact a small heater ! This operates in extreme low temperatures to stop water vapour or emulsion from freezing in the pipe blocking the crank case breather so I doubt that this will be the source of the problem even though its supply is in the suspect loom section, unless of course it is shorting out and causing fuses to blow etc.

      I hope that helps you out Mike, keep in touch and let me know how you get on. I am about to go and change a disc and pad set on a LWB 313 this morning and then onward to a front spring and leg on a Clio, so a busy day ahead – hope the weather stays good.

      All the best
      Steve

      Reply

  9. Hi,I have a sprinter motorhome based on a sprinter 416, 2001.Heres the problem,took the van for a mot last year,passed no problem,but seemed to be very under powered on the way back home ,30 mph roads,thought nothing of it.Went away on holiday to holland,very flat roads,seemed under powered on the way there.but coming back home up the A14 ,read long hills there was no power at all.The van seemed okay before the mot, the only thing that I can think of is when the engineer asked me to rev the engine for the exhaust gases to be analised I reved it alittle harder than I would normally do.It was only for asecond or two.Would this cause the engine to effectivly go into limp mode,nothing showing on the dash;Many thanks.

    Reply

    1. Hi Russ,
      The MOT blast should not really have caused any issues, its more likely if it is connected to this event that a Turbo boost hose is leaking or is split allowing boost to escape. On this age of vehicle not always does an EDC lamp illuminate. Check all the hoses and connections post turbo, as I have stated before look for black oil staining as this is usually a dead give away to the location of a boost leak (especially on the intercooler entrance and exit pipes). Check the vac connections are sound and that the turbo actuator moves on a rev. (No movement = no boost being called for) The manifold/boost pressure sensor may be faulty / misreading, its a cheap component in the big scheme of things and is well worth a swap. Really all the fault codes will be stored, if you can get them read and then just rectify ‘exactly’ what is indicated as the problem and see how you go. Often £40 spent at an independent for a code read at this stage will save you a great deal of time and money in the long run.
      Good luck, do let me know how you get on.
      All the best
      Steve

      Reply

  10. Hi,steve ,just need to add that my sprinter has the sprint shift gear box,thanks for the easy to follow logical approach to the problems listed.Russ

    Reply

    1. Hi steve ,thanks for the reply have been busy with work lately but we plan to go away in a week or two so I thought I had better look at the van again.took It up the motorway today but there does not seem to be any boost from the turbo.At home I have taken the air box off to check for any thing obvious.There is a tiny air leak from somewhere,but the van has always had this slight leaking sound after turning the engine off, it lasts about 1 min then stops.I have traced it to the turbo boost actuator valve.Heres the brain stormer……if I disconnect the tube from the turbo boost actuator to the vacuum actuator,and place my finger on the connection under the turbo boost actuator ,where I had pulled the tube from, the air leak stops and I feel a suction on my finger.If I start the van with the pipe still off the vacuum actuator not alot seems to happen but If I keep the pipe off and then put my finger back on the bottom of the turbo actuator the air intake sounds like a turnado, if I pull my finger off again the rushing sound goes again.So is the boost actuator at fault or is the vacuum actuator leaking air to the turbo actuator?The connection pipe between the two seems okay.Many thanks.Russ

      Reply

      1. Hi steve, I have got my information mixed up!I have double checked today…..the air leaking sound is coming from the boost actuator.Its coming from the ventoutlet for about 1 min after the engine is turned off,the noise stops when I put my finger over the vent tube.When the engine is stopped,there is suction on this pipe ,WHEN THE ENGINE IS RUNNING THERE IS ALSO SUCTION ON THIS PIPE!.If I start the engine with all pipes connected except the vent pipe(under the boost actuator), the vacuum actuator pulls the turbo rod down hill as it should,if I rev the engine the rod does move slightly up and down,but the vent tube connection under the actuator is sucking in air ,quite strongly,I thought that once the engine is running there should be no pressure on the atmos- vent?Whilst the engine is running I got my son to rev it alittle whilst I messed about under the bonnet,what I found is that if I block the atmos-vent with my finger and revved the engine the vacuum boost arm woiuld not move but the air flow sounded like a tornado,does this mean that the boost actuator is stuck and not changing the pressure in the actuator from atmos-vent to boost valve? I have taken the boost valve off the van and pushed its rod back into its body(as if it were in vacuum state) then put my finger on the inlet tube under the unit,the rod moved back only alittle and stopped in position ,keeping avacuum until I moved my finger off the inlet tube,so I guess that its okay.Many thanks ,Russ

      2. Hi Russ,
        If you have removed the air box you will see a small plastic ball about the size of a cricket ball. This is the vacuum reserve – make sure this is not the source of the leak, if so replace – this is providing the vac you can hear once the engine is off. From what you explain it seems more likely the actuator valve is faulty under the air box and not functioning as it should, especially as you say it makes a loud sucking sound. The ‘atmos’ is a discharge vent (breathe out) that vents stored vacuum in the turbo actuator line via the valve allowing it to extend the rod again when needed. Constant vac here would most probably indicate a leak internal to the valve – at least something is not as it should be with the actuator valve!
        All the best
        Steve

      3. Thanks Steve,I have ordered a new boost actuator,or as my merc dealer calls it, a transducer…should be able to fit it early next week,will let you know how things progress,heres to fingers crossed ! P.S I have also ordered a pressure sensor so will fit this at the same time.Many thanks Russ

      4. Hi Steve,just a quick up date on the van,I replaced the boost sensor,actuator valve and the vacuum reserve( still has the same air leak sound but I needed to put the van back together for a short break in snowdonia last week.No problems the van pulled like a train,and strangely,no puffs of smoke that I used to get when accelerating,very odd.I just would like to say thanks for the advice and keep up the great work .Many thanks .Russ

      5. Fantastic news!! Glad it worked out. It may be worth you checking the brake servo hard plastic hose line that runs from the servo to the vac pump on the front of the engine, these can wear through especially where they cross the top of the radiator. Small hole draw vac making a noise similar to what you hear. I would have expected if this was the case that the brake efficiency was down a little though (hard pedal).
        Keep in touch
        Steve

  11. This is brilliant thanks, I’ve just replaced the vacuum solenoid on my ’04 311cdi trying to cure a cutting out problem (accompanied by a loud knocking/rattle and clouds of smoke) codes were P1470 charge pressure negative control – charge pressure low alomg with P0201/2/3/4 high current common wire.

    It’s cured the cutting out and now just occasionally goes into limp so next job is to check-out the wiring to the vac’ solenoid.

    I found reference to a repair section of wiring on a parts list published on a Russian website (genuine mercedes part) but now can’t find my way back to it, looks like I’ll have to cut & splice?

    BTW, something is blocking me saving this site to favourites, nothing happens when I right-click.

    Thanks

    Max

    Reply

    1. Hi Max,
      Thanks for the good comments. Sounds like you are on top of it now.
      The wiring loom at the front is quite simple to splice into as there is only a couple of wires to trace back through, so I would go for that option. The Gen In site pages are deactivated against right click to make it a little less simple to copy photographs/content etc. I am sure the favourites – ‘add to list’ will still work if launched as part of your browser favourites function.
      Let me know how you get on with the Sprinter.
      All the best.
      Steve

      Reply

      1. Rather than splitting the existing harness (not a lot of room for red crimps & heat shrink), I’m looking into using OEM parts and do a proper job. The parts list is a little difficult to decipher but I think I can order a new plug & terminals for the solenoid end and terminals & plastic holders(?) for the ECU end (looks like the terminals &holders slide out of the multi pin plug at the ECU?). It’s going to be difficult to get the new wires through the bulkhead grommet, what do you reckon?

        Max

      2. Hi Max.
        I take it you have seen/measured a fault in the wiring continuity between the ECU and Solenoid? What I would consider doing is splicing in to the loom just on the engine side of the bulkhead grommet, where access is easy. If you cut here you can measure and prove all is well back to the ECU from this point, and run your cable to the solenoid easily within the engine bay. The problem area with the existing cable will most likely be where it hooks round the rad/intercooler, so splicing in here should be a good compromise. I would use solder and heat-shrink the joins, maybe even use self-amalgamating tape, like you say crimps are not the boys for this job! If you do need to get into the ECU area in the cab from the engine bay the best way to do this is puncture the grommet towards its middle near the central core of wires with a bradawl or terminal screwdriver, push your wires through a tightly made puncture hole and they will be almost self sealing through the grommet. You are correct in that the ECU plugs have a slide out connector inner within the latch assembly. Hope this helps.
        All the best
        Steve

      3. The boost control went ape again the other day after a heavy downpour so I think it must be moisture getting into the harness somewhere, once everything had dried out and I’d sprayed the harness & connectors with GT85 she’s fine again.

        I’ll give soldering a go, just need an assistant to hold the wires as I never seem to have enough hands [one for the iron – one for the solder etc :)] .

      4. Here we are again, right back at square 1

        I rewired the boost control valve weeks ago and things have been fine since then, until another really heavy downpour on Saturday and she’s back to cutting out again, EDC warning light is on constantly and power is down.

        I’ve done all the usual checks, cleaned & GT85’d every terminal block I can find to no effect so will have a go tomorrow following your diagnostic guide above. Is there any particular point that is prone to water ingress I should concentrate on? (the ECU is fine, bone dry).

        On a slightly different topic, I cleaned & lubricated the brake bias valve linkage & actuator today but can’t figure out how it’s supposed to work, the short spring holds the actuator in the “closed” position, it appears to me that the linkage off the shocker mount tries to pull it even more “closed” , can you advise?

        Thanks yet again.

        Max

      5. Hi Max,
        You seem to have covered most everything. I take it you replaced the loom section by the passenger headlight as it rounds the intercooler? (this is where the loom rubs/fractures commonly) It is possible that it is unconnected to water ingress. A stab in the dark would be either Camshaft or Crank sensor – this may or may not be associated with poor starting. I have had similar issues with low pressure fuel delivery and a filter change has cured this. As always you are better to invest in a read of the fault codes and save all the guess work.

        The brake load sensing proportioning valve is in simple terms a sliding piston in a housing bolted to the chassis, this piston varies fluid passage ‘orifices’ dependant on its position – ie. how far the piston is allowed to extend under braking pressure. The arm and spring mechanism bares on the piston head to control the pressure required to force the piston out under braking and thus the amount of brake force applied to the rear wheels (by regulating brake fluid flow through the orifices) with regard to van loading. Allowed to extend outward, the braking force to the rear wheels is reduced to a minimum, fully retained inward the transmitted brake force will be at maximum. Have a read here: http://sprinter-source.com/forum/showthread.php?t=21459
        Hope this helps.
        Regards Steve

    2. Hi Steve, back again.

      She finally failed to start today after another heavy downpour (there’s a theme developing here), Snap-on code reader is comiing up with P1190 fuel pressure control valve open circuit.

      A few questions – is this the one under the vac’ pump on the front of the head and would partial failure (before todays complete fail) give me the 3000rpm limp home symptoms? It’s hard to tell the condition of the wiring but it certainly doesn’t look as bad as the boost control solenoid was prior to rewire, is this a known wiring fault?

      Thanks once again for all your help, keeping white van man moving, when we’ve both got more time I’d like to discuss tuning chips with you, specifically taking my 311 up to 130ish BHP.

      Cheers.

      Reply

      1. Forget the bit about it being under the vac pump, it’s on the back of the fuel rail isn’t it? Is there any way the valve can be tested or any checks I can do to the wiring ie testing for a voltage at the terminals before the valve is condemned?

        Thanks again.

      2. Did a bit of playing today while waiting for the new valve to arrive, I’ve got continuity from the red/white wire at the plug back to the ECU with a pretty low resistance as well and the black/white wire earths to the battery negative just fine. With my meter connected across the valve terminals I’m getting continuity and about 3.5 ohms resistance but that’s with the valve at rest, who knows what it’s like with fuel pressure acting against it?

        Max

      3. Hi Max,
        There are three pressure devices, one on the LP supply in a Tee on the fuel rail under the inlet manifold towards the front, another on the HP pump, rather like an elongated tower that mounts to the triangular shaped pump with the connector pointing to the inlet manifold side of the engine (Connector is a sod to get on off, but will just make it) finally the HP fuel rail pressure regulator valve, this is the one you are saying is on the fuel rail itself hidden in that small gap under the inlet manifold by the fuel filter canister.

        As all things seem to happen when its raining, just make sure there is no water running down the loom from the grommet in the bulkhead where the ECU lives by the bonnet release as it can wet the connectors on the ECU ports.

        Keep in touch and let me know progress as these things are rarely straightforward.
        All the best
        Steve

      4. The ECU was one of the 1st things I checked, all the terminals were bone dry so eliminated that. Got my new pressure control valve fitted it with new seals and… not a peep.

        funny thing is, as soon as I switch the ignition on the temperature gauge goes full scale so I suspect a short in the wiring some where, it would be too easy if somehow the red/white supply for the fuel valve had chafed into the temperature sender circuit, off to try and trace it now 🙁

      5. No joy yet, it’s now pitch black and freezing so try again tomorrow, one thought, should the engine start with the top off the inlet manifold or does that mess up some inlet air pressure sensor?

        Thanks

      6. Hi Max,
        Not the time of year for messing outside is it. Least the nights should start getting lighter now all be it slowly! I reckon it will at least start but don’t expect it to rev freely, it should idle at least of sorts.
        Regards and happy Christmas,
        Steve

      7. Max, the main problem area for loom faults is where it dips down from the head, under the inlet manifold down past the engine mount. This bunch gives by far the most issues, cut it open and inspect it. The temp sender, fuel filter water sensor, fuel pressure regulator, and fuel pump pressure sensor all run in the same part of the loom at the front of the engine. You can see where they split under the fuel filter and go to their respective positions.
        Regards
        Steve

      8. Thanks Steve, I’ll give that area some attention between rain showers, I’ll throw another fuel filter on it just in case although the one fitted is only around 5-6000 miles old.

        I spent half of yesterday looking for a valve that isn’t fitted on my van, the fuel shut-off under the vac pump isn’t there, no wiring for it from the ECU so that’s one problem I haven’t got? I’ve just worked out (I think) why there are 2 fuel pressure sensors, one on the front of the rail signals the control valve to open/close maintaing correct rail pressure and the one under the manifold signals insufficient pressure and shuts things down?

      9. Max, if you have a non start situation then it could also be either of the following: Camshaft sensor or wiring, crankshaft sensor or wiring, any of the injector connections or wiring. Any failures of the above will prevent the engine starting. Correct on the sensors, under the manifold is low pressure supply sensor/switch.
        Regards Steve

      10. One minor success today correcting damage I’d caused (deformed the terminals in the pressure control valve connector block forcing in my meter probes, the male-female terminals weren’t connecting), now when I crank the engine over I get an occasional stutter as though it’s going to start.

        The temperature gauge is still flickering around and managed to snap the terminals off the probe when disconnecting (will the engine run without a temp probe connection?) , battery now on charge and my finger tips are blue so try again tomorrow.

        A quick question, is there any way of confirming the various probes/sensors are functional without substitution ie by measuring resistance or confirming continuity across terminals otherwise I could potentially spend a fortune buying new components i don’t necessarily need?

        Thanks again

        Max

      11. Well the good news is she started today, don’t know if it’s anything to do with what I’ve done? The engine is knocking a bit & smoking under load and the throttle response doesn’t seem to bear any relation to what my right foot is doing but she runs (edc light still on all the time) so I can get her to the garage and have the codes read, I know one will be a temperature sensor fault!

      12. Got her to the garage today for a code read, I’ve still got P1190 control valve open circuit but I think that’s being caused by P0190 – Bank 4-6 rail pressure sensor signal voltage too high.

        Gonna look for a short between the fuel pressure sensor circuit and the engine temperature circuit that’s possibly what’s causing the fuelling problem and causing my temp gauge to flicker between zero and full scale, fingers crossed it’s not the sensor, that’ll be another £200!

      13. Glad you at least got it to a garage, and it ran of a sorts. It seems there are still some electrical gremlins to sort out. I too have been working over Xmas and its not pleasant outside. I did a timing belt on a Crafter CR35 2.5TDI and a full service – was dresses up like an Eskimo!
        Let me know how you get on.
        PS. I don’t have any comparison information for metered readings of what is good or bad regarding sensors so cant really help there, sorry.

      14. Well Steve, I’d love to be able to say it was dodgy wiring but no, the fault was with the fuel pressure sensor, new one fitted and she’s running A1, one thing I’m dubious of though is the sealing washer/O ring, the old sensor didn’t have one, it was sealed in with clear fish tank sealant and the new one came with a choice of steel crush washers, I had to use both to get a seal as the sensor bottomed out on the threads before either singularly got a grip, my local VAG dealer will have the correct seal tomorrow.

        Next job – remove the thermostat housing to change the temperature probe I snapped, can’t get a grip to pull it out.

        One more question – what to do about duff glow plugs, do I just pull a relay/fuse and forget? The garage who do my code reading have given me dire warnings about killing batteries/starter motors.

        Thanks again

        Max

      15. Result!
        Pleased that its sorted Max.
        I have never known a thermostat sensor come out yet ! if you manage it you deserve a prize. I always fit a new Febi stat housing complete with sensor and new O ring (All in the kit) for about £35.00 from GT Auto-factors. Its a tight fit to remove once the bolts are removed, made a great deal easier if you remove the oil filter bowl, just cover the open filter with a rag or stretch a rubber glove over it to stop crud falling in. Don’t pinch the wiring loom by the fuel filter when you reassemble.

        If you look at the glow control module, under the battery tray area you will be able to identify a thick supply wire going to the unit, right above to the ESPAR auxiliary heater, remove this and tape it up. Forget it, never fitted glow plugs in the UK and the fleet I service has not a single vehicle running with glows without an issue. You invite more trouble than enough trying to remove them and if stuck will cost you a head job if they break off. If you remove the control module plug you will flag a communications fault with the ECU so just remove the battery supply for the glow plug power.

        Have fun Steve

      16. Here’s a new one Steve, in my ownership (around 40k miles) the van has always ticked over at 750-800rpm, today it’s gone up to 1000rpm, is this like a petrol engine and I’m looking for an air leak on the inlet side somewhere?

        Cheers

        Max

      17. Hi Max,
        Nope, nothing like a petrol, take the turbo hose off and it will still idle at the norm! More likely to be throttle potentiometer (pedal assembly) or water/coolant temperature sensor fault (engine thinks it needs cold state enrichment and idle-up) The ECU sets idle speed, so it can only be an external control signal that is influencing the change.

        MY 2011 ish and a rise in idle could be the DPF doing its ‘cycle’ – if so idle will return to normal once regenerated.

        All the best
        Steve

      18. That’ll be the broken temperture probe, I haven’t got round to replacing it yet, strange that it’s taken 6 weeks to notice, and it’s back down to normal again today?

        Thanks .

  12. Hi Steve
    Very interesting information here.
    I currently have a 3.0 v6 vito 2007 in at the moment with this fault.
    The turbo is the one with electric actuator. Which moves freely and I can activate it with the Diagnostic tool.

    It has faulted the air flow meter (But its fine)

    The boost air temp sensor was faulty and always read 80c its been replaced
    The MAP sensor works correctly but live data shows the boost pressure at 0.8 bar all the time.

    I even plugged another MAP sensor in and pressurised and vaccumed it but the live data remained the same at 0.8 bar.

    I’ve checked the wiring back to the ECU from the MAP sensor.

    Any ideas?

    Thanks
    Ian

    Reply

    1. Hi Ian,
      I am thinking that the 0.8bar live data you are reading may be the default value plopped in by the ECU when it failsafes due to another control/sensor input error. You would kind of expect appx 2.5v as an ECU default value (0.8bar, 15 psi-ish) mid scale of a 5 volts sensor range. As a rough guide you should see appx the following back to the ECU actually on the wires from the MAP sensor (Turbo boostpipe pressure) and at least see its value varing upward in voltage as boost is applied – even if you have to manually move the VVT turbo actuator lever with engine reving :

      29.01psi 4.90V
      28.70psi 4.84V
      27.70psi 4.67V
      26.70psi 4.50V
      25.70psi 4.33V
      23.70psi 3.99V
      22.70psi 3.82V
      20.70psi 3.47V
      18.70psi 3.13V
      16.70psi 2.79V
      14.70psi 2.45V (normal air pressure – engine not running)

      If you use some pins into the insulation of the MAP wiring you should be able to prove the sensor with a test meter and see what you are getting. Of course the default condition may be caused/triggered by another issue but at least its a start. The same can be said for any of the other sensors, you need to test what is happening at the sensor and not always rely on the result as seen and read from the ECU via livedata, it will mostly put its own default figures in under some conditions! Do you have a EDC light up on the console? It may be worth having a look at the inlet air temp sensor pre turbo and see what that is giving as this is all rolled in the calculation along with the MAP etc.

      A real off the wall idea here – is the EGR stuck open? Allowing all or most of the boost to escape atmosphere, the rotating type of EGR valve can get gummed up and in one case I have seen the shaft break, so even though the rotation is taking place visibly from the outside the inside is stationary – becuause the shaft is bust. There was a recall 2008 for the EGR and MB replaced a number of units in some model ranges due to mechanical defects. May be worth ringing the dealer and seeing if the mod was done, it will show on the reg with MB as it it was an official ‘FREE’ recall (like the spare wheel carrier mechanism breaking off!!- another recall of the period)

      You have a bit to go on there and please do report back. I have found on so many occasions that the codes thrown and readings taken are often as a result of and not always the root cause of an ECU limp home issue. Just out of curiosity what are you reading/clearing codes with this may or may not apply to you but worth the read – http://www.benzworld.org/forums/v-class/1686500-vito-120cdi-no-power-fault-code.html

      All the best Steve

      Reply

  13. Hi Steve.
    I have a 2002 Mercedes Sprinter 616cdi. It has the 2.7, 5 cyl turbo diesel eng. Firstly I would like to say that these small trucks are fantastic. My issue is that it will cut out completely on an irregular basis. By cutting out I mean you can be travelling quite happy at 100k’s/hr then all of a sudden engine stops sudden and all dash lights come on. Ususally within 10 seconds of coasting I can restart but this exercise isn’t much fun when fully laden and towing a trailer……also can happen unlaiden. I have had a scanner on it and the fault code that rings a bell P1187 Rail pressure monitoring deviation. I have been advised that a fault such as this can have the ECU shut down immediately. Could this be right? And if so or otherwise where do you think my problem lies? Have just changed fuel filter. Any help would be much appreciated.

    Thanks
    Dan.

    Reply

    1. Hi Dan,
      There is a chance that the fuel rail pressure sensor is giving problems. If its not the sensor itself then there is a couple of very cheap O ring seals on this sensor (sealing it to the rail) that perish and start to leak past giving pressure reading problems. Usually this is diagnosed as poor or none starting but I suppose could not be unheard of as a cause of intermittent stalling due to incorrect fuel pressure feedback. Its also worth looking at the wiring on the loom on the right hand side of the engine as if looking into the bonnet as it stretches from the block to the bulkhead it is known to be troublesome with chafing or broken wires.
      First port of call is to change the O rings, only a few pence and well worth a try!
      All the best
      Steve

      Reply

  14. Hi i have a vito 108 cdi its also throwing a code p1470 as well as 1188,1636,1622
    I have replaced the lift pump the high pressure pump fuel pressure regulator and today the boost actuator valve still can’t seem to fix it
    as soon as the key goes on the ddc light comes on and goes into limp mode
    i am running out of money fast any idea what else i can do to fix this
    could it possibly be the Map sensor as its loving a code even before i start it and when i clear it it comes back straight away?

    Reply

    1. Hi there, sometimes when using a code reader other than the MBStar it throws some generic codes, often for faults that do not in reality exist! Just to be aware as I am unsure what you are using to read/clear codes. I think the issue is without doubt electrical and not in any way mechanical or directly related to the turbo actuator or its control transducer. You will have to check the location out, but there is a supply fuel pressure switch located before the low pressure pump (its like a brass T piece in the fuel line with a single 2 prong electrical connector) I have known this be faulty or the connector bad and does immediately set the ECU to Limp Home. Check it out although its exact location is unknown by me on your model. Remove the electrical connectors from the ECU and inspect the connection pins for corrosion, rectify if an issue. I fear P0107 would have been expected if there was a possible MAP issue but these are a common fault component and if possible worth substitution to be sure. I am assuming the vehicle idles and starts OK – but if not check injector connectors/wiring and also cam position sensor plug and wiring although neither seems indicated as an issue by the absence of their respective trouble codes.
      Please let me know what you find.
      All the best Steve

      Reply

      1. Hi thank you for that. I am using a G scan which isn’t the best for Mercedes but that’s all I have! The sensor is on the fuel pump which got replaced when the pump did and they even have me another new pump with another new sensor to try but same problem. I think it’s faulty ecu at this stage as the second I turn on the key even without starting it it logs the codes. It starts and runs great so the rest of the system is fine. As I unplug each sensor one at a time it logs an entirely different code related to that sensor so so far everything else seems ok. The other thing I noticed is my scan tool doesn’t show the rail pressure and shows coolant temp to be -237 deg now that could be just having issues communicating with the scan tool but I am pretty sure it use to read everything ok. Which also points to a faulty ecu. Also has anyone changed an ecu before as my numbers don’t quite match up to anyone else’s will it still work?

      2. Hi John,
        Maybe you are correct, its a pity you could not test/substitute with another known good ECU before shelling out the money. If you cannot get fixed up locally Ebay could be your best bet for a unit with matching part numbers, there are a few engine/spec variants and you should get one of the same part code/year of manufacture to be sure. There is a chance that there could be a loom issue and I would try and prove at least a selection of sensor connections from the ECU plugs to the device connector with a test meter before investing in a replacement ECU (Circa another £100+) If one wire is short, grounded or otherwise down to engine neg/ground untold faults could result due to the internal regulated voltage outputs from the ECU being effected.
        Good luck and I hope you get it sorted – it seems sadly its not going to be an easy fix. Let me know how you get on. All the best Steve.

      3. HI yeah i took it to a Mercedes dealership yesterday they put it on the genuine scan tool and looks like either its damaged wiring to the valve on the pump or faulty ecu. One of the guys who works there said he has seen where the engine mount has been removed to change the pump and the wire for the valve be squashed when the mount is put back in place because it runs up close to it at the rear of the engine so today I’m going to pull that all apart check the wiring with a multimeter and then failing that its a bad ecu!
        I have been searching on Ebay for a kit but mine has a different number to all others i seem to be looking at. Apparently mine has a 110 hours power engine in it and is manual where usually they are only in an Auto so if i get a kit with different numbers it will work but i could end up with only 90 horses! saying that its going to go a lot better then limp mode!!
        thanks so far for all your help

  15. Love this article. Would you please tell me if the boost actuator valve is the same thing as boost pressure solenoid? Thanks in advance for your time…

    Reply

    1. Hi there,
      Indeed you are correct, the terminology may be slightly different but the device is the same. Glad you found the article of use.
      All the best
      Steve

      Reply

  16. Hi Steve, I am going to tackle your fault guide to see what I can find wrong with my Vito, 1999 108cdi manual. I bought it and have done precious little driving as its been in the workshop seemingly forever with EDC and Glow Plug Light on.

    A brief rundown, 1st workshop fitted new glow plugs and 2nd hand glow plug relay, fault returned after about 2 weeks, I went to a shop that has experience with Vitos and they gave up after 6 weeks and returned the car to me, no charge.

    2nd shop a diesel specialist (and I saw a few Vito’s on the floor so I was quietly confident), replaced the Injectors ($2500.00) problem returned 2 weeks later, said the Computer was faulty and required replacing.

    I decide to go to Mercedes, First attempt played with it for 2 weeks and disconnected the vacuum line to the vent and headlight control saying there was a vacuum leak robbing vacuum pressure on the turbo line and causing fault $700.00 returned car problem returned after 2 weeks. I returned to Mercedes and they found a faulty capacitor in the computer quoted $3000.00 for computer plus $1200.00 labour, I had a 2nd hand computer tested and cloned by a computer specialist and Mercedes fitted it $1200.00, returned the car two weeks later fault returned. Given this history where would you start looking, I have had enough with incompetence being charged at $180.00 and hour. It in to me for over $4700.00 in parts and labour and still wont drive more than one tank of gas before I’m back in the workshop.
    Graeme Power

    Reply

    1. Hi there Graeme,
      Wow! what an ordeal… I would imagine if the glow plug lamp is on all the time (or does this only light in conjunction with the EDC lamp when the fault occurs?) I will assume that the fault is there from turning on the ignition and both the EDC and glow light are illuminated. If this is the case it is my view that you have a wiring issue. If you were to say that the ECU had not been replaced then that would have been my knee-jerk suggestion as problems are not uncommon here. However I think it is safe to assume that the fault would not be present in two ECUs ! So my suggestion still stands – Wiring/cable fault.
      First I would investigate the wiring around the glow plug relay as this is known to be troublesome, especially with body bonded earths and supplies. Check the condition and connectivity within the connectors of the red and black wires respectively.(include the thinner control wires in your inspection too)
      It is unusual in itself for Glow faults to cause an EDC limp home condition and this is why I err toward a wiring issue, perhaps a sensor is grounded to chassis or shorted to another one somewhere on the engine loom.
      You must check the wiring by the engine mounts, John reported that if your van has had the fuel pump replaced or work been done in that area is has been known to trap/damage a wire to the boost actuator where the mount has been removed/replaced. Well worth a look!
      It may be that the EDC limp home scenario and the Glow plug lamp are not related and this must not be discounted, although the wiring needs careful inspection. Depending on your viewpoint (and wallet) you may wish to buy a good code reader that will give you insight into what is going on – This is really an essential tool as it will give you pointers as to where to look for problems. Obviously this will involve some investment but if you choose the Autel 702 Elite you can maybe look toward recovering some of your investment by offering to read other European cars in the covered range, I suppose these would be labelled in some cases as ‘specialist’ in the US:

      Covered Range Autel MD702 Elite

      Benz, Smart, Sprinter, Maybach, BMW, Mini, VW, Seat, Skoda, Audi, Opel, Land Rover, Jaguar, Volvo, Porsche, SAAB, EU Ford, Vauxhall.

      This tool will be your ‘eyes’ in finding any problems and although may not point directly to the fault it could help lead you to a solution. Often without this tool frustration and uncontrolled money disposal result very quickly – probably enough of that pain has already been experienced I would imagine. My money is on a wiring fault between ECU and one or more sensors in the engine bay (this could be intermittent. The repairing garage/shops will have reset the ECU and cleared codes before you had the vehicle back,the fault would then occur again after a short period of driving. Once triggered some levels of faults cause EDC Limp home operation and can only be reset by using a ‘code reader’ and any fault logged would remain until cleared) and perhaps an unrelated ground wire/corrosion problem with the wiring to the glow relay.
      Let me know what you find.
      All the best
      Steve

      Reply

      1. I still have a sense of humour about this, the Mercedes Workshop seems to think I have a bottomless wallet for their technicians? to learn fault finding. When I bought the van it had several glow plugs broken off in the head. I had that repaired to find the glow plug light on and I then had the glow plug relay replaced and that gave me about two months of trouble free motoring. Then the EDC started to come on and you have seen the chronology of that till I replaced the ECU and now they both come on together, my question is…
        I turn on the ignition and the lights come on to tell me all is good, I start the car and all the lights go out for about three seconds and then the EDC and Glow Light Come on and stay on, Does this mean the computer reads a problem and reacts in that 3 seconds.
        What I am trying to accertain is. That three seconds that the lights are out for, is that the computer reacting to a newly found fault or is it just a process of starting. I want to know that so I can decide if the fault code clears on its own, that would be a big help if it did as I could then look for the fault and know when I found it as the lights would simply not come on, I have driven Mercedes vans like this before that went into limp mode whilst driving but cleared on their own some 2ks later only to return the next day and clear themselves again intermittently. I would like this fault to be one of those so I dont need Mercedes to clear the codes for me.
        Graeme

      2. PS, I forgot to ask, is this the Autel I need to be looking at eBay item 291011629694, I think I will require adaptors to fit the round plug on mine though. I found a bit of oil in the egr Valve area is that something to worry about.
        Graeme

      3. Hi Graeme,
        The Autel is the one on ebay. Since there were a couple of CAN protocols used on the Vito (ISO 9141 and KWP) I hold my hands up to knowing which you may have, although the Autel covers both I would just drop Autel an email and ask their compatibility advice, they are a good bunch and don’t take too long to reply to an enquiry. There are many custom ‘adapters’ (like this: 221081471709) available cheaply on ebay that convert the newer connector to either of the two older rounder types. Its just a matter of selecting what you need.
        I hear what you say about the EDC lamp, sadly also there is a group of faults that cause limp home and no EDC lamp lit, so there are many combinations and severity. Unless you know what you are dealing with its foolhardy to assume the level of fault you are dealing with. I think the delay of lamps illuminating you see on starting is the normal cycle of check lamps and doubt that the fault has gone away temporarily. It probably needs clearing down and re-reading to start any diagnostics. As I have advised many times, the reported faults on the code reader often indicate the result of a problem and not necessarily the cause, especially with component/wiring failure – but its the best place to start.

        Hope that is some help.
        Steve

  17. Hi Steve,
    Since my last post ( March 1st) I have resorted to replacing the complete engine loom. It only had 2 test runs out and all seems ok so far.

    However the van has developed a starting problem when the engine is hot. I hoped that this was also being caused by a damaged wire in the loom.

    Alas no, stopped in the Esso on the way back this afternoon and it wouldn’t go. It goes to fire but cant quite get there and shakes and bangs as though its trying to run on 2 cylinders.

    Leave it to cool for a few minutes and it starts fine. Could this be the cam sensor as there seems to be no problem with fuel pressure or edc light?

    I know this is off the true subject of your thread but any advice would be very much appreciated

    Best regards
    Mike

    Reply

      1. Hey guys I got my vito sorted out ended up being the ecu. Must have damaged a chip inside it . I got one from the uk numbers didn’t match up totally the last 4 digets were different to what I had. I got the ecu and key with immobilizer plugged it all in and no more fault codes or limp mode driven it about 100 kms without any issue so it’s good to know the ecu kits are interchangeable

    2. Mike, this is most probably due to failure of the small O rings that live on the fuel rail pressure sensor. The fact it is worse at starting when warm/hot is a common tell tale. Also you must check and swap out the cam position sensor on the top of the rocker as this some times has heat related faults purely because of the fact it spends its life running from hot to cold. My money is on the O rings!! (Pop into your local dealer and get a couple, they will be used to selling them !)
      All the best
      Steve

      Reply

      1. Hi steve
        I will check those as well, can they leak then without tripping the EDC light?
        Regards
        Mike

  18. Hi Steve
    Spoke to Merc, they told me that sensor has no o ring but pressure regulator has. Problem is that they can only be changed on engines up to no 508. mine is 510 so it means a new regulator.

    Could it therefore mean that this is not the problem as they changed the design to stop it happening?

    regards
    Mike

    Reply

    1. Hi Mike, the regulator seals on as you identified correctly as the regulator (I called sensor) will give problems and also the sensor itself can realise issues without flagging any EDC or fault codes ! Its a common problem and I would make a few enquiries as to what you are being told about the two version as I thought they both have a plunger and piston arrangement that carries O rings. Perhaps the dealer actually meant that the later part was not available with separate O rings as spare parts. Worth enquiring anyway.
      What did you find with the leak down test on the injectors, I am assuming this is all OK?
      Don’t forget the cam sensor in the back of the rocker cover.
      All the best
      Steve

      Reply

      1. Hi Steve

        I should have explained it better, with the new regulator the O rings are not available as a separate item apparently (from 2 dealers) How much of this is down to an improvement or just a sales ploy who knows. The one fitted was replaced by merc about 2 years ago trying to fix a problem (Which it didn’t). I have the original so could swap them over as there is no obvious damage to the o rings.

        The leak off test I did as per the Sprinter Source web site using 3/8″ tubing. I got about 1/2″ in each which equates to 1ml, well below the max allowable.

        I did however ever read later on an extract of a merc manual that says to disconnect the pressure regulator as well as the cam sensor.

        As for the cam sensor I whipped that out and cooled it down with a wet rag as quick as I could, then popped it back in and the van restarted.

        However It might well have do so any way. I tried the reverse and stuck the sensor in some hot water but van still started.

        Maybe its ok or I else I didn’t get it hot enough, so I will try again.

        Will let you know if the other regulator makes any difference.

        Thanks again for your time

        best regards
        Mike

  19. Hi there
    I have just bought a 56 reg 311 sprinter ex tesco it is restricted to 60mph , how can I get this derestricted is this ecu or will it be a fuse some where
    Or even get it put to 70mph
    Will this be a main dealer job or can most garages do it

    Reply

    1. Hi Iain,
      The restriction is set in a file in the ECU and configured when the vehicle is ordered. A dealer level Star Diagnostics computer can delete it for you but you would have to check the price at the Main Dealer, alternatively drop this guy an email at Williams Diesels (Kent) if you are located in that area I am sure they can help you out. dean@williamsdiesels.com they used to be very active on the forums and are very capable of doing the job. If they cant help I am sure they could recommend someone in your area that could.
      Hope that helps a little.
      All the best Steve

      Reply

  20. Hi Steve,

    Spoke to you about our 616cdi which had a new engine in which i have to say is cracking but still have a small issue, which was there prior to the engine going bang. On the motorway it’s more noticably at the limited speed of 56mph,every now and then it will do something which can only be described as like when a generator is running out of fuel it will hunt and then it disappears.
    There is know pattern to it and would say it’s done it for a good year or so. After the new engine was run in 40k on it I have put a tuning box from TDI-tuning which is super, loads more tq and power but the issue is still there, it’s just be emphasised. Can you help,many thanks in advance.nickp

    Reply

    1. Hi Nick,
      I suppose when you changed the engine all the LP/HP fuel pumps were swapped over. This sounds as if there is a problem with air in the fuel, probably caused by one of the hard plastic clear pipes that connect the Low pressure pump to the HP pump feed. These have a black connector on the end that can benefit from a new O ring. Also the way the aux belt runs, really close to them slung under the HP pump it is possible if they are not retained properly that the belt could be slapping them occasionally and causing a small gulp. They should locate in some very poor plastic clips. It goes without saying that the obvious fuel filter leaks/pipework should be checked, the non return housing at the top and if you have a push in water in fuel detector in the base of the filter canister this is a known hot spot for drawing air if not fitted correctly. Another long shot would be to have a look above the tank and check the pipework especially on the fuel cooler (its a tightly wound coil of pipe say 3 inches diameter and about 8-9 long, I have had one of these leak and it did give the same issues you are getting.
      A few pointers there, but your main man MB technician should already be on top of these I guess so I doubt they are much help. Let me know.
      All the best
      Steve

      Reply

      1. hi there i have a problem with my automatic sprinter 56reg i was slowing down at a junction and i have knocked van into park from drive i turned it off then it wouldnt start again . the stick still goes park reverse etc but doesnt turn over to start , do you have any ideas what this could be

      2. Hi Iain,
        In reply to your email:
        When you say will not turn over do mean the starter does not spin at all, almost as if there is no electrical connection to the starter or does it click as if it s jammed. I will presume the former and assume that the shift selector switch maybe thinks its still in drive and of course this will inhibit the starter motor from operating. (normal safety device on an auto) I think there is a strong possibility of this.

        What does the selector indicator display on the dash? If it shows P or N and still does not start/turn over then there is a strong possibility that the gear control ECU is held in a fault condition (Is it the Sprintshift semi Auto or conventional Auto?) Any problem with the gearbox will hold off the engine from starting as a fail safe (MB Design). There is a chance that a clearing of the fault codes in the gear control module will rectify this although there could also be an internal issue causing the activation of the start inhibit failsafe. You really need to read the stored codes and unless you have a good code reader then a dealer or competent independent MB workshop is really your only source of help.

        I hope that has been of some use.
        Do please let me know how you get on.

        All the best Steve

  21. HI Steve

    i have a 311 cdi sprinter with the usual over boost problems, sometimes it slows a bit and then is ok again. most of the time it looses power and i need to turn the key on and off

    i have changed the boost valve, boost sensor and air charge sensor. i have also tried the sensor from a working sprinter

    does this suggest the turbo vanes are the problem and the turbo is over boosting ? it seems fine on full throttle and the problem happens on part throttle.

    i am not sure but i think i can hear a whoosh – i have taken off both pipes and checked them for leaks

    any suggestions greatly appreciated

    Mike.

    Reply

    1. Hi Mike,
      This could be a fuel supply problem. If the boost air intake pipework is all fine, and you can see the actuator moving on the turbo body and hear boost noise (hose work pressurising also) then there is a chance you could be looking in the wrong area. Fuel pressure is a common problem for throwing the ECU into limp home with EDC lamp. Start by changing the fuel filter, check the lines to and from the tank for poor connection (especially on the filter canister). Also check the clear plastic pipes to and from the HP / LP fuel pumps for air bubbles. If you see air bubbles travelling in these you have an issue with seals some where on the diesel supply circuit. There are a selection of pipework O rings that can be renewed to cure this if its an issue.
      Let me know how you get on.
      PS a read of the ECU would maybe tell you where the problem lies, get it read if you can it could save you a great deal of time.
      All the best
      Steve

      Reply

  22. Hi Steve
    I too have similar problems as above on my 311 2003 sprinter but have already fixed some of them. When i got the van it would run fine albeit for the black death which has been sorted rather cheaply but properly the van would run fine and happily go faster than i wanted. After fixing it felt like a bag of spanners so had it’s code read 3 things no3 injector fault on the firing cleared no more probs I had replaced this injector so an old code. Now the next one high pressure fuel pump shut off switch my high pressure pump has a switch on the main body of the pump is this it? the connector is not holding very well but is on or is the switch the one at the end of a fuel line off a t piece that goes to the low pressure and high pressure pump I have been searching for a pic of it but cant find one and my third fault was a turbo boost pressure fault I have checked the boost actuator valve and wiring it has voltage and varies as it should but van feels like it has no power. The boost actuator has vacuum pressure as i took off the pipe to the turbo off and put my finger over it it sucked not very hard but it sucked. Now my problem is the problem of no boost down to the high pressure problem or is the boost actuator or a faulty turbo. I popped into the nearest dealer to me to price the boost actuator and the pressure switch needles to say i was not overly impressed with how much so would rather replace one not both. I have no idea now which way to go.

    Reply

    1. Hi Rob,
      The T piece fuel sensor on the right side (when looking into the engine bay) of the block/cylinder head seam area is the supply fuel line low pressure sensor, the HP shut off sensor is the one on the HP body as you mentioned. You need to check the turbo actuator is moving freely and shifting the internal vanes of the turbo, rev the engine and watch the actuator rod, it should move – if not rectify this.
      If you rev the engine you should normally feel the intake induction hose go hard under pressure, this indicates crudely you have some boost. It is possible for lightly driven or vehicles that have spent a period of standing to have a seized turbo actuator rod, you need to check this out first.
      As you have some vacuum at the actuator feed pipe then its worth a shot to clarify the movement of the actuator and accordingly the small lever on the turbo body that moves the internal vanes for at least some movement before pointing the finger at anything else.
      Let me know how you get on.
      All the best
      Steve

      Reply

      1. Cheers Steve will look at the turbo now as the top hose does not go hard firms up a touch but not a lot will let you know what I find.

        Rob

      2. Hi Steve update decided to tackle the switch on the high pressure pump being loose removed rad and other bits managed to get it to stay on but to be sure used the old faithful cable tie trick to keep it on replaced everything. Now on to the turbo started van actuator rod moved down but seemed to stop 3/4 of the way down gave it a tap with the screwdriver i mean a tap no hammers used here it moved the rest of the way rev’d engine after employing reluctant wife to do revving it moved up down freely no stopping or jamming or sideways movement bingo (put it down to crud from the strip down), turned off replaced shield started up no warning lights then edc came on but van revved fine all the way to 4k and hose went a lot harder had a quick look round noticed low pressure switch cable connector reluctant to stay put cable tie trick again to hold in place restarted all fine no edc light now only got to road test now but looks like it’s fixed but will get it rescanned to make sure if i have anymore problems I know where to come Thank you for the help and pointing me the right way you are a god.

  23. HI Steve – your knowledge of sprinters is amazing !

    the van does not have an edc fault – i had a fuel pump fail some years again and i have seen that before

    i am wondering if i have a boost leak somewhere maybe in the intercooler – i have not been able to get someone to read the fault code because of the round connector.

    when you switch the van on the actuator moves and it moves when the revs are picked up also

    i suppose it is possible the vanes are worn / blocked up and the turbo actuator is a bit lazy

    i have been able to get the van to drive ok by blanking the atm port on the boost solenoid – this means there is vacum even when the ecu tries to stop any boost. It does not drive great but is ok cruising on the motorway

    i will try again to get the fault read

    Reply

    1. Hi Again Mike,
      Thanks for the accolade!
      If you have a boost leak the tell tale sign will be black oil staining, this will usually be where the hoses connect to the intercooler as they are hard to get at and frequently under tightened. Inspect the matrix of the intercooler for black oil patches from a hole or fracture caused by either accident or stone damage.
      The most common place for a split is in the big hose that finally joins the inlet manifold, this splits underneath where you cannot see it, so take off the hose and have a good look – sometimes the split only says hello when you flex the pipe or when its under a certain boost pressure, however I expect you should hear it wheezing.
      The turbo actuator rod end is connected to a small linkage that disappears into the turbo body this moves the vanes on the inside, you can see how on the photos of the turbo re-core/rebuild post on the site. I have seen the shaft wear the casting through which it passes, so as it moves, it not so much rotates but pushes up. This has the internal effect of disengaging the lobe that shifts the vane ring inside, so in truth the vanes never reach a full boost angle as the mechanics have worn. With the correct code reader you should be able to see the boost pressure fluctuating and make an assumption from actual fact and not guess work.
      You could pull the boost pressure sensor out and give it a good clean off with carb cleaner as these do get sooted/oiled up. Don’t scrub it, just spray and shake it dry as its quite fragile. You have possibly fixed the turbo boost to max with your mod, it should perform OK as a temporary fix – but boy, will it use some diesel!
      If you take look at the back of the plastic composite intake manifold (4cyl models), by the bulkhead, it has a removable panel about the size of the palm of your hand with a rubber O ring seal, if the van has backfired at some point (through using easystart or some other issue) this silicone seal can ooze or squidge out of its seat and you get a very well hidden boost leak from that point. Worth a look.
      A boost leak would normally cause the motor to smoke badly from the exhaust on acceleration as there is an air deficit, making for diesel rich combustion, Do you see this ? – if not we may be into a fuel delivery issue in preference to boost.
      Let me know how you get on.
      Steve

      Reply

      1. i tried several places today to get the fault code read – nobody has the old style connector to read the sprinter ecu 🙁

        i met a mechanic who has had a similar problem and fixed it by cleaning the turbo vanes

        there is a kit on ebay to clean it out

        has anyone tried it ?

      3. Hi Mike,
        No kit required for a vane strip and clean, just need a bit of time. Dismantle and rebuild covered in Sprinter Turbo rebuild post.
        Regards Steve

      4. HI Steve – i think i found the problem !!

        i cleaned up the pipes and intercooler with some brake cleaner and the oil residue came back

        today i removed the grill and bumper and the end of the intercooler has cracked !

        i hit a bird some time ago when driving and it must have cracked a little and now the crack is bad. I have taken the intercooler out and bonded it back together – if the repair does not last i have time to get a replacement.

        i will put it back together this afternoon and let you know if the problem is gone 🙂

      5. Fantastic news, that will be the fault without doubt. I bet it was all nice and black with oil staining ! I have myself seen road debris holes in the matrix made from stones and flints kicked up by forward traffic.
        Well done,
        best regards Steve

      6. a quick update

        the intercooler was repaired and unfortunately the repair did not last

        a new intercooler was fitted and it is drving a lot better ! I thought we are fixed

        however the ecu is dropping power for a few secs and then going back on again mostly in top geat

        so it looks like i had 2 problems

        my guess is the vanes in the turbo are moving too slowly so we see an overboost when they open – the problem seems to happen in the 2000 to 2300 rpm range at light / part throttle

      7. Mike do not discount a sticking or rough actuator that may be hesitating at a certain point on the turbo boost stroke. Worth investigating.
        Good so far. All the best Steve

      8. Thanks again for the advice. I guess sticky actuator could be the problem. I have checked it moves up and down and has no leaks.

        Does it have an internal spring etc

        I guess the only way to tell is to fit a new one ?

        Speak soon

      9. Good morning Mike, Weather is good so Ideal for messing!
        The actuator rod is sprung to be extended, so the vac pulls it in and shortens it. Its not a huge effort to remove it and have a play, a good WD40 blast and a bit of movement outside of its fixed geometry when fitted to the turbo, will usually clear any roughness on the shaft (that’s the main culprit) because its upside down on the vehicle you cant see easily if its rusted on the shaft just as it enters the diaphragm. You should be able to push/pull the rod and feel for yourself once its disconnected from the vane operating lever. When its off just check the small vane lever that goes through the casting on the turbo, if its worn and has over 1mm to 2mm of oval in the hole, then the lever inside can disengage from the vane operating ring at a pint in its travel, you can see how this works inside from the photos on the turbo rebuild. Worth a look at the shaft though.
        All the best
        Steve

      10. quick update – i had the heat shield off and took a look at the actuator

        nothing worn or stuck

        i pushed the arm from one to the other a few times and took it for a drive

        so far it seems to be ok !!!!!!!!!!!!!

        i will keep you posted if it plays up again

      11. just wanted to give you an update – i took the actuator rod off and pulled it about and it was all good for a few days then it was overboosting again

        i have fitted a small spring that pulls the actuator so it is extended ( i figured the actuator spring had gone soft over time )

        all seems good the turbo spools up really good and the van performance seems very crisp

        thanks again for all the advice (y)

  24. I have a 2008 Mercedes sprinter 209 it has engine eml light flashing and has no power fault code p2624 any ideas where to start

    Reply

    1. Hi there Joe,
      Fuel pressure related fault, I would replace the fuel filter first. If still no change look for problems in the wiring loom to the engine, especially look where the loom branches from the block to the inner engine bay, could be a short or problem of some sort in that region. You would be best to get a code read with some form of live-data display so you can be more specific where the fault lies as this code is a generic code and non specific for fuel pressure related problems. Filter swap first.

      All the best Steve

      Reply

      1. hi steve thanks for the quick response ok I have changed fuel filter and have bought a cheap scanner put a diagnostic on myself code p0101 and p1955 shall I snapshot live data for you to look at
        cheers joe

      2. Hi Joe
        It seems that the fuel pressure code has now gone? Maybe since the fuel filter change? Did you clear that code? I would imagine its more likely that the codes displayed on your reader are not manufacturer specific and may be misleading – the result being that they maybe difficult to rely on. I would check out all the turbo boost hose-work and look for splits and loose connections, these are usually indicated with oil staining and are pretty obvious, look especially on the intercooler and route to the manifold. A boost leak could cause the symptoms you have.
        A little confused,
        All the best
        Steve

  25. Hi Steve
    I have a 2002 Hymer motorhome (UK) based on a 316 cdi Sprinter (2.7l Sprintmatic). I have had this limp-home problem intermittently for a few years. On a recent trip I noticed that it seemed in part associated with the aircon: if the aircon was switched off then there seemed to be no problem, as soon as I switched the aircon on then I lost (turbo?) power – acceleration was poor and wouldn’t climb hills but I could get it above 60mph on the flat. I am not sure that the previous incidents were so linked and I can’t see any mechanical link although there may well be some electrical issue. We first noticed the issue in Portugal (hot). I have checked the various hoses as best I can given the motohome bodywork and could not find any obvious splits or leaks. The boost actuator moves when the engine is running. BTW we had a gearbox problem in Portugal which was fixed by a new pump and valves. A few months later we had the same gearbox issue so I had the van serviced by Pentagon who said there were no fault codes flagged either for the gearbox or the limp home problem. We are due to go to Spain in a month or so and I would like to sort this out.
    Regards
    Bob

    Reply

    1. Hi Bob,
      First inclination is that the turbo actuator vacuum is being effected/starved when you use the AC, thus not then functioning correctly (pulling the turbo actuator rod ineffectively). This is most likely a physical vac leak, split pipe or faulty reserve sphere (next to air box) The AC will draw some vac to operate the internal flaps inside the cabin etc, if the supply pipework to this or other related components is faulty then there will be a degree of vac loss/leakage. This could have an effect on the vac available at the turbo actuator, causing limp home (no turbo boost) this condition would NOT necessarily cause the dash MIL lamp to light. If the vehicle is otherwise mostly trouble-free then look here first.

      The auto gearbox will also cause limp home, but possibly with a combination of locking the gearbox into one ‘safe’ gear to prevent transmission damage. If you have had this competently repaired, then this I doubt will be the root cause of the on going power loss problem (which you have had all along) – this issue is caused by the transmission ECU ‘locking down’ the gearbox and limping the engine in a safe mode, this would normally give you a dash indication on the MIL lamp.

      I hope this gives you some pointers and its at least a little help to a painful intermittent problem. Let me know how you get on.

      All the best Steve

      Reply

      1. I have a problem but with a crafter vw made by mercedes. Seem to have a air noise when the revs drop back down to a round 900-1000.
        The noise seems to be coming from behind the engine in the middle somewhere.
        Start up the van and I dont have any nosie apart from the ticking of the vacuum pump what seems to be a normal fault. Drive the van for 5 mins and it seems to start making thus noise every time it drops the revs. Ect changing gear or stopping at trafic lights. Seems to be slowly getting louder. Just had to change the exhaust pressure sensor today at it was faulty and a new turbo hose last week. All seems fine with them.

        Any help would be great.

        Thanks
        Simon

      2. Hi Simon,
        Is this leaking sound perhaps exhaust gas?, maybe the exhaust manifold or exhaust to turbo flange connection is blowing. Perhaps when the engine is cold the leak is sealed only opening when the engine/exhaust gets warm. Did you disturb anything when you changed the sensor?
        Check this out.
        All the best
        Steve

  27. Hi Steve, I bought a 2010 mercedes sprinter 313 from a lease company 4 mths ago,at 64000 miles with full service history. Felt the van has never been right from the word go. Diagnosis from mercedes is low fuel pressure. Symtoms are when the vehicle is fully heated up it goes into limp mode, especially under load. Had numerous diagnosis so firstly changed fuel filter (Merc), secondly changed fuel tank including sensor, then took it to mercedes trucks, It was advised I changed the quantity control valve and replace broken studs on the inlet manifold. I Had this work done at a huge cost, only to find out the problem still exists. Mercedes have informed me the fault codes still exists but are “stored fault” in the ecu. For some reason the star diagnosis can’t communicate with the ecu to clear the fault unless this is a live fault?? Also the management light doesn’t seem to be coming on, which isn’t helping matters. Biggest shock was still to come, mercedes also inform me they have a mileage reading from the ecu of 237000 kilometres ( 147000 miles). I have done 20000 miles since purchase which equates to 127000 miles when I bought it. I contacted the lease company to be told the is a possibility the ecu could have been swapped from another van, due to a lost key( sounds like b… sh.t . Mercedes have confirmed that I have the original ecu for my van which ties in with chassis nos. I am now in limbo and left without a working van whilst mercedes contact technical to hopefully find some answers. Totally baffled, and wondered if you can shed some light to my problems.

    Reply

    1. Hi Craig,
      Seems you have some difficulties to overcome!
      My first feelings regarding the fuel pressure issue when warm (if they have in fact measured the rail pressure) would be:
      If the problems are in low pressure fuel delivery:
      Fuel delivery pressure sensor, this lies on the right hand side front (looking into the engine bay) pointing down, just below the intake manifold on the block, Tee’d into the low pressure fuel line. (You may have had this changed but from the description its a little difficult to be sure)
      If its high pressure the most common problem would have been the rail pressure regulator but it reads from your description that this has been swapped so discount that. There is a chance that if the HP rail pressure is actually dropping it may be the high pressure pump that is giving trouble when warm. Having re-sealed a couple of these that were leaking they are high tolerance devices and do wear, I can only imagine that maybe the internal components are worn not allowing full pressure once temperature has risen. This is the triangular pump on the front of the engine. A diesel specialist will be able to test this out for you, or maybe purchase a used good one for about £70 to £100 dependant on age. I feel having gone this far and pretty much discounted most of the common stuff the High pressure pump would be next on the list. The EML lamp does not always illuminate, it all depends on the level of fault, I am sure if the fuel pressure returned to normal the ECU would reset the LHM on next key operation.

      See here for a bit of background, makes interesting reading, look specifically in the paragraph regarding faulty HP diesel pump.

      http://www.dieseljones.co.uk/troubleshoot-a-diesel-engine.html

      The ECU does record miles/kms internally and also does the speedo pod, changing one does not change the other, its a specialist job to change the recorded miles on either so really unlikely if you have a service history to back up the claimed mileage. What may have happened is that the ECU is faulty and the recorded internal odo reading is screwed. This is further backed up by the inability of the STAR to read/clear the ECU – Indeed if anything can read it this should! Of course there is a chance just as the miles are reading incorrectly that the signal from the fuel rail is being interpreted incorrectly by a faulty ECU and giving rise to the problem you see.

      The ECU works in conjunction with the DAS module (Driver authorisation system) that lives behind the speedo binnacle/inside the column. If you could get this module, its matching key and main ECU you could swap the whole thing and see if any improvement was seen. The dealership have the ability to program a new ECU to your existing DAS and this would be the cheapest method, and you would be sure the ECU was of the correct type for the vehicle.

      All in all a very unfortunate set of circumstances that I hope they will soon get to the bottom of.

      Do let me know how you get on.
      All the best
      Steve

      Reply

    2. some great advice there steve ! I had a similar problem and i had to change the injector pump

      regarding the mileage – the ecu has clearly been clocked. i suggest you get advice form the police / governing body / solicitor. you may able to get some money back and hopefully it will pay for a new pump

      Steve where is your workshop based / called ?

      Reply

      1. Hi there,
        Its a largish job to change the miles shown on the speedo as it has to be done by dismantling the pod to get to the PCB then needs some clever clipping to the chips on the board. Also to get the display not to show ——– you also need to reprogram the ignition key unit with the new miles so that they correspond. This is also a dismantle it to the PCB job.
        Given that even if most of the miles were done prior to the first MOT and it was adjusted then, the service history would have not correspond with the dates/miles etc.
        I would still not rule out the ECU as possibly faulty as it all seems a lot of trouble to go to for a small financial gain and really I doubt a leasing company would not risk their reputation as they have usually made a huge profit over the lease period anyway.

        Interesting all the same.
        Regards
        Steve

  28. Hi Steve, great read. I have a 2001 Sprinter 316CDi motorhome, just got it (sold my reliable 312 Sprinter self build) and have had it go into limp mode a couple of times now. Not sure what sets it off but I drove through the last one and it picked back up after a couple of miles, the one before was after sitting in 2 hours of traffic, it went into limp, pulled over to take a look (and google it) then after 30mins of faffing around drove off to find a garage but it was working fine so carried on (no issues again on that trip of about 140 miles until the next trip where it went after about 30 miles) – no indications on the dashboard just restricted revs of approx 3000 and a severe lack of power.
    Does this sound like a control valve problem, I’ve had a look for any obvious leaks, wiring problems and all looks good? Have a Mercedes garage nearby but want to use the van (and have enough problems sorting out a supposedly fixed leak in the roof!)
    Many thanks
    Simon

    Reply

    1. Hi Simon,
      Strange that it should occur after a period of time stuck in traffic idling. Maybe its fuel related. Have you changed the diesel filter recently? This would be my first point to address.

      Secondly I would be looking toward the camshaft sensor, it sits on the back top of the rocker cover and gets some real abuse from temperature extremes. iIs more likely to go faulty when it gets hot. This would be my second stab in the dark. Obviously a code read with a good MB compatible reader would be the best starting place as its ‘parts darts’ without this info.

      Check out the brake light switch above the the pedal, make sure its working with a test meter. Its a dual switch one side operates the brake lamps the other tells the ECU brakes are being applied – common problem and a cheap fix.

      It goes without saying turbo boost leaks are the most common cause of limp-home activation and you should check in the hard to see places such as the connections to the intercooler where oil staining will be the giveaway there is a leak, if its all clean and tidy then it is generally leak free. The big hose that goes to the inlet manifold splits underneath where you cant see it, remove the hose and flex it all over and look for cracks/splits.

      Let me now how you get on.

      All the best Steve

      Reply

      1. Many thanks for the reply – I have booked it in for a visual inspection and a fault code check on Tuesday, I’ll report back afterwards, I just hope they know what they are looking for as I have had parts replaced in the past on other vehicles that didnt resolve problems.

        Would the Filter (no idea when it was last changes, I think about 6000 miles ago) or cam shaft sensor leave a stored fault code as the problem is intermittent it would be my luck they cant repeat the issue when they have it?

      2. All codes should be stored Simon, a blocked or reduced flow diesel filter will normally flag ‘fuel Low Pressure delivery pressure faults’, and the Camshaft sensor will flag ‘camshaft and crankshaft synchronisation error – no camshaft signal’ Brake pedal switch -‘brake signal implausable’. Good luck Steve

      4. Had the Sprinter in today and got the following codes
        P0703-001 Brake Signal(CAN)
        P1470-016 Charge Pressure Control – Charge Pressure is too low

        Discounted the Brake signal as last time this was recorded was over 10K Km ago. Advised to check the following: cable routing from the Boost Actuator valve for chaffing (take bumper off), if no problem then change the Boost Actuator valve, if not resolved then could be the turbo itself, if not that then the ECU.

        I purchased a brake switch (just in case and it was cheaper than ebay) and a Boost Actuator Valve. I’ll check the cable tonight then take the van out this weekend (about 300 mile trip this time) and take the boost actuator with me and change if the problem persists. There were no codes on the fuel pressure or camshaft sensor so I guess its narrowed down a bit.

      5. Hi Simon, this a classic boost leak code, split in pipework, cracked or holed intercooler or poorly secured hose clips. Have a second look around. Inspect the turbo by dropping off the intake hose, grab hold of the spindle and see how much play you have (engine off of course ;)), there should be some up and down play and this is quite normal, check the vanes for damage and see if anything has been catching. Hopefully all will be ok and no bits will be missing from the blades! Is there excessive oil in the turbo mouth? – again some is acceptable and frankly normal in this set up. Lets see what your 300 miler brings, drop me a line when you get back.
        All the best
        Steve

      6. Ended up changing over the boost actuator valve before the journey and 250 miles later, no issues. Thanks for your help, hopefully the problem is solved.

  29. This is a great post. I have a non functioning boost actuator valve. No movement on the actuator but good vacuum. If I bypass the valve the vanes in the turbo start howling nicely. I found the voltage to the boost actuator valve was mvolts not 12v. Traced the wire back to the ECM and still got around .4 volts I actually cut the wires because I thought maybe they were shorted somewhere . Pigtails right from the ECM with the key on run 0.4 volts. Running stays a steady .4 volts. Does this mean something is wrong in the ECM? Any idea what to check next? Van runs very nice gets around 24 mpg but absolutely no power.

    Reply

    1. Hi Kevin,
      If the signal from the ECU is telling the boost control actuator to ‘not function’ then there will be little to no voltage on the actuator. I would look more into what is causing the ECU to go into limp home and disable the actuator. Its likely this is the result and not the cause of your problem. The van really needs a code read to find out what is the root cause of the limp home. I think this would be your best bet at this point to get some direction of where to start.
      Let me know what you find.
      All the best
      Steve

      Reply

      1. Thanks. I’ll let you know what I find. Do I need to go to a dealership for this? I have a good OBD2 code reader setup for my laptop (autoenginutiy) however I can’t locate the plug for OBD2 on this vehicle, 2002 140″ wheelbase.

      2. Hi Kevin, perhaps have a search on the web for an independent Mercedes specialist nearby as dealers will always charge premium rates for any work. Most good independent’s have the right equipment for the job. Do not discount those that specialise in MB cars as they are most likely to have the Mercedes Star Diagnostics (or compatible) needed to accurately read what the faults are.
        The diagnostics plug will be a 16 pin round female connector up by the bonnet release on the near side under the glove box. You may need a 16pin to OBD adapter (on ebay for about £10) depending on what you have available already. You should get a reasonably intelligent read from the equipment you have.
        All the best
        Steve

      3. Steve, I was able to have the codes read and have two active codes p1470-8 Charge pressure control has open or short circuit and p1403-4 EGR cable short circuit. There was also a stored p0600-4 Databus faulty. What are the expected values on the wires 1,2,and 3 leading to the EGR?

      4. Hi Kevin
        If its a 3 wire EGR then MB colour codes should be:

        Red – +12v
        Brown – 0v
        Grey/yellow – PWM

        Engine on idle, PWM 3.5V (ish), +12V 14.00-14.50V Bare in mind that its pulsed voltage on the PWM and its difficult to read accurately without a scope but at least you can check supply and ground.

        Its more likely to be the cables to charge pressure control valve broken as these run across the front of the intercooler.

        I hope I have understood you correctly and have in mind the correct model.

        Regards Steve

      5. Thanks it is a 3 wire. I assume if supply and ground check out I may need a new EGR. Any way to test by applying voltage to the PWM and looking for movement?

      6. Hi there, If you remove the unit from its location in the manifold circuit and turn the ignition on without starting the engine, you should see the valve move between its stops as part of the system self test/calibration routine. I hope this helps.
        All the best Steve

      7. Thanks. I removed the EGR by unbolting it from the manifold but kept the wire harness in place. Had my son turn the key to run. Lights came up on the dash but no movement at the EGR. Tried again with keeping the EGR grounded to the manifold. Still nothing. Started the van and revved to 2500 rpm. No EGR movement. Physically worked the mechanism after removing the little black plastic cover. The valve opened smoothly and easily. Can I run power to the EGR to verify that it is bad? If so +12volts supply, -ground, and then another +12volts to the control wire?

      8. Ok Kevin, in my book looks to be faulty. However there is really no way to test the valve by applying voltages to the pins, its a servo motor and some electronic wizardry in there and can be damaged by just ‘bobbing’ voltage on. The signal changes are so small between open and closed that the only way to actuate the valve in a test mode would be using the Mercedes star diagnostic tool, or at least some thing similar.
        All the best
        Steve

      9. Your help is really confidence inspiring. Got a new EGR from europarts for $600 and plugged it in. I again cycle the key to run expecting a test cycle but there was no movement. Is it possible that the ECU will not test the new EGR until it is reset. If so is there anyway I can induce the ECU to reset or does this need to be done at the dealership? I did disconnect the ECU harness connectors and then reinstall it but there was no change. Thanks Kevin

      10. Hi Kevin,
        I am unsure if the limp home condition actually disables the EGR circuit or not. Did you compare simple resistance measurements pin to pin from the old to the new valve? Did anything look/test unusual?
        Its so difficult to fault find by email as its always a ‘best guess’ situation and I do hope we are going in the right direction! I have a Vito outside 2008 model (similar engine controls configuration) that when you turn the key off from running you can hear the EGR cycle. Its like a high pitched electronic hum/buzz that lasts for a couple of seconds after the engine stops. I have always understood and known this to be a self-cleaning cycle and is not uncommon on other makes of vehicle too – Ford Transit is another one that sings on ‘key-off’. The same noise usually occurs on Key on with engine not running (here is an instance where it is confirmed the Sprinter EGR makes a noise when turning the ignition on: http://sprinter-source.com/forum/showthread.php?t=35375 ) You are obviously not seeing/hearing this, therefore I am assuming there is still an issue or associated problem here.
        Here is a little general background reading on the function of the EGR and its control you may find informative or at the very least interesting (it makes reference to petrol engines but the working principals are the same): http://www.aces.edu/~parmega/efi/egr.txt it could help you out.
        Did you try the vehicle on the road – is boost back or is it still in Limp home?
        If you re-read the codes from clearing them, what codes remain. Maybe another clear down and read would tell you what you have rectified (or not) so far.
        I know it can be frustrating with these type of faults but a little reading without searching too hard will indicate many others with similar Limp Home problems that take forever to track down and lead back to different causes in many cases. I hope you are not too disheartened!
        All the best
        Steve

  30. hi steve I have a 2008 Mercedes sprinter 209 my fault codes are p1955 and p0101 and manegment light flashing changed maf sensor had it programed by a Mercedes star computer fault still there checked maf terminals power and earth ok and sensor wire back to ecu ok after looking further into it I notice turbo actuator not moving so I checked for power at the turbo actuator electric vacuum control valve 2 wires. put ignition on got 12v start van and it looses earth . disconnect the plug and earth comes back plug back in and turbo starts working with earth back on why is this happening
    regards joe

    Reply

    1. Hi Joe,
      Both electrical connections to the boost actuator control valve come directly from the ECU so there is no ‘real’ earth. The electronics within the ECU control the valve by PWM that is turning it on and off in pulses. There is a chance that the wiring from the ECU to the actuator control valve has problems. It seems strange that this is happening but I would have really expected a Star reader to give the exact reason for P1955 P0101 as these are generic codes often read by non-Mercedes code readers that do not recognise the specific fault logged (Often the case with non MB readers and not unusual) Interesting read here that may shed some light on your issue. Let me know how you get on.
      All the best
      Steve

      Reply

      1. my mistake the codes I gave you were off a cheap hand held code reader I cant remember the code of the star but it said something like low boost pressure which I belive is because the vacuum solenoid is not closing the waste gate I have traced the cable back to the bulkhead and they go inside the van do you know what numbers they go back to on the ecu ?
        thanks joe

    1. Hi Joe,
      If it is P0299 this would be low boost pressure, this would fit with no/poor turbo actuation. Is this a manual gearbox van? Autobox issues can cause the turbo control to go into Limp home without any issues with the engine itself. Look for this 52 pin connector on the ECU. I think this will the be the diagram you need.
      Sprinter ECU Connector pinout
      All the best
      Steve

      Reply

  34. is there a way to reset the computer so i can get a 2002 sprinter out of limp home mode, so i can take it to the dealer and get it fix.

    the closest dealer is 45 min away and i dont think driving all the way on 2nd gear is good for the truck.

    Reply

    1. Hi there,
      You are pretty much stuck with it I am afraid, likely its a Sprintshift auto gearbox you have there, it will be locked into that gear until you get it out of LHM (Mercedes safety feature). If you had a manual gearbox model with vac turbo control, then there is a way to rig the turbo to get you to a garage with a little boost up to a maximum of about 3000rpm. With the auto box there is no getting around this problem. There are a few mobile auto techs with the capability to read the error codes on this vehicle and possibly get you fixed and running again without getting to the dealer. Sorry I cannot suggest anything else.
      All the best
      Steve

      Reply

  35. Hi Steve
    My mechanic has told me that our van has fault code 2078 and says to check component B28/8 (pressure differential sensor (DPF))
    Plausibility error with ignition on.
    Can you tell me what I need?

    Reply

    1. Hi Dave
      This code refers to Diesel particulate filter differential pressure sensor, either the sensor is faulty or you have damaged wiring to the sensor or in the harness. ‘Implausible’ usually means either +12v or 0v signal is recorded often due to wiring damage (If fault still present after sensor replacement)
      Good luck
      Steve

      Reply

  36. HI Steve

    Problems again with my 311 cdi After following your advice I have managed nearly 4000 miles in it with the odd occasional turbo problem. Today it decided to offer me a new problem stopped and started the van loads of times today. I was at my last job about to go home dash flashed up StArt error with capital s and a must be major, anyway van would not turn over so guessed it was something to do with the imobiliser stopping it. I then sent the wife home for the other key still no luck ended up towing it back home with my car. I have done a little research most of it seems to say it is going to cost me a packet one post reffered to a solenoid that fixed it for one person but does not mention what it is or were it is by the way plenty of charge in battery the only other thing that happened was it blew the fuse that controls radio and some other things van is 2003 lwb. So i am guessing a new immobilser and reprogramme of ecu, ecu has not long ago been remmapeed not by me by previous owner.

    Reply

    1. Update I got it running again after I pulled all fuses again for the 3rd time it reset itself? it started, a bit of basic test it see if it works showed the horn not working so more investigations anyway just posting the update so everyone else sees how I got going again.

      Reply

    2. Hi there,
      I would first check out the fuse box under the steering column, there are known power distribution issues and a resulting Start Error is not uncommon. I have a section covering this fuse box in the blog. Also check the wiring in and around the steering column and surrounding areas, there is a key code receiver coil that surrounds the lock barrel and this needs to checked, make sure its aligned correctly and at least plugged in securely. This connects to the key security module that lives behind the speedo binnacle. (about the size of a fag packet, black plastic) It may be worth dropping the speedo and making sure its all Ok behind there too. (worth a look) The key module is programmed to the ECU, its quite easy to swap out along with the ECU if you can ‘borrow’ one from an exact same spec van. This would be a sound way to prove the issue before spending a great deal. I would personally look for a wiring issue , what with fuses blowing etc… Its not really a common problem that the key unit itself fails. Let me know how you get on.
      All the best Steve

      Reply

      1. This get out of jail free card sometimes works in Start Error situations.

        I. Turn ignition key to “on” position (do not crank)
        II. Disconnect negative battery terminal
        III. Turn ignition key to “off” position
        IV. Reconnect negative battery terminal
        V. Start engine

        Look into the ‘Horn fuse’ problem as this fuse feeds SKREEM (Key module) circuit.
        Regards
        Steve

      2. Hi Steve

        I will take a look at it properly on Sunday unfortunately for me I have got to use the van on Saturday, been out in it today and all was well. The fuse that blew controls the cigarette lighter come radio the radio is not the standard one as there was no radio when I got the van only the universal wiring harness which just plugged in to my existing radio. The horn has had a wiring job done on it before I traced one of the wires back to the bulkhead it goes in through a rubber grommet. I gave it a wiggle and think it may be a poor connection as afterwards the horn worked again but will follow your advice and take a good look at the fuse box and the wiring behind the speedo. I will let you know what I find.

        Cheers Rob

      3. Rob,
        The horn wire passes over a welded lip/seam on the top of the front cross member, left hand by the headlamp, behind grille as looking at front of van. There should be a protective trim piece over the weld seam but it is is often missing. The wires to the horn sounder (that is also located here) pass over the seam and with vibration in time wear through, shorting on the unprotected chassis lip causing a break or short. Its worth a look.
        Steve

      4. Hi Steve

        A bit of follow up on the van decided to start passenger side lots of redundant wiring from it’s parcel delivery days some of which was still live, they had just cut the wires and left them. I have removed as much as I can trace, some goes under the van not attempted that yet always seems to be raining when i get a free moment. I have tidied up, re soldered wires and insulated them finally took out the speedo and skreem unit no problems behind here all connections good. The fuse box has given me a bit of trouble the bolt that holds it in just spins. I have started drilling out the head of the bolt to assist removal but not got it out yet, But on a plus side I now have usb charger in the van in place of the cigarette lighter lol. I will update again when I get the fuse box out.

    3. I had this problem . What I did was sent the ECU off to get ” reset”. This cost £ 150. When I got it back the problem was the same.
      Next I removed the speedo to get to the immoboliser box. Then checked what power was getting to each wire . I wrote it all down . Then I got my other van that was good and did the same.
      When comparing the results I found one wire on my faulty van that should of had 12V ( but had none)

      One hour to diag and ten mins to fix.

      Reply

      1. Hi Just an update van has not thrown the problem at me again but I have now had time to remove the fuse box. Sorry it took me so long my excuse worling and the weather. Anyway after removing the fuse box I did find the black wire that goes through the bulkhead to the horn, was spliced into another wire for power it was connected with one of those plastic clip connectors when time allows will solder it in. I also found another wire spliced into the black and red it was fused after messing with it and relocating an earth wire (not the one on the steering coloumn) it turned out to be an extractor fan in the back of the van so my dogs now get to stay cool in the summer it has not worked since I got the van.
        The fuse box itself showed no real signs of any problems a bit of tarnishing on a couple of pins cleaned them off the only real problem I found was no7 fuse was not making proper contact with it’s holder a pair of long nose pliers sorted that out, But in true sprinter fashion my heater has now become intermitent lol there is one big power connector near the heater under the bonnet that requires my attention due to some corrosion on it hope that sorts it out.

  37. Hi Steve
    I have a 5 silender 2,7 CDI engine that has very strange behavavior, It is very powerless under 2000rpm, and is realy dangerus is trafic due to its very poor accileration. The boost actuator engades when the engine is started up but does not move at all after that when reving up., After 2000rpm the power is ok, but not exelent. When I floor it in neutral from low idle it takes up 3 seconds to reach 2000rpm. and it is even slower when driving it. What would you recomend me to do?
    Best regards
    Helgi from Iceland

    Reply

    1. Hi Helgi,
      You really need to start with a code read to find the area of problem. Quite often the main issues are boost pressure leaks in split pipes or poor connected hoses from the pressure side of the turbo, through the intercooler, and to the manifold. Any problems here will set the engine into limp home (the symptoms you have). A code read will tell you all you need to know, find a local independent MB dealer/auto shop and get the codes read first. This will give you the best chance of a fix.
      Best Regards
      Steve

      Reply

  38. Hi Steve Brilliant info very useful indeed, iv read through & have not come across the problem I have so if you could help it would be super, I have a 2005 Sprinter 903 Mk2 Curtain Sider which drove perfect no problem at all until 3 weeks ago it suddenly went into limp mode while overtaking a fully loaded HGV very ashamed I was too when the hgv left me in the 2nd lane almost stationary lol & has been no better since. To make it worse when I have driven a few mile (which can take a while) if I turn it off it will not start at all & almost sounds like its out of fuel, if I leave it half hour it will start first flick of the key I can drive a few mile before it goes into limp mode again, I have another Sprinter that goes into limp mode now & again if you dip clutch turn key off & on again lift clutch up its fine again but that cant be done with this one as it wont start again, tank is full of fuel & iv had a new mb fuel filter fitted as well as new pipes to the filter. It never fails to start first thing its only once it has been driven for a few miles, no warning lights come on dash so im stumped what it could be. It has been checked for air & fuel leaks but all fine. Can you shed any light on it please. Thank you Kerry

    Reply

    1. Hi Kerry,
      It sounds like it could be a thermal problem with the camshaft sensor. This lives on top of the rocker cover at the back. All the symptoms you have would point to this at a first guess. You would really need a code read to be a little more certain of where the problem lay but that would be my first line of approach if I had no access to a diagnostic reader. OE PART NUMBER 0031539728 / 32317.

      Regards Steve

      Reply

  40. 2004 Sprinter 2500 no turbo issue. I have taken off every hose to turbo to inspect for leaks. Changed the actuator. Still cannot find the issue. It’s in permanent limp home mode. No check engine lights. Any words or advise?

    Reply

    1. Hi there, Check the ECU fuse 15a (Blue) under the steering column. There are 2 rows its the right hand row fourth or fifth fuse up I cannot quite remember.
      All the best
      Steve

      Reply

      1. I found the problem was a broken wire the cable bundle on drivers side top of engine was rubbing against manifold and tore through. Patched that up and turbo responsed as it should! Couldn’t see the tear under the cable at first!

  41. I have a Mercedes Sprinter 2010 316 Chassis Cab with a Luton back. It has a flashing engine light on the dash and ODB codes of PBac 07E8 and P2263 07E8. It says the Turbo boost pressure has a fault.

    Our mechanic has changed the EPG Valve and cleaned the Diesel Particulate Filter but the issue still exists. The Turbos seem to be spinning ok and the vacuum tubes seem to be ok.

    When I start the van the two actuators on the turbo don’t move at all even under revs. The engine pinks slightly and not all the time. When I reset the ODB codes all is ok until I put the engine under load (by going up a hill or accelerating over 3500 revs) then the light comes back on and it goes into safe mode.

    The vacuum lines go to a covered box on the right of the engine that needs a E10 star bit to remove it, is it worth checking this and if so how do I do it….

    Any ideas greatly appreciated as none of our local garages seem to know what to do or look for.

    Reply

    1. Hi Grant,
      The normal state of affairs is that the actuator rod pulls the turbo lever down as soon as you start the engine, but I think you have already worked that out. I had a problem on a luton box with these exact symptoms and it proved to be the turbo was not producing enough boost to sustain the correct pressures and going into limp home. This was the first sign of the turbo needing replacement.(It had gone from occasional limp home to happening more frequently as the turbo got worse) All the other sensors actuators were all fine.
      Can you look at the boost pressure in Live-data? Physically inspect the turbo by spinning it by hand and lifting the inlet impeller to see if it worn, pay special attention to the inside of the housing if there is any marking from the vanes on the inside of the trumpet you will need to replace the turbo. Make sure that there is not excessive oil passage to the inlet tract, pull off the induction hose on the inlet manifold, whilst a little oil is permissible a lot is a an indicator that all is not well.

      The fact that the actuators are moving indicates the control means and vacuum is functioning correctly so my guess is the fault lies in what is causing the limp home and resultantly shutting down the turbo actuation.

      I hope that has been of some use.
      All the best
      Steve

      Reply

      1. Hi Steve,

        The fault still exists and after taking it to 4 garages who have replaced various parts still no joy, so I decided to have a go myself. I have spend a day checking the following.

        Firstly my van is a 2010 316CDI (60 Plate) which does seem to differ from the description about. According to the man at Mercs parts counter it doesn’t have a vacuum pump…

        The fault is neither of the two actuators on the turbo move when the van is started and when its under load it goes into Limp Mode. No fault codes show up on the ODB scanner.

        1. I mentioned before I had a tapping sound, this turned out to be low oil levels and a dirty air filter. One replaced this went away.

        2. I have checked all the rubber pipes and cant find any splits.

        Checked the two actuators on the turbo, if I connect the main vacuum feed from the master cylinder it will move the actuators ok.

        Replaced the two vacuum actuators one at the front of the engine at the top left and one at the right hand side low down at the back. I have between 10.8v and 13v on the wires going to these actuators.

        3. The ECU wires under the dash seem ok, not signs of corrosion etc.

        4. The Turbo again seems of, I looked in the front and can see not scoring and no play detected either in and out or vertically can be felt by hand. Spins ok when the engine starts.

        5. The pipes from the two actuators are fed by a triangular shaped reservoir on the top right of the engine. A vacuum supply is going to this but in its off and running state the actuators seem to be venting to air. Ive replaced this for a new one too.

        I had the please of someone stealing the DPF, sensors and the two vacuum pips on the DPF over xmas so that all new too. Thats another story as to how they opened the bonnet and what they took. I now have two locks fitted to the exhaust and DPF….

        The only bits I haven’t replaced are a valve that is fitted low down on the right hand side of the engine just behind the EGR valve. I also cant work out that is at the other end of the vacuum pip that goes from the brake master cylinder across the engine bay to the bottom of the engine on the right hand side?

        I am really a bit lost now, so any suggestions would be appreciated.

        Cheers

        Grant

      2. Hi Grant, My son has a 2004 311 Merc and his van has been showing the same simptons, and constantly going into Limp Mode.
        Apart from doing a full service on it for him, yesterday I changed his temperature sensor, the one under the fuel filter. It was very badly worn and coroded. The part cost 5.72 from Euro car parts, and his van is running absolutely fine. He used it all day yesterday and is still out in work tonight and has been driving it since 7am this morning and it is running great and not gone into limp mode.
        Hope this helps, it seems to have solved his problem.

      4. Hi Grant,

        The fact that there is no movement of the actuator on start or drive indicates the fundamental problem seems to be that the van could be in Limp mode even before you begin to drive it.

        Interestingly there is a low cost common problem that often causes similar problems and this is the brake light pedal switch. This is a dual switch affair, half of it bringing on the brake lamps and the other signalling the ECU that brakes are applied. Change this switch above the brake pedal or test it out if you are electrically minded. (there are 2 independent sets of contacts in the plunger housing)

        The vac pump sits on the front of the engine and supplies vac boost to the brake servo. This vac is tapped off and used in the turbo boost control and environmental heater flap circuits. It may be the EGR valve is faulty, not closing or is stuck/broken – not uncommon. The valve that controls the turbo boost actuator can be tested to some extent with an ohmmeter for coil continuity but its internal function is more complex and not unknown to failure.

        It is getting to the point where you may need to either pay for the vehicle to be connected to a Star code reader at a good independent garage or purchase an Autel or similar unit to find out exactly where the fault lies. Parts are not cheap and to keep fitting replacement parts on the off chance of a repair is not really financially viable.

        Check that brake switch first then investigate the EGR. Consider your next move carefully, if you intend servicing repairing in the future then a capable MB specialised code reader could be a good investment.

        All the best
        Steve

      5. Hi Steve

        I forgot to mention, I have changed the brake and clutch switches already as I read this in one of your posts. I did this on my Vito when it kept blowing the brake light fuse and it fixed that too.

        The EGR valve has already been changed by one of the garages as they suspected it however it didn’t fix the fault. The EGR value is quite a simple device with as it only has two terminals and can be tested with a multimeter.

        I have paid twice to put it on a star tester but no codes show up except emission issues. The common comment from the garages is its a newish vehicle that they don’t know yet and they don’t seem to know where to start. Unless the Star tester says something specific they are at a loss. The parts are not too bad from Mercedes, it is cheaper if you are willing to change bits yourself especially when a none MB garage charges £60 an hour and they still cant fix it.

        Just one question are you sure the vacuum pump is on the front of the engine as the MB service desk said this model doesnt have one? Can you describe it?

        Many Thanks

        Grant

      6. Hi Grant,
        Unless I am thinking of entirely the wrong engine, this should be the vac pump here. However I may be mistaken. If the late model you have does not have a vac pump what arrangement do you have for generating vacuum for the brake servo etc?

        Mmm seems as if you are pretty well covered with the basic stuff and have already spent a small fortune getting to the point you already are. I will have to do some thinking and get back to you… Not beaten yet!

        …………

        Have a look here, some interesting reading about faulty backpressure sensor holding off turbo boost: Worth a look, especially as no codes are showing (though I really find it unusual that nothing is reported from MB star)
        http://www.sprinter-rv.com/2013/08/09/sprinter-losing-power-how-to-figure-out-the-problem/
        Steve

        Just a thought you don’t have any BAS ABS ESP related warning lights on as a fault in these systems can hold off the turbo/limit the engine.

      7. Hi Steve, Thanks for your help up to now!! The VAC pump pipe goes between the brake servo mounted on the bulkhead drivers side across the back of the engine and right down to the bottom of the engine on the right. It has a T half way that feeds the triangular vacuum splitter. This has good vacuum pressure it seems to be loosing it from here on. The only buts I haven’t changed are the temp sensor and the last vacuum switch at the back of the engine on the right hand side.

        Its interesting that none of the garages know how to diagnose this or test the various sensors and valves, maybe a tester needs to be developed as these newer vans are going to be unfixable to the smaller garages.

      8. Hi Grant, with regard the last statement: I think that is what manufacturers want, they no longer make the big bucks in a competitive sales world so have to re-coupe the profits through maintenance and service.

        Do let me know what you find, there should be a non return valve in that main vac line, it is usually at the servo reserve, the accessory vac take off should be forward of that and not taking any part in the non return action – when there is vac there should be vac!

        Regards
        Steve

  42. i have a fresh boost / low power problem

    (i have fitted a new solenoid, boost and temp sensors recently – the problem turned out to be a split intercooler. the actuator was a bit stiff and a hard tug sorted it out)

    now i have a new problem – the van goes into limp home mode immediately – it does not over boost first and then loose power

    i am guessing this must be something to do with the pressure sensor ??

    the van is flat on power in all gear and struggles to run over 50 mph

    (i will check for a loose boost pipe in the morning)

    sadly i don’t have a fault code reader or know anyone who does

    i will post my findings on here

    Reply

      1. Hi Steve – I checked every fuse – they were all fine

        couldn’t find any boost leaks either

        i put my finger over the bottom pipe on the boost solenoid and i can see the actuator move up and down – something i did notice was there was a bit of a rattling noise when the actuator was at the top of its travel but only at the top

        do you think the turbo vanes are broken and that is why i am getting no boost ?

        any suggestion greatly appreciated

      2. Hi Mike
        The turbo is not boosting when the lever is in the up position, when pushed to the bottom of its range, or under vac, you should hear a howl from the turbo when you rev the engine (better if you remove the inlet pipe to the turbo. If you have a good noise then likely the vanes will be OK, the rattle is probably the pivot as when its in the most upward position the lever is under no pull from the actuator shaft so is unsupported. You are kind of stuffed now without the ability to read the stored fault codes as this would be the biggest insight as to what was going on. Let me know if you find anything.

        All the best Steve

      3. HI Steve,

        i got the fault codes read yesterday and reset – the van drove great for about 1 minute and then went back to low power

        the new fault code was a 1470 – low boost pressure

        the code did not point to any particular module / sensor

        any suggestions ??

      4. something i forgot to mention i could hear a bubbling noise when the van was turned off

        the valve appeared to have some water in it so i took it apart and cleaned it out

      5. an update – the van will not rev past 3500

        does the van think it is not in gear ie in neutral ?

        is it normal to rev to only 3500 when in limp home ?

      6. This is itself an indicator of limp home mode Mike. However if you are out of gear stationary it is normal to not rev above this, this is a feature that can be overridden by depressing the clutch while the engine is idling and releasing it sharply in neutral of course, then stamp on the accelerator and it should if working correctly rev above the pre-set limiter.

        It has been known that clutch switches go faulty above the pedal but its not common, not as common as brake light switch that usually causes this kind of problem.

        Regards
        Steve

  43. Hello Steve
    Wondered if you could help, I have a Mercedes sprinter 313 it seems to be lacking power and the yellow light keeps coming on.
    I have had it on the diagnostics and its coming back that number 4 injector is not being recognized, I’ve also had it in with a recognized Mercedes specialist who cannot rectify problem any advise would be appreciated.

    Reply

    1. Usually if the injector is not being ‘recognised’ it is a faulty injector. Its ID cannot be read by the ECU and calibration settings cannot be entered or applied. Has the injector itself been replaced? That would be my first port of call.
      All the best
      Steve

      Reply

      1. Hello Steve
        When I bought the van from the beginning the van was lacking power I put van into Andy Gayles Birmingham they identified that maybe previous owner may have put petrol in vehicle so they ended up changing injectors 1 2 and 3 but when they tried number 4, new injector was not recognized they tried another 2 injectors but problem still was there.
        That was 6 months ago now Engine light keeps coming on and vehicle loses power I have tried another Mercedes specialist who is also coming up against same problem.
        Thanks for any help.

      2. This is very strange the communication does not seem to be fully working to the injector via the ECU. You may have a faulty ECU but due to its position under the dash it is not uncommon for water to run down the loom and start to corrode the pins/connectors on the ECU module. Pull out the ECU and remove all the plugs and inspect the contacts and plugs. Remove any green or corrosion from the pins and use a contact cleaner spray on the plugs. This may work. Its a strange fault and not an easy answer I am afraid.
        Let me know how you get on
        Regards Steve

      3. Just an idea. I changed out the engine wiring loom in my sprinter. It cost about £ 270 from main dealer and I fitted it myself.

        Once done to was like a new van.

        Anyone know where I can by the engine wiring loom cheaper?

  44. Hi Steve:
    I have a 2004 Sprinter. I occasionally have had a problem with engine going in to limp mode. Shutting down engine and restart results in proper operation. It would then work for months without fail. Recently it failed and the intercooler hose had cracks in it and was replaced.
    Turbo worked perfectly for a week and then started failing after driving a few miles. Again shutting down and restarting would work again for the rest of day or several days. Took vehicle in to dealer and they feel turbo needs replacing. They can’t get a failure code for this 2004 model but feel eliminating 3 other possibilities, this is the most probable cause. Would appreciate your input.
    Thanks!
    Fran T

    Reply

    1. Hi there Fran,
      There is an outside chance your limp home condition is being caused by some thing other than the turbo. When was the fuel filter last changed? Have you problems with the rear lamp clusters? It maybe you have a faulty brake light switch above the pedal, this is a common fault. If you cant read the ECU faults yourself do the simple and cheap things first then take the vehicle to a good independent for a code read so you can actually see where the fault lies.
      Hope this helps a little.
      All the best
      Steve

      Reply

  45. Thank you so much for making this info so easy. I have three sprinters with this problem and I have been putting off dealing with it as the vans still drive . But the driving experience is nothing nice.
    I do all my own maintenance because I have no money and got tired of garages jerking me around ( I used to have money).

    Brendan.

    Reply

  46. my 2002 Spinter was also in limp mode and a new wiring harness (the portion that runs through the intake manifold fixed the problem.

    Reply

  48. Hi there,
    very interesting article and well documented.

    Well I don’t have a Sprinter but my problem is similar and I can’t solve it for a while now….spent lots of money with mechanics with no luck. I don’t have any fault code on my obd2 scanner. I changed with 2 different valves with no luck. After all the tests and checks my conclusion is that it may be related to the ECU. If I connect 12V directly to the valve the actuator is moving and I have boost. The voltage on the plug is 11.2V(constant with the engine started) I checked the connectivity between the plug and ECU and is fine(blue cable) the blue&black cable goes to a relay which Is fine(I swapped it with an exact model ) ..also the connectivity to the relay box is fine. So I assume for some reason the ECU is not sending signal to the Valve ….are there any other sensors/valves that may cause the ECU to act like this??

    Thank you.

    Reply

    1. Hi Johnny,
      There are many factors that can hold the ECU in limp home without illuminating any warning lamp ( in effect, holding off the operation of the turbo boost control valve ) Its likely that your basic code reader is not giving you the exact cause of the issue. It could be anything from a faulty brake light switch above the pedal to a split in the intake hose, even the turbo itself! My advise would be to find a good independent Mercedes repair shop or even a MB dealer and pay for them to read the codes with a specific code reader and document them for you, depending on what they find either replace the faulty components yourself or entrust them to do it. You are pretty much in the dark without a dedicated code reader and the above would be my best advice.
      I hope its of some help!
      All the best
      Steve

      Reply

      1. Thank you Steve.

        I manage to go to a diesel specialist and he used a dedicated tester and still no faults apart for one of the glow plugs which I will replace soon. He said it may be the ECU. He even tested the contacts between the ECU and all the mains sensors/valves that may create a limp mode and all look fine. He didn’t cleaned the ECU contacts. Do you think this may be a good idea?? From the plug all the wires look good. He didn’t checked the injectors …. somebody said I may consider checking the injectors . I was thinking to go to the main dealer but when I called they quoted me some ridiculous price/hour for diagnosing complex faults like mine.

        Thank you.

      2. Hi Johnny
        This is a real long shot but I will voice it anyway. If your vehicle has been to an Auto electrician (not MB) for diagnosis of the loom there is a chance that the ECU connector was dismantled and the positions changed for connection to the boost valve. I am unsure where they sometimes get pin connection data from (I am assuming its listed in Auto Data but I am building a picture that its incorrect!) and they do re-connect it wrongly! This has happened twice to my knowledge once to me personally some time back. You need to have a look through the posts, I know there is a diagram with the correct ecu to boost control valve pin connecton numbers, if you don’t find it easily, drop me a line back again and I will get a link for you.
        Its a puzzler!! Injector problems would be showing poor starting issues I think, if it starts easily and runs OK then its elsewhere. You need to pull a vac on the turbo actuator itself, does it move the vane adjustment lever? Does this move freely with a hard push? Check all the fuses under the steering column especially the ECU fuse. Pay special attention to the loom where it hooks from the engine under the inlet manifold across the engine mount, have a good look here as its a very common fault the wiring loom chafes and shorts. You never know its worth a look. Don’t discount fuel flow as being the issue, if you have not already, put a new fuel filter on, get the service guy to look at the reported rail pressures though I would have expected he had done this.

        The key indicator to finding this fault is if the turbo actuator lever pulls down when you start the van, and it only trips to Limp home when you get moving, OR does the lever never move?

        I would not worry about the glow plug, most of my fleet as do all others have none working and they still start and run fine in all weathers.

        All the best
        Steve

      3. Hi Steve,
        really appreciate your help here.
        That’s the problem, is very weird because the vanes and turbo are all fine, if I connect a 12V(checking the voltage on the plug that goes to the valve is below 12v…..If i remember well is 11.2V constant) directly to the Turbo Boost regulator (vacuum valve) I have boost(the lever is moving) but because is not controlled by the ECU is going up to 25psi and I avoid testing this too much…But I can say I try to drive the car like that and is flying….proper torque and acceleration :)). Now to give you more details I replaced and tested the valve and is fine, When I start the engine the actuator lever is not moving…same if I rev the engine….When driving is acting like a petrol car…….low power up to 2500RPM then starting to work better…..also the MPG is 30% worst than normal. I replaced everything I could think about…..all the mechanics I ask about this are telling me the turbo is gone…but as an Engineer I think here is just a case of excluding possible faults/broken parts…..or at least that’s how I proceed with my servers …. :))…. Thank you again.

      4. Johnny,
        As you say the lever does not move, even at start up. The way the control valve works is the valve is pulsed (PWM Pulse width modulated) its almost like on and offs depending how much boost is required, during an off period the valve vents the actuator vac to atmosphere. This happens a few times a second controlled by the pulses given from the ECU. The normal working state on ignition on and running at idle is lever down, full boost, you should hear a howl like a banshee if you have the air box off! Its ok to run with the boost at full chat for a temporary period, 30 to 35 psi is not unusual in the intake and although not controlling as it should you will get drive home ability but it will consume diesel like a man possessed.

        What exact vehicle is it VW?

        The only other things in the basic circuit that can prevent the actuator not moving from the word go would be implausible pressure sensor (MAP) but I guess you are reading boost pressure from somewhere this gives an output in circuit measurable 1.2 to 5v dc depending on boost. Its a 3 wire, one ground one supply and one output. There is also an inlet manifold temperature thermistor check this is not busted. There is also a fuel rail low pressure switch in the fuel supply to the LP pump, if this is corroded or not working it will not allow turbo actuation as to protect the engine.

        Do you have sufficient vac to the actuator, often there is heater flaps driven from the same vac supply, there is a reserve (like a ball cock shape) in circuit, these do split sometimes as can the pipework. Check the tapping on the brake servo side of the vac pump supply behind the one way valve and ensure you have vac there even when the engine is off !! Pull the servo hose after a while of engine off and it should have a huge inrush of air, if not suspect one way valve. (You may have noticed a varied hard/soft brake pedal if this was an issue)

        As you can obtain boost by hot wiring then the turbo is proven as able to provide capable boost so its in the control circuit some where.

        Steve

      5. Just another thought, its not an auto gearbox is it? as a fault or code raised in the auto box controller can hold off the turbo as a fail protection, this is the case on MB auto boxes and Sprintshift’s. You have to clear the fault on the autobox before the engine restores.

        Steve

      6. Wow Steve, that’s a lot of new information. I can tell you are a specialist . It;s a Suzuki grand vitara truck(2007) manual gearbox with renault f9q engine which is very popular on a lot of cars and trucks/vans. You are right about the howl…I can hear it….and also I hear like a whistle when I bypass the vacuum valve…with proper boost. You are also right about consuming diesel like a train. The MAP I think is working fine..I can read the pressure using the OBD2 reader connected to my android app(torque). I also have the full service manual of the car and until now I manage to fix most of the small issues I had…problem is that the diagnose part in the manual is very basic with usual how too.
        I have no problems with the vacuum pump . It was the first thing I checked. As another detail I can tell you that first time this happen the car stopped completely then it was starting and stopping after couple of seconds…..and after multiple starts it was fine but with this problem….Maybe this can make you an idea about the overall condition.
        I’m sure you are right …there is something in the control circuit and probably I’m not looking in the right direction. For now you are the only one who manage to bring some light in this …I can tell you I spent over £600 and with a baby on the way I don’t think I will allocate more budget to this car…even if I love it and it helps me a lot….so I will probably give it another chance :)).
        Thank you again and if you can give me more info about the fuel sensor and the intake termistor I will be grateful.

  49. Have a 2000 311 cdi, approx. 148,000 miles. It had been standing for a long while before I bought it. It did have the EDC light on initially when we bought it so had all the filters changed, oil etc, new back end on exhaust and codes cleared at the time of oil change. and covered about 1000 miles with no problem at all. In fact it had been running beautiful, until about 10 days ago, when it just had no power/no revs above 3000. Called in to the garage explained the problem and seemed to be sorted by turning off ignition and restarting. This was intermittent for several days, and had several journey over a long distance where it was fine. A couple of journeys where I was on the move when it occurred and for the past three or four days its just been like it all the time. Restarting hasn’t solved the issue, so a couple of days ago, took it in and had a the codes read. These are the results from the print out.
    P1330-8 STORED&CURRENT STARTER ACTUATION – CABLE HAS OPEN CIRCIT
    P0600-4 STORED THE DATABUS IS FAULTY
    P0600-8 STORED TRANSMISSION OF THE CAN DATABUS MESSAGE WAS
    UNSUCCESSFUL
    P1615-1 STORED CONTROL UNIT CDI – THE VOLTAGE SUPPLU IS TOO LOW
    P1470-8 STORED CHARGE PRESSURE CONTROL VALVE – CABLE HAS OPEN
    CIRCUIT OR SHORT TO GROUND
    P1470-16 STORED CHARGE PRESSURE CONTROL – CHARGE PRESSURE IS
    TOO LOW

    The mechanic cleared these, drove home 11 miles with no problem but was back again the following morning. I just wanted to see if these codes could or would shed any light on the problem. Have replaced the boost pressure sensor and am currently about to go through the remaining advice, in your article at the top.

    Reply

    1. Hi Bruce,
      This looks like it could be as simple as a voltage drop problem, check all the battery to body earth points (there are quite a few around the battery tray) also make sure the battery positive/neg lead is good connection to the battery and not corroded and that the alternator is providing the correct supporting charge. Check all the fuses in the fuse panel beneath the steering column for white corrosion and generally have a good look round. Be sure to check the loom on the engine as it falls from the inlet manifold by the engine mount this commonly chafes and gives rise to a catalogue of electrical issues with ECU and engine control.
      Hope it helps,
      All the best
      Steve

      Reply

  50. Hie Bruce

    I have a Mercedes sprinter 511 CDI 2008. It was involved in an accident and the sump and starter went. The exhaust also was squashed. I have removed the exhaust. If I start the vehicle it starts very well. It idles and switches off. If I remove the EBP sensor it idles and drives but if I put it back it stalls. I bought another sensor but still the same. What could be the problem? I am a lay man. Thanks Bruce

    Reply

    1. Hi Bruce,
      If I have understood correctly then running the van without the exhaust will probably cause this issue as there will be no back pressure in the exhaust system and the 02 sensor reading will also be affected . Once the exhaust is back in place all should be Ok.

      All the best
      Steve

      Reply

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