Grand Cherokee 4WD V8-4.7L VIN N (2000)
Seat Belt Buckle Switch: Description and Operation
DRIVER SEAT BELT SWITCH
The driver seat belt switch is concealed within and integral to the driver seat belt buckle-half unit. The driver seat belt switch is actuated by the
seat belt buckle mechanism, and is hard wired between a body ground and the Body Control Module (BCM) through the left body wire harness
with manual seats, or through the driver side power seat and left body wire harnesses with power seats.
The driver seat belt switch cannot be adjusted or repaired and, if faulty or damaged, the entire driver seat belt buckle-half unit must be replaced.
The driver seat belt switch closes a path to ground for the BCM when the tip-half of the driver seat belt is not fastened to the buckle-half, and
opens the ground path when the two halves of the seat belt are fastened. The BCM monitors the driver seat belt 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 driver seat belt switch status is also used by the BCM as an input for chime warning system operation.
