Fuel pressure too low

[1981George]

Hello,
I have a fairly regular issue with my 2004 XC70 2.4 D5. When accelerating up hill the 'ENGINE SERVICE REQUIRED' message will appear and it will go into limp mode. The engine light doesn't come on though.
I suspected a fuel pump issue and when I checked the code I get 2503
"State: None
Fuel Pressure. Pressure too low."
I've had an intermittant 'ENGINE SERVICE REQUIRED' message come and go for about 2 years now without being able to find the cause.

I've moved house recently and when I'm joining the dual carriageway I have to go up a ramp rather than down a ramp so it happens more frequently and I can trace it to this type of driving.

What would be the steps in trying to cure it? I think changing the fuel filter as it's simplest but probably won't cure it. After that would it be the fuel pump? Or clean/replace the injectors? Something else? What would be the best way to find the issue?

I've looked at changing the fuel pump. It looks reasonably simple but time consuming due to taking the rear seats out.

Any advice would be appreciated.

[Onewheel]

First start with changing the fuel filter, cheapest and easiest thing to do…
Clogged fuel filter because of bacteria grow because of the percentage bio-diesel in the diesel…

[Lancee]

Fuel filter first.

[Roy V70 850]

I had a similar problem. As soon as I accelerated hard uphill, the car went into limp mode with fuel pressure too low message on the icarsoft reader.

I changed the filter, the high pressure pump + ctrl valve. Was about to change the whole fuel rail when I talked to a Volvo specialist where he convinced me that it was most likely to be an injector fault. I took it in and they did a leakback test where this was confirmed. Injector 1 was replaced with an equivalent and everything was ok again.

I'm not saying this is the what is happening in your case, but its worth bearing in mind. CheshireD5 has a video on performing a leakback test if your so inclined.

It cost me £150 to have it fixed using a second hand injector.

[1981George]

Hi everyone, thanks for the advice. I'll change the fuel filter and if that doesn't cure it I'll take it to a local independant to see what he thinks.

[XC70Bob]

I would have a listen to the 2 fuel pumps on the end of the cam shaft there is a low pressure and high pressure one see if there are any strange noises.

Had my low pressure one seize breaking the drive between the 2 just before Christmas, does not return any DTCs about the pump only a low fuel pressure one.

Both are replaced as an assembly £500 bill and that was from an independent specialist..

[amorlv70]

I had pretty similar symtoms to you, except also had fluctuating fuel pressure and a bit of a rough idle at cold. Replaced filter, no change.
Replaced the fuel pressure sensor and this fixed the random 'engine service required' and rough idle, however after this the car started getting 'fuel pressure too low' and randomly dying (100% power loss) when pulling away.
I replaced the high pressure pump (the one in the engine bay) the other day and it now idles far smoother, and hasn't cut out since. As I say though this was only wednesday I replaced the pump, but it would usually happen on every journey.. Is there a way you can view your fuel pressure on a code reader?

The lift pump is a possibility, I believe it only runs when it 'needs to' when driving, ie under load, so a car may be still able to operate with a weak in-tank pump

[1981George]

Originally Posted by amorlv70

I had pretty similar symtoms to you, except also had fluctuating fuel pressure and a bit of a rough idle at cold. Replaced filter, no change.
Replaced the fuel pressure sensor and this fixed the random 'engine service required' and rough idle, however after this the car started getting 'fuel pressure too low' and randomly dying (100% power loss) when pulling away.
I replaced the high pressure pump (the one in the engine bay) the other day and it now idles far smoother, and hasn't cut out since. As I say though this was only wednesday I replaced the pump, but it would usually happen on every journey.. Is there a way you can view your fuel pressure on a code reader?

The lift pump is a possibility, I believe it only runs when it 'needs to' when driving, ie under load, so a car may be still able to operate with a weak in-tank pump

That's a good shout about reading your pressure live. I've got a code reader that can do live readings, I'll plug it in to see what I get and then may try to do it under load.