Body Control Systems: Description and Operation

Module Controlled Functions

Body Control Module (BCM)

The Body Control Module (BCM) is located behind the driver side cowl panel and controls the following:

- Interior lighting

- Exterior lighting

- Dimmable backlighting

- Battery saver function

- Delayed accessory relay function

- Horn

- Brake shift interlock

- Power door locks (vehicles without Intelligent Access (IA))

- Remote Keyless Entry (RKE) system

- Perimeter alarm

- Passive Anti-Theft System (PATS) (vehicles without IA (Intelligent Access))

- Remote engine start

- Tire Pressure Monitoring System (TPMS)

Refer to the appropriate system for system specific information and diagnostics.

Battery Saver

NOTE: Time-out is 1 minute if the vehicle has less than 80 km (50 miles).

To save battery voltage, the BCM (Body Control Module) provides automatic shut-off of some system controlled components after a time-out period. REFER to Lighting and Horns (Exterior Lighting) or Lighting and Horns (Interior Lighting) for system specific information.

Post Crash Alert Feature

The post crash alert is a function controlled by the BCM (Body Control Module). If the Restraints Control Module (RCM) determines an impact of enough severity (the air bags may or may not be deployed), the post crash alert function activates. The post crash alert function activates the hazard lamp function and cycles the horn on 3 times, then off for 4 seconds, and repeats this cycle until the battery is discharged or the function is turned off. The post crash alert function can be turned off by:

- pressing the hazard flasher lamp switch (which may need to be pressed twice).

- pressing the RKE (Remote Keyless Entry) transmitter UNLOCK button.

- pressing the RKE (Remote Keyless Entry) transmitter PANIC button.

Remote Function Actuator (RFA) Module

The Remote Function Actuator (RFA) module (located behind the glove compartment) is equipped on vehicles with Intelligent Access (IA) and controls the following:

- Power door locks (vehicles with IA (Intelligent Access))

- Remote Keyless Entry (RKE) system

- Key validation (part of the Passive Anti-Theft System (PATS)

Refer to the appropriate system for system specific information and diagnostics.