Jerking Issue on 2008 Citroen C5 1.6 HDi Wagon

[aronmantal]

Hi everyone!

I have a 2008 Citroen C5 wagon (estate) with a 1.6 HDi engine and over 200,000 km on it. Unfortunately, the car jerks in every gear, at both low and higher speeds. It only stops jerking if I press the accelerator hard. It has been to my mechanics, but so far we haven’t found the cause.

One important detail: if I unplug the connector from the EGR valve, the car runs perfectly with no jerking at all.

I would really appreciate any experiences, tips, or suggestions. The MAF sensor and the EGR valve have already been replaced, but nothing changed and the fault codes are still there.

These are the current error codes:

P1459 - Evaporative Emission (EVAP) Purge Flow Switch Malfunction

P0490 - Exhaust gas recirculation (EGR) system - circuit high

P1351
- Ignition Coil Control Circuit High Voltage
- IDM input circuit Malfunction/Ignition coil control circuit High voltage
- SID 803/EDC16C3 - Pre/Post heating relay circuit.
- Relay not controlled and glow plugs supplied.

P0100 - Mass air flow (MAF) sensor/volume air flow (VAF) sensor - circuit malfunction

P0401 - Exhaust gas recirculation (EGR) system - insufficient flow detected

Thanks in advance for any help!

[mickthemaverick]

Did you tell the ecu that you had replaced parts? I believe you have to do so via the Repair section in Diagbox but I don't know for sure

[aronmantal]

I haven’t done this before. Is it something I can carry out at home as well?
And could you maybe help me with the process?

[mickthemaverick]

I'm afraid I don't know enough to help you with that. Hopefully one of our more knowledgeable members will be able to help.

[PaulC5]

Has the fuel filter been replaced ? A blocked filter might affect running but the fault codes have probably put it in limp mode.

Were the new MAF and EGR from a Citroen dealer or low cost copy parts ?

[aronmantal]

I bought the car about 2 months ago. The fuel filter was replaced this spring. The MAF sensor is original, and the EGR is an aftermarket part, but not the very cheap kind.

[PaulC5]

Has it been doing this all the time you've had it or just after filling up with diesel - just in case it is a bad batch of fuel. Asking in case the jerking is not related to the fault codes.

P1351 is something that many people would not be worried about.

[aronmantal]

Unfortunately yes, it has been happening since I bought the car. However, it’s getting much worse now, especially since the EGR valve was replaced. For example, it’s difficult for me to drive at 50 km/h because of the jerking.

[aronmantal]

The EGR has been calibrated (relearned), but the fault is still present. The car is jerking/shuddering, and the fault codes are still there. However, it’s possible that two injectors are not operating properly or are faulty. Could this also cause the jerking?

[PaulC5]

Another thing to consider is the high pressure fuel pump suction valve, have a look at the fuel pressure when it is giving the problem and see if it is stable. On a couple of occasions 2 years apart our C5 jerked, once on a motorway and cleared after a mile, another time doing around 50 mph. A diagnostic check did not show anything but both times the fuel level was low and the fuel was old. After filling up the problem went. I bought a new suction valve but never put it on due to difficult access and later sold the car.

[aronmantal]

The only way to fix the problem was to coding out the EGR valve from the system.
The jerking is gone now, and there isn't a single error message