Hey everyone,

I need help with a 2003 GMC Sierra 2500hd with a 6.0l & 4l80e. I just bought the truck recently and the speedo seems to hang around 40mph and I'm getting weird shift points in the tranny along with auto volume control on the bose radio goes crazy with the volume. Does anyone have an ideas? So far no codes and I changed the vss out. I'm getting around 10mpg is that normal for this truck?

Thanks,

Scott

 

check the VSSs. Something's definitely screwy.

 

Is it 4wd? If so there is a connector for the vss right above the trans, between the t-case and trans. The wires always pull out of the connector, but you have to pull the conduit off to see it. Wires are purple and green I think. Ive seen it a handfull of times.

 

With the radio and the VSS issue you may want to check all grounds battery to engine and battery to chasis would be first place to look .

 

Thanks for the replies It's 2wd. I changed the vss out already. I'll go through and check all the grounds.