Circuit Description
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
When the body control module (BCM) receives a class 2 signal from the powertrain control module (PCM) or engine control module (ECM) indicating the gear selector is in the REVERSE position, the BCM applies positive voltage to the backup lamps supply voltage circuit. The backup lamps are grounded at G301 for the left backup lamp and G302 for the right backup lamp.