Hello all, I have a 2000 Silverado 1500 Z71 5.3L and I'm having an issue with. The "Service 4WD" light stays on. I bought a transfer case switch for it but that didn't fix the problem. I don't have any lights glowing on the switch, none of the buttons seem to work. The truck runs fine but can't switch into Auto, 4 Lo or 4 Hi. Had a friend hook it up to his GM scanner reader but it's not showing any error codes. I'm curious if I bought the Dorman 600-101 4x4 actuator from Autozone if that would fix my problem? I'm not sure if the actuator would solve the lights in the dash or not. I also heard that it might be the Transfer Case Control Module?? I looked in the area near the emergency brake but didn't see it. I did see the "CTTF" but that's not the TCCM is it? Don't want to keep throwing money out the window. I bought some transfer case fluid for it but haven't changed it yet? What else could it be?

 

Probably the solenoid on the transfer case. these are a common failure item. I had to replace one on my 2000 suburban

 

Yeah I'm gonna try the transfer case actuator on Saturday, just bought one from Advance Auto so I'll pick it up Friday afternoon. I hope this does it but if not I guess it'll be the transfer case control module and that looks like a tight squeeze. I'll let ya'll know how it goes...fingers crossed.

 

It usually is not an electronic problem. Replace the solenoid (actuator), my $ is that it's the fix. Iv'e had to replace that, and the switch, I read where you replaced the switch.

 

Yeah I replaced the switch in the dash....I'll post my result when installed.

 

Well I replaced the transfer case actuator but that didn't fix the problem, so I took it back to Advance Auto. Well the only other thing I can think that it might be is the (TCCM) Transfer Case Control Module. That looks like it might be a job taking the dash out and whatnot. I looked for it but didn't see it. I did see the CTTF, I'm guessing it above that?

 

If I remove the transfer case control module can I still drive the truck? Just curious.