My fuel Gauge is not resetting after I fill.
It doesn't immediately react to the fuel I put in,
Well not for about a half an hour driving..

Now my fuel light won't go off and the tank is half full!!
The dealership said to remove the keys when filling the tank but that hasn't solved anything plus my other car is an 03 S40 with the switchblade key (Dealership said they have had these problems with those keys) and I haven't experienced this with that car.

New fuel gauge?

Or a sending unit, which is located in the tank.

I can't see how it would be the key. I've filled it with it runnig, and never had an issue. I'm gonna go with jks2.

I can't really see it being the sender unit either - I can see how the sender could posibly be slow to react to the fuel going in, but if it is registering half a tank then surely its getting a signal to the guage (but the light shouldn't be on with half a tank!)

What with everything on these cars being wired and connected to the cars computer, could it not be a software fault ?

software is my guess also...

I k now that on my 850's they both won't register any amount in the tank unless I shut off the ignition first. Otherwise I will just drive around at the last amount that was in there until it hits empty then it will go up to where the fuel level is. It's weird but hey, at least it works and makes the wife think we are about to run out of gas. :57:

Hi, greetings from a mew member and the proud owner of a 150.000 plus mileage v40! However, on a recent trip the fuel guage died on me while traveling along a motorway - one minute half full, next minute empty and the warning light on!! The tank is now full but the lights are still on!! Can't seem to fix it!

You may need to pull or replace the Fuel Dipper in the Tank, use the opportunity to clean the tank too.