Citroen C5 Aircross 1.5HDI P0087 Low Fuel Pressure

[Midship2]

Hello all

I recently bought a 2020 C5 Aircross to replace my VW. The car sat for a month or so before I bought it I believe. Whilst taking the roadtrip back home, at 6-7th gear, 2-3k rpm, If I were to go full throttle, the dash will light up with engine fault, transmission fault and electric fault and car goes into limp mode and it locks the transmission to the gear, and limits the power. After I pull over and restart the car, only the check engine light persists (P0087 Low Fuel Pressure). This only happens at highway speeds (90-120KM/H) , with more than %20-30 ish throttle. After I restart the car, despite the fault, car doesn't bog down, or has any issues with acceleration (up until I go a bit fast and then limp mode again), or has any trouble starting. It doesn't do it If I simply do full throttle going 40-50KM/H at lower gears.
Stuff I have done:
Replace fuel filter housing and fuel filter (Housing had sediment buildup, my mech said it'd be best to replace it)
Oil Change and other filters
Replace fuel pressure sensor at the end of the fuel rail
Clear codes with a cheap OBD2 thing

I threw the cheap easy to get to parts at it, hoping it would fix it but it didn't. Before I start throwing the more expensive parts at it, I'd like some guidance.

Also when the dash lights up, very rarely a transmission fault code pops up but then goes away after I restart. I'm assuming the limp mode causes this (as it locks the transmission), but I'll also write the code for that after I find the paper I wrote it down on.

[Midship2]

The code is U1209 for the transmission, but it doesn't persist and it doesn't throw the code every time.

[Midship2]

Took the bullet, went to the Citroen service, they basically said they have no idea what the problem is and they'd just throw parts at it and it could come up to €10000 if they have to replace the entirety of the fuel system.

After this I just took it to a PSA specialist instead, he tested the injectors and a pair of them were on their way out, so he recommended 4 injectors and a battery (battery was very low too), that seems to have fixed the problem so far.


Also never do pre purchase inspections with chain stores, I don't think I've ever read a paper this inaccurate and full of errors. According to the paper, "clutch" is on it's way out on a car with a torque converter, and supposedly the timing chain and belt are on their way out, on a car that's already JUST had the 8mm kit fitted.
They also failed to mention this error, which apparently had been an issue with this car before I bought it, and not a strange gremlin that suddenly appeared as soon as I bought it. (as the dealer claims)

[Mark77]

Hi,
I have the exact same fault with my car.
What mileage was your car in when it faulted and who did you use to fix your car I am really struggling to find someone to fix my car.
Thanks,
Mark

[Midship2]

Hi,
I have the exact same fault with my car.
What mileage was your car in when it faulted and who did you use to fix your car I am really struggling to find someone to fix my car.
Thanks,
Mark

Around 135000 kilometers (83k miles). I went to a local PSA specialist I know. We checked out the injectors and they were just pissing oil. Either someone ran a ton of injector cleaner through the engine, to get rid of the injector fault, or they reused the injector seals after doing the 8mm chain upgrade, but that upgrade was done in Citroen so I dont think that's the case.

Sadly on the part with finding someone to fix your car, I don't think I can help, as I reside in Turkey. So either stick to Citroen service, or find a specialist that works on diesel PSAs.

[Mark77]

Thanks for the feedback. My car has done 38000 miles last owner had one injector replaced when two years old under warranty. So probably is the injectors. Thanks Mark

[Midship2]

Before you do go for the injectors, get your battery checked. Mine was very low, low enough that star stop wouldn't engage, and I still suspect that might have played a part in the problem.

[Mark77]

Thanks for the reply.
Mine has had a new battery fitted.
Since fitting and setting up my Start Stop has been working fine.
If you keep car lower than 2000 rpm the car drives fine, mine is a manual, as soon as you go over this to overtake etc it faults with the low fuel pressure fault code, trying some fuel additive to see if that makes any difference.
On changing the fuel filter. The base of the filter was a creamy white mess. Not sure if this is part of the problem?
Thank you for the feedback and advice.
Mark

[Mark77]

Forgot to mention, the last owner fitted the incorrect battery. It was a non-stop start battery. I fitted it with the correct battery.

[Mark77]

White yellow mess in the fuel filter was probably water. On Closer look it was round the water drain plug on the bottom of the filter housing.

[Midship2]

Thanks for the reply.
Mine has had a new battery fitted.
Since fitting and setting up my Start Stop has been working fine.
If you keep car lower than 2000 rpm the car drives fine, mine is a manual, as soon as you go over this to overtake etc it faults with the low fuel pressure fault code, trying some fuel additive to see if that makes any difference.
On changing the fuel filter. The base of the filter was a creamy white mess. Not sure if this is part of the problem?
Thank you for the feedback and advice.
Mark

Mine only did it under load, and very occasionally, so much so that I drove about a hundred kilometers once without the error coming up. If yours do it consistently during similiar conditions, I would suspect the fuel pressure sensor. You could try cleaning it with some contact cleaner or just replace it as its only like a 30 euro part. Though getting to it is a bit of a pain, as its located at the end of the fuel rail, under all the air filter piping and stuff.

[Midship2]

White yellow mess in the fuel filter was probably water. On Closer look it was round the water drain plug on the bottom of the filter housing.

Yeah mine was like that too, we noticed whilst changing the filter. We changed the housing in case there was a blockage we didn't see but it didn't really change anything, but try to clean it just in case.