Power Door Lock Actuator: Description and Operation

Fuse 4 applies battery voltage at all times to the automatic door lock control relay. By locking or unlocking the driver's door with either the key or the door lock knob, the automatic door lock switch provides a ground path for the automatic door lock control relay. It signals the automatic door lock control relay to lock or unlock the passenger door. The automatic door lock control relay locks or unlocks the passenger door by applying battery voltage and providing a ground to the automatic door lock motor in one direction to lock the passenger door and by providing a ground in the opposite direction to unlock the passenger door.

Locking or unlocking the passenger's door with either the key or the door lock knob will not lock or unlock the driver's door.