2008 sprinter 315 twin turbo

hi i have a 315 sprinter twin turbo, the vehicle has EML on the fault code checked with a delphi computer the fault code is P1955 there is no description, however was told it was glow plug module, i changed glow plug module and glow plugs, how ever fault code wont clear! the fault code keeps coming back once cleared!
Can anyone help please, thanks

markyni104 said:

hi i have a 315 sprinter twin turbo, the vehicle has EML on the fault code checked with a delphi computer the fault code is P1955 there is no description, however was told it was glow plug module, i changed glow plug module and glow plugs, how ever fault code wont clear! the fault code keeps coming back once cleared!
Can anyone help please, thanks

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Have you had the vehicle adaptations reset?
Check all of your wiring as is may have a bad connection or a possible break in the cable from rubbing on the engine etc.

Sometimes leaving the battery disconnected overnight will get rid of gremlins that are stored on the ECU EPROMs.

Is the glow plug module new and made by the OE manufacturer?
If not then that maybe your problem.


Thanks, Sam.

the wiring has been checked the glow plug module is aftermarket, made by febi was told they are a good brand! will maybe swap this out first! thanks

markyni104 said:

hi i have a 315 sprinter twin turbo, the vehicle has EML on the fault code checked with a delphi computer the fault code is P1955 there is no description, however was told it was glow plug module, i changed glow plug module and glow plugs, how ever fault code wont clear! the fault code keeps coming back once cleared!
Can anyone help please, thanks

Click to expand...

A code is neither a symptom nor a diagnosis. Replacing parts based solely on a code is just guessing. Guessing is by far the most expensive and time-consuming way to repair a vehicle.

I have seen many people actually install additional problems into their vehicles, by replacing functioning parts with inexpensive aftermarket parts during the course of guessing.

I would recommend having it properly diagnosed instead.

I’ve heard of this code being thrown up because of a boost/vacuum leak too.........

The Grand Tour said:

A code is neither a symptom nor a diagnosis. Replacing parts based solely on a code is just guessing. Guessing is by far the most expensive and time-consuming way to repair a vehicle.

I have seen many people actually install additional problems into their vehicles, by replacing functioning parts with inexpensive aftermarket parts during the course of guessing.

I would recommend having it properly diagnosed instead.

Click to expand...

I would second this .
I have tried a Delphi scan tool! And in short not too impressed! My youngest brother loaned me one for trial ! He has a shop in Gloucestershire!
In fact Delphi in the USA is very US product centric policy and doesn't "do Benz very well"!
It will lead you up the garden path.
I do have three Autologic scan tools "2 blue box" "1 grey" plus others for my guys to use.
Its one of the few decent automotive diagnostic scan tool products that the UK makes and supplies worldwide, but expensive to buy.
You might want to call Autologic (in Wheatley Oxen) and see if they can locate a shop near you to do a diagnostic scan,

We don't have this exact Sprinter model in the US but the set up is similar to the OM651 in 2103 onwards Sprinters .

Yes vacuum can be a big problem and so can be the vacuum operated water pump clutch.
Essentially coolant gets sucked into the vacuum system and the liquid gets dumped into the engine crankcase simply by way of the vacuum pump which is mounted low down on the crankcase. If left for any time it will wreck the engine.
Although the pump has one way valve on it and visible . The 19mm plastic hose itself has a further one way valve built into it before it reaches the servo check valve. Its prone to failure !
On NAS Sprinters with the OM 651 the vacuum is stored in a wedge shaped vacuum tank near the valve cover . The bloody thing has a habit of separating itself at the base section & then leaking stored vacuum .
What I will tell you is that if coolant gets running through the vacuum system, it has a habit of wrecking the solenoids. So they should be checked and that includes vacuum hoses for leaks.
We use a vacuum pump to raise the depression to the a minimum of 27/28" HG held for 30 minutes .
Hope that helps
Dennis

hi thanks for the replies , the fault code comes back when cleared straight away the vehicle wasn't started just ignition on! if it was down to vacum leak would the engine not need to be running, thanks

Yes always remember though, that in these vehicles the vacuum control solenoid(s) that are all controlled by the PCM which in turn is CONSTANTLY monitoring conditions of the solenoid valves themselves ELECTRONICALLY .

In turn since the two stage twin turbo is actually controlled by a waste gate and boost control solenoid/vacuum valve/actuator arrangements (which are all monitored for precise control) the PCM is receiving input on their conditions.
Any "seen" malfunction will instantly flat a CEL & Limp mode.
Dennis