GM Service Manual Online
For 1990-2009 cars only

Voltage is supplied to the door lock switches on CKT 2140 (ORN) from the mir/lock fuse. When the switch is depressed in the lock position, voltage is supplied to the lock relay on CKT 195 (LT BLU) in order to energizer the relay. Upon energizing the relay, voltage is supplied to the door lock actuators through the relay from the dr lock fuse. Ground is supplied through the unlock relay.

When the switch is depressed in the unlock position, voltage is supplied to the body control module (BCM) on CKT 194 (WHT), in order to energizer the relay the BCM supplies a ground on CKT 1391 (LT GRN). Upon energizing the relay, voltage is supplied to the door lock actuators through the relay from the dr lock fuse. Ground is supplied through the lock relay.

The BCM can also control the door lock and unlock relay based on inputs from the power door lock switches, vehicle speed (from the VCM/PCM over class 2 data bus), mini wedge (door jamb switches). The BCM will lock all doors when the vehicle reaches a speed of approx. 15 miles per hour. On vehicles equipped with RKE, the BCM locks or unlocks the doors base on the command received from the remote control door lock receiver on CKT 461 (ORN).