GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hi and thank you for your question. My name is ***** ***** I'll do my best to help. You stated the vehicle will not move while turning, correct? And this occurred before and after you rebuilt the T/case?
are you still needing assistance?
the most common issues on the gm 4wd platform is the front differential actuator going bad. they unscrew from the differential. i would try removing the actuator and then seeing if you can turn and move. if you can the actuator is stuck in 4lo and will need to be replaced. note:: do not drive far just a very sort distance as removing the actuator will allow fluid to be able to spill and a small amount will come out when you removed the actuator.
give me a moment to find the best picture i can. you should be able to see it from underneath the front of the vehicle it is on top of the extension tube on the passenger side. has a square connector.
im finding conflicting pictures some show the spot for the actuator and some do not. do you have the production date for me?
ok well im going to go with it doesnt have the front diff actuator. if you have replaced the encoder motor and it still have the same issue i would be inspecting the transfer case control module or the switch itself. at the shop is the vehicle on a side by lift?
you can also try a reflash of the tccm per gm bulletin 09-04-21-001 and a clutch reset procedure with a scan tool. the scan tool will walk you through the reset procedure but the reflash will need to be done via either the dealer or a local mobile computer flashing service if there is one in the area.
there may be no code in the system the reflash is updated programming via gm. and the clutch reset procedure should be done anytime a t-case is rebuilt or the encoder motor is replaced.
ok sounds good.