Anti-Theft - Perimeter

Anti-Theft

Principles of Operation

The Body Control Module (BCM) controls the operation of the perimeter alarm based on inputs from all of the door ajar switch inputs, hood switch input, keyless entry keypad, door lock control switches, Passive Anti-Theft System (PATS) input, and the Remote Keyless Entry (RKE) transmitters. If the perimeter alarm is armed, and the BCM (Body Control Module) receives an input indicating an unauthorized entry into the vehicle or the ignition is turned to the RUN position without a programmed PATS (Passive Anti-Theft System) key, the BCM (Body Control Module) activates the perimeter alarm. When the perimeter alarm is activated, the horn sounds and both the turn signals and courtesy lights flash in regular intervals.

If the driver door is unlocked by using a key in the door lock cylinder and then opened, the perimeter alarm starts a 12-second countdown. During the 12-second countdown there is a chime from the Instrument Panel Cluster (IPC) and the message center displays TO STOP ALARM START VEHICLE. If the alarm is not deactivated during this countdown, the perimeter alarm activates.

Battery Disconnect

If the battery is disconnected and then reconnected, the perimeter alarm remains in the same state (disarmed, pre-armed, armed, or activated) it was prior to the battery disconnect.

Alarm Event PIDs

The BCM (Body Control Module) has PIDs available that show what caused the last alarm events. The 4 BCM (Body Control Module) alarm event PIDs are ALARM_EVT_1 through 4. The cause for the most recent alarm activation is always listed in the first alarm event PID. These PIDs display what caused the alarm to activate and can be a very useful tool when trying to identify the cause of a false alarm activation.