Vehicle: 2012 Chevy Tahoe, 4WD, V8-5.3L, automatic transmission/transaxle
Mileage: 134,569
Problem: This vehicle came into the shop because there was no power window operation at any door. The lock-out switch was not set to “lock”.
Case details: The technician looked at the wiring diagram and was puzzled. How could all the windows be inoperative when each window has separate power, grounds and switches? Nothing was shared. Even the circuit breakers were separate on the driver and passenger sides. All fuses and circuit breakers were fine and there were no diagnostic trouble codes (DTCs).
An ALLDATA Tech-Assist consultant noted that the common things shared by all windows were the General Motors local area network (GMLAN) and the window lock-out circuit. Since there were no GMLAN DTCs, he advised checking the body control module (BCM) for a window lockout issue.
He also advised testing the power and ground for the driver master switch because both are necessary for the logic circuits to work properly.
The technician removed the driver switch and began testing. He found the switch assembly was burned and melted. All windows were in lockout mode and the driver side didn't work because of the melted switch.
Confirmed repair: He replaced the pigtail connector and the driver side switch. After the repairs, all the windows worked perfectly. Problem solved!
Reprinted with permission from ALLDATA.
