Circuit Description
WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. 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 message from the Powertrain Control Module (PCM) requesting to illuminate the backup lamps, battery voltage is sent directly from the BCM through the backup lamp supply voltage circuit to the backup lamps.