I am having 4 wheel drive trouble with my 2000 Silverado 1500. I have searched numerous forums for this and have had no luck. My pickup has the service 4 wheel drive light on and does not engage. It has no lights on the switch until you press the buttons. And the only one that will stay on when pressed is the auto 4 wheel drive light. This is a list of things I have tried. Checked and replaced all the fuses,
Replaced the 4 wheel drive dash switch, cleaned the frame ground and soldered a new wire and connector on the ground below the drivers door. Replaced the actuator on the front differential. I jacked the vehicle up and the front differential is locked in, and the transfer case seems to also be engaged, with the front axle jacked up and the rest tires on the ground I cannot turn the front drive shaft. But it doesn't spin the front wheels when you are in mud or snow. It has me confused. Anyone have similar symptoms? Next step will be is either the transfer case module or the transfer case.

 

the transfer case control module will have codes but it must be read with a full function scan tool...cheap code readers only access powertrain codes.

does the front driveshaft turn when driving in auto 4wd or is it stationary when the driving?

iirc in auto4wd the front axles are locked but the tcase is only engaged by a clutch pack when wheel slip is detected. some one correct me if i am wrong.

 

Thank you for the response. There are no codes. I have ran the codes at the Chevy dealership and there were none. The strange thing is it acts like it is in 4 wheel drive with the vehicle in the off position also. The drive shaft will not turn by hand with the front differential jacked up and the key off. Rear wheels still on the ground. Any other suggestions would be greatly appreciated.

 

Yeah.

I hope that you don't allow all four tires on the ground to do this. If everything engaged, you could have a moving vehicle, and that's not a hospital stay I'd take a chance on.

 

maybe you have a weak encoder motor

 

Will the weak encoder motor cause the service 4 wheel drive light come on? Thank you for the help.

 

if the service 4wd message is present...you have codes.