2005 gmc envoy oil gauge


#1

2005 gmc envoy sle When I fuel up my oil gauge goes up i.e. 1/4 tank = 42 on oil gauge 1/2 tank = 80 on oil gauge and fuel mpg goes down as oil goes up, any ideas as to a cause?


#2

Sounds like a cluster issue. A scan tool will be most helpful at this point to see if the data matches what the cluster shows. Data is fed to cluster via modules, whether it be BCM or PCM. If data agrees, try unplugging connector at alternator and see if it straightens out. I say alternator because it might have a problem causing it to put out AC voltage instead of DC voltage which car electronics are much happier with.


#3

Faulty ground connection to or in the cluster.