Perimeter Anti-Theft Alarm - Overview

Overview 

The perimeter alarm system deters unauthorized entry into the vehicle by sounding the traffic horn and flashing all the turn signals and interior courtesy lamps. When an unauthorized entry occurs, the horns and lamps activate for 30 seconds. After 30 seconds, the horns stops sounding, but the lamps continue to flash for up to 5 minutes.

The panic alarm operates similar to the perimeter alarm, but only activates using the panic button on the RKE transmitter.

Arming The Perimeter Alarm 

The perimeter alarm is ready to arm any time the ignition is off. The perimeter alarm pre-arms when any of the following occur:

• Pressing the lock button on a RKE transmitter
• Pressing the door lock control switch to the lock position with a front door open, and then closing the door
• Pressing the 7/8 and 9/0 buttons simultaneously on the keyless entry keypad (if equipped)
• Locking the vehicle with the passive entry feature (if equipped)

Once the system is pre-armed, there is a 20-second countdown before the perimeter alarm is armed. Each entry point to the vehicle (hood and doors) is armed separately and must be closed before that entry point begins the 20-second countdown to become armed. If all entry points are closed, the turn signals flash upon locking indicating that all entry points are entering the 20-second countdown.

Perimeter Alarm Activation 

The perimeter alarm has a 12-second delay when the driver front door is opened without using a valid programmed RKE transmitter, the keyless entry keypad (if equipped) or a passive key (if equipped) to unlock the vehicle. During the delay, a chime sounds. If the perimeter alarm is not disarmed within the 12-second delay, the alarm activates.

The perimeter alarm activates when:

• the driver front door is opened without first receiving an unlock command from the passive entry feature (if equipped), the keyless entry keypad (if equipped) or a valid programmed RKE transmitter, and the 12-second delay has expired.
• any other door or the hood is opened without first receiving an electronic unlock command from the passive entry feature (if equipped), the keyless entry keypad (if equipped) or a valid programmed RKE transmitter.
• the ignition transitions to RUN without a valid PATS key read received.
• the BCM detects an attempt by a diagnostic scan tool to establish communication on the CAN.

The perimeter alarm only activates 10 times per arming cycle. After that, the alarm does not activate. To enable the perimeter alarm again, disarm the perimeter alarm and then arm it again.

Disarming The Perimeter Alarm 

The perimeter alarm disarms when:

• pressing the unlock button on a door lock control switch within the 20-second pre-arm.
• the smart unlock feature activates within the initial 20-second pre-arm.
• pressing the unlock button on a valid programmed RKE transmitter.
• using a valid programmed key to change the ignition to RUN.
• entering the correct vehicle unlock code on the keyless entry keypad (if equipped).
• unlocking a front door or opening the tailgate using the passive entry feature (if equipped).

CAN Protection Strategy 

When the perimeter alarm is armed and an attempt is made to establish a scan tool session with the vehicle, the perimeter alarm activates.

Every time an unauthorized access is detected (the alarm activates), all BCM programming, PID monitoring and self-test sessions are blocked for 10 minutes. At the end of the 10 minute time period, the traffic horn chirps to indicate the 1 minute of opportunity to communicate with the vehicle and program keys if none are available.