Grand Cherokee 4WD V8-4.7L VIN N (2000)
Trunk/Liftgate Sensor/Switch (For Alarm): Description and Operation
LIFTGATE AJAR SWITCH
The two liftgate ajar switches are concealed within and integral to the two liftgate latch units in the lift- gate. The two liftgate ajar switches are
actuated by the liftgate latch mechanisms, and are hard wired in parallel with each other between a body ground and the Body Control Module
(BCM) through the liftgate and body wire harnesses.
The liftgate ajar switches cannot be adjusted or repaired and, if faulty or damaged, the liftgate latch unit must be replaced.
Each of the liftgate ajar switches can close a path to ground for the BCM when the liftgate is opened, and opens the ground path when the liftgate
is closed. The 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 liftgate ajar switch status message is used by the BCM as an input
for Vehicle Theft Security System (VTSS) operation.
LIFTGATE FLIP-UP GLASS AJAR SWITCH
The liftgate flip-up glass ajar switch is concealed within and integral to the liftgate flip-up glass latch unit in the liftgate. The liftgate flip-up glass
ajar switch is actuated by the liftgate flip-up glass latch mechanism, and is hard wired in series between a body ground, the Body Control Module
(BCM) and the rear wiper motor module through the liftgate and body wire harnesses.
The liftgate flip-up glass ajar switch cannot be adjusted or repaired and, if faulty or damaged, the liftgate flip-up glass latch unit must be replaced.
The liftgate flip-up glass ajar switch can close a path to ground for the BCM and the rear wiper motor module when the liftgate flip-up glass is
opened, and opens the ground path when the liftgate flip-up glass is closed. The rear wiper motor module uses the liftgate flip-up glass ajar switch
input to control the rear wiper operation, and will park the rear wiper blade if this input indicates that the lift- gate flip-up glass is ajar. The 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 liftgate flip-up glass ajar switch status message is used by the BCM as an
input for Vehicle Theft Security System (VTSS) operation.
