Problems with fuel pressure (?) when low on fuel
 

Hello,
I have a 2001 S80 with a diesel engine (2.4 type D5). Some time ago I started to experience very strange behavior.

When I am low on fuel (but not very low - it's still about 10 liters in fuel tank, computer shows that I can still go for 120-140 kilometers), my car starts losing power. I experience several short power drops in the span of about 5-10 minutes, then I get a message 'engine system service urgent', and ECM switches off the turbine and generally puts the car in the 'just drive to service' mode. In most cases turning off engine and turning it back on helps to get rid of those problems, and when I fill the tank up, everything is fine. Sometines, though, switching the engine off causes problems with starting it back again (I suspect it is when I'm really low on fuel - 7 liters left, or so).

I took my car to service several times, but they weren't able to figure out what's going on. Based on ECM fault codes they replaced fuel injectors (ouch! pricey!) and fuel filter - nothing helped.
Below are fault codes registered by ECM:

ECM-2505 Fuel Pressure - Too low pressure
ECM-2501 Fuel Pressure - Pressure too high

As they say, those codes occuring at the same time usually indicate faulty injectors. But not in my case :(

Any ideas? I'd love to get some help on that, it goes on for almost three months and I'm starting to really worry. And I don't want to pay for my service experimenting on my car.

Thanks!!

RE: Problems with fuel pressure (?) when low on fuel
 

I guess that if it runs like that only when you are running low on fuel, just ensure that you don't let it get that low. It could be a fuel pump issue or possibly a problem with the fuel cap not maintaning pressure properly.

tech will have some good suggestions for ya.

RE: Problems with fuel pressure (?) when low on fuel
 

Not really sure about the diesels because in the U.S. we don't have them.

But it almost sounds like one of the sending unit for the fuel gauge are bad.
There is 2 of them one on each side. So I think you might be running out of fuel.