Oh dear... A buffet of horrible codes.... can anyone give me any advice please?

[c16rkc]

So my pesky C5 X7 is at it... again...!

This time I had it cut out on me, which had me wondering if the fuel filter needed doing... so I ordered one at the weekend.

But then today, on the way to work, it spluttered and cut out on a roundabout. When I restarted it (while moving) I got a "Depollution system faulty" message, and the engine management light has pinged itself on.

So tonight I let Dogbox do it's thing... and I got so many codes I don't know what to do with them all

I have now got:

• A4C5 - Brake light (OK this is unrelated, my 3rd brake light is indeed out... like most C5 X7 estates...).

• F5FF - Unexpected re-initialisation fault coming from the BSi

• F997 - Engine fusebox - Fault in the horn control circuit

• FF14 - Windscreen wiper motor Slave motor operating fault (This fault has been present for months, and will not stay reset, but both motors are brand new and working fine)

• P0087 - Fuel pressure regulator control

• P0088 - Fuel pressure regulator control

• P2084 - Catalytic convertor downstream temperature signal

• P0215 - Injection system supply relay circuit (1 stage)

• P1671 - Cuise control (this fault has been present since I got the car... but the cruise does work)

• P0495 - Fan assembly circuit

• P1351 - Preheating relay circuit

The car drove fine all the way home (40 miles) but it cut out once at a junction, so it seems to do it's cutting out when coming to a slow, then re-accelerating.

I am thinking start with replacing the exhaust temp sensor... but before I do....

Has anyone ever seen something like this before?

[Hell Razor5543]

I do know the error you can safely ignore (until you decide it bugs you) is P1351. It seems that almost all HDi engines throw up this error, and they soldier on regardless.

[c16rkc]

Well that's one out the way

[RichardW]

Clear all the codes, see if any come back straight away, then drive it and see which come back. I'd be thinking the fuel pressure reg codes are the likely pointer. Some of these 2.0 engines have a tendency for the GP pump to die.

[Rp0thejester]

P1671, cruise control issue. I had that before the MAF went completely doolally. Worth a look. All those P codes seem to relate to fuel and air issues

[c16rkc]

OK sounds like a plan - so I'll do exactly as above...

[c16rkc]

So... bit confusing...

I turned engine off, ignition in, and reset those ignition related codes.

Restarted car, and the codes stayed off...

Took the C5 down the road, it drove perfectly. Then nearing my house I decided to accelerate harder than I normally would.

Under acceleration, I could feel it struggling, like it could not get enough fuel... tried again, same thing but this time the Depollution fault came back on, along with the engine management.

Got home, plugged in Dogbox.

None of the previous codes are present... but now I have:

• P0094 - Fuel system

(ignoring P1671 and P1351 which are present too...)

So perhaps it is the fuel filter?

I have reset again, and will try again tomorrow...

[GiveMeABreak]

I'm sure glad most of those went - saved me a lot of time!

As Richard mentioned above, the fuel regulation seems the issue. Fault descriptor against your specific engine and Engine ECU below:

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 Switching on of the warning lamp and/or warning message: Warning lamp MIL
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

[Rp0thejester]

So basically Citroen don't know, just try everything... Your C5 engine bay is alot easier to work on than my C8. Lack of power uphill, I'd say MAF cheap fix, EGR issue, just some spray to clear it. But lack of power AND emissions warning says it MAF to me. Once I replaced my MAF no more DPF warnings. Just my opinion though...

[Armidillo]

Do these cars have an in-tank strainer on the fuel intake? If it genuinely is starving for fuel and it's not the fuel filter, then definitely worth checking the strainer (if fitted).

[c16rkc]

Oh my goodness that is a comical list - thanks for posting Mark!

I think I'll start by changing the fuel filter and MAF - can't hurt to change those out, and at least it's something else I have my own datum for. I may replace the battery too, as there is no indication in the history how old it is.

I'll also scan codes again tonight, to see if there is any change.

[Hell Razor5543]

If you have not already done so (and if there is one in your area) try signing up to the GSF newsletter. It can result in discounts of (up to) 65%.

[c16rkc]

Thanks James - yes I did that a while back; I think it was on your recommendation not long after I signed up to the forum.

I am very fickle though, usually search everywhere I can when I need parts

[Sloppysod]

....... I am very fickle though, usually search everywhere I can when I need parts

Like that one, I always say "I'm tight" when it homes to getting the best price for the quality of item I need.

[RichardW]

I would just change the fuel filter first; when that gets a bit blocked it gives the symptoms you are seeing. Since there is no MAF code I wouldn't touch it for now.