C5 X7 Fuel Pressure too high

[steveclv]

I'm currently on my trip to the UK and the car has behaved impeccably so far - however today, after accelerating hard to overtake a lorry, I got the engine warning light and a "Pollution System Fault" error message. I plugged in Diagbox and got the fault that said "Fuel Pressure too high" which didn't seem to be related to Pollution but was the only fault. So I cleared it and then went for a drive - starting hard from a standstill to 60mph did not cause a fault but a hard pull from D4 did recreate it.
Is this possibly a faulty fuel pressure sensor or is there anything else that can create the problem - fuel pressure regulator? high pressure pump?

When the engine lights up it doesn't seem to affect drivability at all.

[GiveMeABreak]

Do you have the specific fault code Steve?

[steveclv]

P0088?

[steveclv]

This has been an ongoing issues but seems to be getting slightly worse. The diag mentions Fuel Pressure Regulator as well as the pump - do you have any idea where the regulator is located as well as the sensor? If they are (a) cheap enough and (b) accessible, then I may try just changing them before tackling the HP pump

[GiveMeABreak]

Here's the fault descriptor if it helps.

Fault Code:	P0088
Description of Fault:	High pressure fuel regulation: The measured rail pressure is too high in relation to the set point. Description of the diagnostics: 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

[steveclv]

Thanks - it has a new fuel filter and I just ran a tank full of engine/injector cleaner through it. Can't think that it's electrical as the car is corrosion free so it's down to the fuel pump or sensor - do you have a part number for the pressure sensor if you have a spare minute or two please? Thanks!

[GiveMeABreak]

The fuel pressure sensor is not available separately on the parts database Steve, it comes as a complete unit, often due to issues with these if separated so they are fixed at factory on this engine.

(2) Injector Supply Rail, part: 1570L9, £366.18

and if this has to be replaced I hesitate to add that the injection Outlet pipes (3) & (4) should also be replaced as they are designed to seal when tightened by deforming slightly and if later removed and refitted, they often won't seal properly. That's the official line anyway.

[steveclv]

Thanks!
Time for a rethink

[steveclv]

Marc

Do you have the part numbers for (3) and (4) please as I have located a brand new PSA 1570L9 for €80

Thanks!

[GiveMeABreak]

(3) Injection Pump Outlet Pipe (for 1 & 2), part: 1570N0, £56.52
(4) Injection Pump Outlet Pipe (for 3 & 4), part: 1570N1, £56.11