Grand Cherokee 2WD V8-4.7L VIN J (2004)
Lock Cylinder Switch: Description and Operation
Fig.1 Door Cylinder Lock Switch
DOOR CYLINDER LOCK SWITCH
Vehicles manufactured for North American markets that are equipped with the optional Vehicle Theft Security System (VTSS) have a door cylinder
lock switch secured to the back of the key lock cylinder inside the drivers front door. The door cylinder lock switch is a resistor multiplexed
momentary switch that is hard wired in series between the door lock switch ground and right or left cylinder lock switch mux circuits of the Drivers
Door Module (DDM) through the front door wire harness. The door cylinder lock switches are driven by the key lock cylinders and contain two
internal resistors. One resistor value is used for the Lock position, and one for the Unlock position.
The driver cylinder lock switch cannot be adjusted or repaired and, if faulty or damaged, the driver side front door lock cylinder unit must be replaced.
Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further
details on wire harness routing and retention, as well as pinout and location views for the various wire harness connectors, splices and grounds.
The driver cylinder lock switch is actuated by the key lock cylinder when the key is inserted in the lock cylinder and turned to the unlock position. The
driver cylinder lock switch maintains a path to ground and changes voltages through an internal resistor for the DDM when the driver door key lock
cylinder is in the lock or unlock position. The DDM 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 driver cylinder lock switch unlock status
message is used by the BCM as an input for Vehicle Theft Security System (VTSS) operation and interior lighting.
The door cylinder lock switches and circuits can be diagnosed using conventional diagnostic tools and methods.
