Driver Door Unlock Operation
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. 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 driver door lock actuator unlock control circuit to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the driver door lock actuator transitions to the Unlock position.
The driver door lock actuator unlock control circuit is a dedicated control circuit used only for the driver door lock actuator. This is done so that the driver door may be unlocked individually before unlocking the passenger doors using a keyless entry transmitter or an automatic door unlock function, if programmed.