Grand Cherokee 4WD V8-4.7L VIN N (2000)
Door Sensor/Switch (For Alarm): Description and Operation
The door ajar switches are concealed within and integral to the door latch units. The front door ajar switches are actuated by the front door latch
mechanisms, and are hard wired between a body ground and the Driver Door Module (DDM) or the Passenger Door Module (PDM) through the front
door wire harnesses. The rear door ajar switches are actuated by the rear door latch mechanisms, and are hard wired between a body ground and the
Body Control Module (BCM) through the rear door and body wire harnesses.
The door ajar switches cannot be adjusted or repaired and, if faulty or damaged, the door latch unit must be replaced.
The front door ajar switches close a path to ground for the DDM or the PDM when a front door is opened, and opens the ground path when a front door
is closed. The rear door ajar switches close a path to ground for the BCM when a rear door is opened, and opens the ground path when a rear door is
closed. The DDM, PDM, or BCM reads the switch status through an internal pull-up, then sends the proper switch status messages to other electronic
modules over the Programmable Communications Interface (PCI) data bus network. The door ajar switch status message is used by the BCM as an input
for Vehicle Theft Security System (VTSS) operation.