Help with GMC 4x4 service light

[chadly]

My service 4 wheel light came on a week ago and turned back off. Nothing had changed and I played it off as a fluke. Tonight I went to leave and the truck was in 4 wheel low. Nobody put it that way. It just decided to start up in 4 low. I pushed all the other buttons trying to switch to 2 high but they would not work. I did quick google and found the 4 wheel drive switch is a common problem. I then google how to test it and found mine tested good. What else would cause this to happen? Transfer case shift motor? I’m at a loss.

Thanks

Chad

 

[novaderrik]

this is why 4X4 trucks should all have a shift lever for the transfer case in the floor.

 

[Daniel Jost]

bad switch 90% of the time. Go get a new one and be on with it.

,Dan

 

[Daniel Jost]

My dad's 05' had the wires to the T-case motor rub through in the insulation and short out causing the same problem. I didn't read the part where you said you tested it. Pull back the covering loom from the motor to the connector and take a look there.

Good luck, Dan

 

[chadly]

Thanks.

 

[aminga]

My 99 did that and it was the switch

 

[muzz]

We have lots of the later model gm trucks in our fleet and it's usually the encoder ring sensor on the transfer case motor. You can get the part separately from the motor. There was a programming update at one time but yours doesn't sound like that.