Theory Of Operation

The Body Control Module (BCM) provides a reference voltage on the Door Ajar Switch Sense circuits to the Passenger and Rear Sliding Door Ajar Switches (integral to the Door Latches). A ground is provided to the Door Ajar Switches through the wiring harness to the body sheet metal.

The Door Ajar Switches are normally open when the Doors are closed. When a Door is opened, the related Door Ajar Switch closes and the BCM detects the reference voltage on the Door Ajar Switch Sense circuit is pulled low.