The rear door and hatch on my 2006 Yukon XL won't lock. All four passenger doors lock and unlock fine. There is no manual lock on the rear door, so it stays unlocked all of the time.
2006 Yukon XL rear door and hatch won't lock on 2006 GMC Yukon
I call up GMC and they said it's probably the lock actuator for the back hatch that is not functioning properly...
I have the same issue on a different vehicle. With door switch, all 4 doors lock but not thye rear hatch. The system thinks it is still open, so it won't lock it until it is shut. I get no info on the DIC about it, but I can't lock it. While the system thinks that hatch is open, I can't use the remotes.