Long ago my 2003 GMC Envoy wound up stuck in 4LO randomly. The selector was set to 2HI but you could tell it was 4LO. The Transfer case motor was trying to switch ranges but was audibly struggling as if it was locked up. Long story short, I pulled the motor off and manually adjusted the splines...
Does anyone know exactly where the TCCM is located...I know it's
under the dash by steering column. My Envoy 4wd switch has no light.
Dealer says TCCM has failed. Have replacement ready to go in, but
could not locate old one under dash. What gives?