We finally had a big-enough snow this year to bring out the people with 4WD problems. This one was a 2008 Chevy Silverado 2500 HD.
It was from a tire distributor that has a number of these particular trucks. Their technicians had been trying to fix the issue of having no 4WD by putting various parts on it. They said that they had replaced the transfer-case motor and buttons.
I started out with the usual road test, scan and lift check to verify the problem. Sure enough, there was no 4WD and the transfer-case control module (TCCM) had every code possible stored. I thought I’d clear the codes and start out fresh.