Anti-Theft - Perimeter

Anti-Theft

Principles of Operation

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

The SJB (Smart Junction Box) controls the operation of the perimeter alarm based on inputs received over the Medium Speed Controller Area Network (MS-CAN) from the Driver Door Module (DDM) and the Remote Function Actuator (RFA) module. If the SJB (Smart Junction Box) receives an input indicating an unauthorized entry into the vehicle, the SJB (Smart Junction Box) activates the perimeter alarm by sounding the horn and flashing the turn signals in regular intervals.

The DDM (Driver Door Module) receives hardwired inputs from the driver door lock control switch and the door disarm switch (part of the driver door latch). The DDM (Driver Door Module) then broadcasts the status of these 2 switches over the MS-CAN (Medium Speed Controller Area Network) to the RFA (Remote Function Actuator) module and the SJB (Smart Junction Box).

The RFA (Remote Function Actuator) module receives hardwired inputs from the passenger door lock control switch, hood switch, all door ajar switches, and the liftgate ajar input from the Liftgate/Trunk Module (LTM) and the keyless entry keypad. The RFA (Remote Function Actuator) module also receives wireless signals from the Intelligent Access (IA) key for the operation of the IA (Intelligent Access) feature and Remote Keyless Entry (RKE). The RFA (Remote Function Actuator) module then broadcast the status of these inputs over the MS-CAN (Medium Speed Controller Area Network) to the SJB (Smart Junction Box).

Once the SJB (Smart Junction Box) receives the inputs from the DDM (Driver Door Module) and RFA (Remote Function Actuator) module, it either activates, deactivates, or triggers the perimeter alarm.

Alarm Event PIDs

The RFA (Remote Function Actuator) module and SJB (Smart Junction Box) both have PIDs available that show what caused the last alarm events. The SJB (Smart Junction Box) has 4 alarm event PIDs and are AL_EVT1 thru 4, and the RFA (Remote Function Actuator) module has 8 alarm event PIDs 1 thru 8_Alrm_Trg. The most recent alarm event is always listed in the first alarm event or trigger PID. These PIDs display what caused the alarm to trigger and can be a very useful tool when trying to identify the cause of an alarm trigger.