Floating gas gauge

[NashvilleMan243]

Ok, I bought a 2005 silver Bonneville GXP. I like the car. Its a very unique ride. I love the handling, for such a big car. But there's a problem. The gas gauge doesn't read accurately, it floats a lot, saying full when it has a quarter tank. The dealer put a sending unit in it. Still does it. What to do? My 2000 Grand Prix GT does this too. Any and all info will be appreciated.

[RJolly87]

Likely a bad stepper motor in the gauge cluster, especially if the sender unit didn't resolve it.

[NashvilleMan243]

Thanks a lot. I don't think the dealer put a sending unit in the thing. Now to find some GXP floor mats for it.

[RJolly87]

I forget, does the GXP have the fuel info in the DIC? Like fuel mileage, Distance to empty, etc? If so, that will give you another point of information to diagnose with. If the gauge and DIC consistently agree, and you know they are both wrong, the sender is likely to blame. If the fuel gauge just has a complete mind of it's own, it may be the stepper motor in the cluster.

[NashvilleMan243]

Yes, it does.

[nos4blood70]

If the fuel range remains consistent and the gauge moves around, then you should either get the cluster rebuilt or find a used GXP one. Personally I would get a rebuild on the cluster because the GXP clusters like to go a little wonky!

[NashvilleMan243]

Great!!