GM Service Manual Online
For 1990-2009 cars only

The BCM receives a signal via Class II from the PCM indicating the position of the transaxle range switch. When you press the release button on the RKE transmitter, a signal is sent from the remote control door lock receiver through circuit 377 to the BCM. Then, the BCM sends a ground signal through circuit 253 to the rear compartment lid release relay. The relay receives power from the DOOR LOCKS fuse. When the relay receives the ground from the BCM, the relay's internal switch closes sending B+ (via circuit 56) to the rear compartment lid lock release actuator. A ground is always supplied to the actuator through circuit 350. When B+ is received at the actuator through circuit 56, the rear compartment lid releases.