Citroen C5 X7 2.0 HDI 2010 EGR and anti-pollution warning

[mihkel]

Hey!

I'm trying to get to the bottom of a problem that has been with the car since I have had it. Now it's just getting more frequent so it should be more easily diagnosable. Drives and starts fine, no smoke, no noises. It's starting to go into limp mode or something similar more often now. I've noticed the anti pollution and check engine light come up when the car is accelerated quickly (overtaking for example). Sometimes it can happen during cruise. It loses a bit of power and the check engine light comes on. Also the cruise won't work after that. Sometimes the cruise control disengages even without the check engine light.

Re-occuring fault codes are as follows:

P1471 EGR butterfly - open circuit
P1671 Cruise control. Information incoherent

And some of the others I have seen over the time.
P0094 Fuel system
P0272 Injector flow correction 4
P0215 Injection system supply relay circuit (1 stage)

Fuel system faults seem to have been cured with injector cleaner and relay-fusebox contact cleaning. I'll read the codes again tonight.

One of the things I would like to check is the wiring between the ECU and EGR. Does anyone have a diagram for that?

Could the BSM be the source of troubles? I had intermittent no-start which was cured after the mentioned contact cleaning. I also saw some contacts corrosion on the BSM which led me to think I should swap it for a new one anyways in the future.

Citroen C5 X7 2.0 HDI 2010
VF7**************[VIN obfuscated, can be read by forum staff]

[mihkel]

Well... I checked the codes again and no EGR codes have popped up. Instead it's all related to the high pressure fuel system. The fuel filter has been changed recently. Could be the fuel pressure regulator or still the injectors? The car has half a million kilometers under its belt.
P0088
P0087
P1671
P0094

[GiveMeABreak]

There’s another possibility in that it may be the high pressure fuel rail sensor. These can fail over time although Citroen recommend not removing the sensor from the rail it can be done, but there can also be issues resulting so Citroen only sell the new rail with sensor already sealed. The best thing to do is to pop your VIN number up and I’ll have look at those fault codes as they relate to your specific engine ECU.

[RichardW]

As you appear to have both low and high pressure errors, and the trace shows the pressure wandering about, I would be tending more towards the actual regulator (which is part of the HP pump I think) rather than the sensor.

[mihkel]

There’s another possibility in that it may be the high pressure fuel rail sensor. These can fail over time although Citroen recommend not removing the sensor from the rail it can be done, but there can also be issues resulting so Citroen only sell the new rail with sensor already sealed. The best thing to do is to pop your VIN number up and I’ll have look at those fault codes as they relate to your specific engine ECU.

The VIN is VF7**************[VIN obfuscated, can be read by forum staff]
I guess the part number for the sensor can only be found on the sensor itself? OE catalog and aftermarket parts catalogs don't list the part.

As you appear to have both low and high pressure errors, and the trace shows the pressure wandering about, I would be tending more towards the actual regulator (which is part of the HP pump I think) rather than the sensor.

I would also tend towards the regulator on the HP pump as I have both faults. The OE part number seems to be 193339. Original is about 118€ and the only aftermarket I can find is Delphi 9109-927 for 82€. The Delphi might even be the original supplier.

[GiveMeABreak]

Here are some pointers based on those codes:

Fault Code:	P0087
Description of Fault:	High pressure fuel regulation: The measured rail pressure is too low in relation to the set point. The ECU detects a difference of 180 bars to 250 bars for 3 to 6 seconds between the rail pressure set point and the measured rail pressure.
Conditions for Fault to clear:	Driving for 5 minutes with several full load accelerations for 10 seconds.
Downgrade Modes whilst Fault is active:	Deactivation of processing of the accelerometry Deactivation of the speed limiter Deactivation speed limiter until the next time the ignition is switched on Deactivation of the cruise control Deactivation cruise control until the next time the ignition is switched on Request for Delayed Engine Stop Deactivation of the accelerometry strategies
Symptoms:	Jerking/stalling Diesel fuel consumption a bit higher Fluid leak/smells (diesel fuel, oil, etc.) Lack of power Starting problem
Suspect Areas:	Engine ECU (Software not up to date) Poor fuel or polluted fuel (petrol, deposit, etc.) Problem on the fuel low or high-speed circuit (hose, tank, diesel fuel filter, etc.) Fuel injector Electrical harnesses Connectors High pressure fuel pump Fuel pressure sensor

Fault Code:	P0088
Description of Fault:	High pressure fuel regulation : The measured rail pressure is too high in relation to the set point. The ECU detects a difference of 180 bars to 250 bars for 3 to 6 seconds between the rail pressure set point and the measured rail pressure.
Conditions for Fault to clear:	Driving for 5 minutes with several full load accelerations for 10 seconds.
Downgrade Modes whilst Fault is active:	Deactivation of processing of the accelerometry Deactivation of the accelerometry strategies Deactivation of the detection of loop difference on the fuel flow rate regulator Deactivation of the injector flow rate correction strategy
Symptoms:	Jerking/stalling Unwanted acceleration Noise Smoke from the exhaust Lack of power Starting problem
Suspect Areas:	Engine ECU (Software not up to date) Poor fuel or polluted fuel (petrol, deposit, etc.) Problem on the fuel low or high-speed circuit (hose, tank, diesel fuel filter, etc.) Fuel injectors Engine fuse box Electrical harness Connectors High pressure fuel pump Fuel high pressure sensor

Fault Code:	P0094
Description of Fault:	Fuel system : Incoherence of the fuel pressure measured with the flow regulator too open. Excessive under-capacity of the injection system to provide the pressure for the flow in progress Reduction of the torque necessary for maintaining the pressure above 125 Nm for 2 seconds Conditions of activation of the diagnostics: Engine hot, running between 1750 and 4500 rpm with strong injected flow
Conditions for Fault to clear:	Driving with the engine hot for 5 minutes with several accelerations under full load for 10 seconds.
Downgrade Modes whilst Fault is active:	Deactivation of processing of the accelerometry Fuel flow regulator not controlled Deactivation of the accelerometry strategies Request for Delayed Engine Stop Deactivation cruise control until the next time the ignition is switched on Deactivation of the cruise control Deactivation speed limiter until the next time the ignition is switched on Deactivation of the speed limiter
Symptoms:	Engine hesitating, cutting out Lack of power Starting problem Diesel fuel consumption a bit higher Fluid leak/Smells Noise Engine acceleration at wrong time Smoke from the exhaust Engine overheating with illumination of the engine coolant temperature indicator light
Suspect Areas:	Fuel Diesel fuel filter Low pressure diesel circuit Fuel flow regulation valve high pressure fuel pump Fuel high pressure common injection rail pressure sensor High-pressure fuel pipe Fuel high pressure common injection rail Fuel injectors Camshafts Engine ECU Engine fusebox Connectors Electrical harnesses

Fault Code:	P1671
Description of Fault:	Cruise control: Reference speed outside the tolerance.
Conditions for Fault to clear:	Ignition on
Downgrade Modes whilst Fault is active:	-
Symptoms:	-
Suspect Areas:	-

[mihkel]

This was the longest wait for an aftermarket spare part - two and a half months.... I wanted to order Delphi 9109-927 but this could not be delivered so in the end they gave me part with a newer code 9109-936.

Works fine with the new part, did multiple WOT pulls to see if the fault persists - no limp mode! Was happy already that this has fixed the car. Gave the car to the wife and a day later she said that the fault occurred again.

So the solenoid has not fixed the problem, but low and high pressure fault have not occurred in 200kms (P0088 and P0087). The only faults are P0094 and P1671, the last one is caused by the first fault.

So the next suspect would be the pressure sensor or the injectors. Fuel rail pressure is still fluctuating.
The injector correction also seems all over the place.

#1 injector correction at idle -56%
#2 injector correction at idle 103%
#3 injector correction at idle 2%
#4 injector correction at idle -49%

[Emuu51]

I discovered that one of the butterfly valves on the EGR system was not being activated as the arm had slopped off the actuator. This has over time caused a massive build up of crud under the cover that goes over the fuel injectors, plus has distorted the cover which now leaks. I need a new cover and gasket, but I can't find a part name or number for it. Can anyone help please?

[wurlycorner]

I need a new cover and gasket, but I can't find a part name or number for it. Can anyone help please?

There used to be a dedicated service for this on the forum, but unfortunately access to the Stellantis parts system has been lost at the moment.
Hopefully someone on the forum has the information and will be able to help, though.

EDIT: If this is your engine, it has been fitted to a lot more manufacturer vehicles - you may find it easier to match the parts out there in Australia by looking at those?
FURTHER EDIT: also this is a complete stab in the dark from me, not knowing your exact vehicle but going off the general one mentioned in this thread... If this is the right EGR valve then the cross-compatibility part numbers (scroll down a bit and it lists all the manufacturer oem numbers) should also hopefully help you track down the information you want, out there? https://www.autodoc.co.uk/hella/12769432