Principles of Operation (How Does it Work?)

The Door Switch Lock Function
When a door lock switch is moved into the lock position or a door lock cylinder is rotated to the lock position, the door lock switch grounds the lock circuit input to the Generic Electronic Module (GEM). The GEM then provides 12 volts to one side of the door lock actuators contained in the door latch unit and simultaneously grounds the other side of the door lock actuators. This completes the door lock actuator circuit, causing the door lock actuators to rotate a cam assembly, which then locks the doors.

The Door Switch Unlock Function
When a door lock switch is moved into the unlock position, the door lock switch grounds the unlock circuit input to the GEM. The GEM then provides 12 volts to the opposite side (relative to locking the door) of the door lock actuator(s) contained in the door latch unit and simultaneously grounds the other side of the door lock actuator(s). This completes the door lock actuator circuit, causing the door lock actuator(s) to rotate a cam assembly in the opposite direction, which then unlocks the door(s). The 12 volts which the GEM provides to the door lock actuator(s) are provided to each door lock actuator from the individual pins on the GEM connector.

The Liftgate Release
When the liftgate release switch is depressed, it grounds an input circuit to the GEM. When the GEM senses the ground, it sends 12 volts to cycle the liftgate release actuator.

Door Lock Cylinder Functions
Both the driver and passenger doors can be locked from either door lock cylinder. When the ignition key is inserted into either door lock and is rotated into the lock position, the linkage moves to rotate a cam in the door latch unit. When the cam in the door latch rotates, it mechanically moves the door latch (in the door in which the key is being used) into the locked position. The other doors are locked electronically.