EPC - Visit Workshop

[thepachat]

Hello everybody,

I'm new to this forum and interested in having some advices about an annoying problem on my 2003 S Class 320 CDI.
Since a year I search the reason of an EPC notification which occures when the engine is warm and I want to overtake a car for example. I've read many things on this forum and on the internet, so I first changed the diesel filter but nothing changed. Then I checked the low pressure hoses, but they are in a really good state.

The next step has been to read the fault codes, 3 problems appear:
2047-001: Rail pressure monitoring via volume control valve. The rail pressure is too low.
2015-001: Rail pressure monitoring via volume control valve. The rail pressure is too low.
2019-001: Rail pressure monitoring via pressure control valve. The rail pressure is too low.

With this messages I thought the problem had to deal with the pressure sensor, so I bought a new one, but still the same warning. After what I changed the quantity control valve, and finally the pressure control valve, but it didn't solve the problem. I also performed a leak off test, the injectors seem to be ok.

Has anyone an advice or already had the same problem ?

Regards,

 

[Alex Crow]

did you do the leak off test under hard engine acceleration, or just at idle??

 

[drdre78]

last time changed fuel filter

 

[Steve@Avantgarde]

Can only be a worn injector or 2 if you have done everything else. As Alex has said, a hard idle leak off test is what is required.

 

[Roxie]

Is the fuel filter a genuine Mercedes one? If not change it. If it is genuine look for air in the fuel lines. It needs to be clear of any air bubbles this could be getting in at any pipe connection before the low pressure pump.

 

[thepachat]

Thanks for all the replies !

I performed the leak off test at around 2500 rpm, you may be right with the hard acceleration, but I thought this would be bad for the engine to perform the test with a hard acceleration ! How would you recommend to test it ? Continuously at around 4000 rpm or prefer acceleration and deceleration ?

@Roxie: I can't see through the fuel lines (they are made with black plastic/caoutchouc), how much cost a transparent fuel line ? The fuel filteris a genuine Mercedes changed for 2 months (the problem was present before the change and continued after it)

 

[Alex Crow]

How would you recommend to test it ? Continuously at around 4000 rpm or prefer acceleration and deceleration ?

full throttle acceleration and decelaration, that way rail pressure goes high momentarily.

 

[thepachat]

I think I finally found the problem: a worn injector. After reading some forums about the EPC problem, it seemed that the problem had to deal with the injectors, so I started to check them. As I dismounted the injector number 2, I noticed that there was an important quantity of gasoil around the injector in the recess, so I changed it, and I think that the problem is now fixed.