2006 Sierra T/C Stuck in Neutral

[johnthecanuck]

My 2006 Sierra recently started giving me some trouble with the 4wd system. It was taking multiple attempts to get it to go into 4H and the service 4wd msg would display. After it did this for a period of time, it would not switch into 4H at all and only went into AWD and would not shift out of that. Did a bit of research online and decided it may be and issue with the encoder motor on the transfer case, so I went ahead and changed it out. I had to manually turn the shaft on the TC to get it to line up with the slot in the encoder motor but eventually it seemed to mount up properly. When I went to test it out, the selector switch automatically changed to neutral and now won't go into any gear at all. When I press 2H or 4H, I can hear the encoder motor engaging and the light will start flashing for a few seconds, but then it just changes back to neutral with the red light displaying. I disconnected the battery overnight and reconnected it the next day hoping the TCCM would reinitialize but it just did the same thing. Service 4wd light is also displaying. I removed the encoder motor again and reinstalled it, this changed nothing. I am thinking maybe I need to change out the TCCM? I am in over my head here. Any suggestions or help would be appreciated.

 

[98trck]

I have no experience with new transfercase systems, here is a thought
remove the encoder motor but leave it connected and select 2h then 4h,etc and what does the encoder motor do ?
so what is happening with the new encoder motor, is it completely different from the original problem?

 

[johnthecanuck]

If I test the encoder motor while disconnected from the T/C, I can hear it engaging but the shaft input part does not move, it stays in neutral. If I test the old one, it does the same except it stays in AWD as this is where it was when I removed it. I have now tried a new TCCM and selector switch but neither made any difference. I am thinking that maybe the new Dorman encoder motor I got was bad too? Not sure what else it could be?