Hi everyone I have a 2009 GMC sierra 2500 HD 6.0 and having issues with the 4 wheel drive..on start up the service 4 wheel drive message comes up. The 2 wheel drive light is lite on the dial and it is in 2 wheel..when put in 4 wheel high or low it does nothing no lights nothing. I changed the axle actuator and the switch still nothing..I pulled the trec fuse and waited to reset and nothing. could it be the tccm or the transfer case motor? Is the anyway to test them? I have power going to everything. I read if it was the case motor it would make a noise like its trying to go in but wont.. I get no noise no lights or anything.. Any help please as I really don't know where to go from here.. thank you