S40 Dodgy Fuel Gauge

[cje205]

Hi

I've got a 2010 S40 D4 R-Design saloon.

Been having problems with it recently. First thing that happened was the clutch inhibitor switch going and couldnt start it. That was replaced. A week after the fuel gauge started playing up. When filling up it would only go halfway (when it was actually full). And would slowly make its way to full or theee quarters. It somehow always shows less than what's actually in it. And when driving say 20 miles down the road it will say you've gone through half a tank.

The local garage replaced the fuel sender unit. But to no avail. Some days it looked like it was better, then other it was not. Local volvo dealer looked at it- no fault codes and that was that.

This past week and a half it has behaved normally. Going to full on a fill up etc and behaving normally since.

Until today. The one variable that's changed is that I've put my rear seats down to carry my bike. And this is something that I use to do a lot.

A very stupid question- but could the rear seats be causing my fuel gauge problems? From what I've googled, the access to the fuel pump is somewhere in the trunk/rear seat area?

[v70stu]

Ah, dealers, bless em. No fault codes so no problem. That's about as far as most seem to be capable of going these days. Pet hate of mine.

It sounds like there could be a correlation between dropping the seats and the fuel gauge issue. I'd take a look at the wiring to and from the sender unit in the area under the rear seat as a starting point?

[volvo for ever]

id remove tank unit very easy wasbad for wires breaking....

[paddyred]

Originally Posted by volvo for ever

id remove tank unit very easy wasbad for wires breaking....

+1 for checking wires. Its unlikely to be the guage but I guess its a possibility. I hate main dealers for that exact reason. Fault codes help find a fault, not tell you if it anything is broken