Passenger Door Unlock Operation
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
When the BCM detects a transition of either of the door lock switches to the UNLOCK position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the passenger door lock actuator motors transition to the Unlock position.
The door lock actuator unlock control circuits are dedicated control circuits used only for the passenger door lock actuator motors. This is done so that the driver door may be unlocked separate from the passenger doors using a keyless entry transmitter or an automatic door unlock function (if programmed).