Circuit/System Description

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The power sliding rear window motor is controlled from the sliding rear window switch through OPEN and CLOSE relays. The sliding rear window switch is supplied voltage from the body control module (BCM) accessory voltage output circuit. When the switch is pressed in the OPEN or CLOSE position, the sliding rear window open relay or the sliding rear window close relay coil will be supplied accessory voltage and energized through the appropriate relay control circuit. While the sliding rear window open relay or the sliding rear window close relay are in a de-energized state both motor control circuits will be closed to ground. When one of the relays is energized its motor control circuit will be closed to the battery voltage supply circuit and the other motor control circuit will remain grounded through the de-energized relay.