2001 2500HD issues

[01Plow]

So my '01 with 110K refuses to go into 4x4. The info centre says "service 4WD"...I think it's the selector switch? And my fuel gauge barely works...sending unit?
Any advice would be great...
(it has the 6 litre)

 

[Molson02536]

So my '01 with 110K refuses to go into 4x4. The info centre says "service 4WD"...I think it's the selector switch? And my fuel gauge barely works...sending unit?
Any advice would be great...
(it has the 6 litre)

Very common that the 4wd switch it self has gone bad and you can ether try cleaning the contacts first on it or you can replace it, but check the switch first with a multi tester first before you replace it.

The other area that is also common is the wire harness to the encoder motor on your transfer case may have gone bad from loose connection or corrosion, is would also be a good thing to address once you checked your 4wd switch.

Last would be the TCCM going bad or the encoder motor gone bad, but start with the electrical first before getting in to the more expensive repair like the TCCM and encoder motor replacement.

Good luck and keep us posted

 

[Z15]

I had a 2001 GMC Sierra SLT E. Cab Z71 and before the truck was a year old they had replaced the dash switch, the transfer case motor and some other electronic part under the dash. First the truck would not go into 4wd and then it would not come out.

Shoddy Delphi electronics were the blame for a lot of these problems and led to Delphi going bankrupt, infamous court battles with GM over these electronic issues.