Circuit Description
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The Body Control Module (BCM) internally grounds the door lock relay control circuit for the rear door lock relay when it receives a Class 2 message from the Driver Door Module (DDM), Passenger Door Module (PDM) or the Liftgate Module (LGM) with a keyless entry transmission. When the BCM grounds the door lock relay control circuit the rear door lock relay is energized and locks the rear doors.