Anti-Theft - Perimeter
Anti-Theft
Principles of Operation
Without Intelligent Access (IA)
The Body Control Module (BCM) controls the operation of the perimeter alarm based on the following inputs:
- the door ajar switch inputs
- liftgate ajar input
- hood switch input
- keyless entry keypad
- door lock control switches
- Passive Anti-Theft System (PATS) input,
- Remote Keyless Entry (RKE) transmitters
The BCM (Body Control Module) receives direct input from all the ajar switches, the hood switch, keyless entry keypad, the door lock control switches, and the PATS (Passive Anti-Theft System) transceiver. It receives messages from the Tire Pressure Monitor (TPM) module over the Medium Speed Controller Area Network (MS-CAN) for the RKE (Remote Keyless Entry) feature.
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 transitioned to the RUN mode 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 and opened using a key in the door lock cylinder, the perimeter alarm starts a 12 second countdown. During the countdown a chime sounds and the message center displays TO STOP ALARM START VEHICLE. If the alarm is not deactivated during this countdown, the perimeter alarm activates.
With Intelligent Access (IA)
The Body Control Module (BCM) controls the operation of the perimeter alarm based on the following inputs:
- the door ajar switch inputs
- liftgate ajar input
- hood switch input
- keyless entry keypad
- door lock control switches
- Passive Anti-Theft System (PATS) input,
- Remote Keyless Entry (RKE) transmitters
- Intelligent Access (IA) input
The BCM (Body Control Module) receives direct input from all the ajar switches, the hood switch, and the door lock control switches. The Remote Function Actuator (RFA) module receives direct input from the keyless entry keypad, it also receives input from the TPMS (Tire Pressure Monitoring System) module for the RKE (Remote Keyless Entry) and IA (Intelligent Access) features. The BCM (Body Control Module) receives the door lock/unlock status from the RFA (Remote Function Actuator) module over the Medium Speed Controller Area Network (MS-CAN) to determine the correct perimeter alarm state.
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 transitioned to the RUN mode 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 and opened using a key in the door lock cylinder, the perimeter alarm starts a 12 second countdown. During the countdown a chime sounds 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.