Normal Operation

The Body Control Module (BCM) controls the perimeter alarm system and based on inputs either arms, disarms or activates the alarm. When the alarm is activated, the BCM  sounds the horn and flashes both the turn signals and courtesy lamps in regular intervals. The BCM  receives inputs for the door lock status, hood switch, door ajar and the keyless entry keypad. The BCM  also receives signals from the Remote Keyless Entry (RKE) transmitters. On vehicles equipped with Intelligent Access (IA), the BCM  receives messages from the Remote Function Actuator (RFA) module over the Medium Speed Controller Area Network (MS-CAN) when the vehicle has been locked or unlocked using the IA  or RKE  feature.

For the perimeter alarm to arm and flash the turn signals, the following conditions must be met:

• ignition must be off
• the hood closed
• all doors closed
• the liftgate closed
• an electronic lock command received from an RKE  transmitter, keyless entry keypad, or door lock control switch (front door opened and then shut after lock is pressed).

Once all the conditions are met, the alarm system enters a pre-arm phase and begins a 20-second countdown. After 20 seconds have passed and no unlock command is received or any hood or door is opened, the perimeter alarm arms.

The perimeter alarm is activated when:

• any passenger door, liftgate, or the hood is opened without first receiving an electronic unlock command from a RKE transmitter or keyless entry keypad.
• the driver door is opened without first receiving an unlock command from an RKE  transmitter, keyless entry keypad, or IA  command and the 12-second delay has expired.
• the passenger door or liftgate is opened without first receiving an IA  command (if equipped).
• the ignition is transitioned to RUN without a valid PATS  key read received.

This pinpoint test is intended to diagnose the following: 

• Door ajar input
• Hood switch input
• Liftgate ajar input
• Turn signals
• Keyless entry keypad concern
• RKE  transmitter concern
• BCM