Body Control Systems: Description and Operation

Module Controlled Functions

Smart Junction Box (SJB)

The Smart Junction Box (SJB) (located under the instrument panel to the left of the steering column) has control of the following systems:

- Interior lighting

- Exterior lighting

- Dimmable backlighting

- Battery saver function

- Delayed accessory relay function

- Horn

- Heated rear window

- Brake shift interlock

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

- Remote Keyless Entry (RKE) system (vehicles without IA (Intelligent Access))

- Perimeter alarm

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

- 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).

The SJB (Smart Junction Box) provides automatic shut-off of some system controlled components after a time-out period in order to save battery voltage. A timer in the SJB (Smart Junction Box) is started when the ignition is turned OFF and all the doors are closed. When 10 minutes have elapsed, the voltage is automatically shut off by the SJB (Smart Junction Box). While the SJB (Smart Junction Box) has voltage disabled, if the ignition changed out of OFF, any door becomes ajar, the UNLOCK button of the RKE (Remote Keyless Entry) transmitter is pressed, a valid keypad code is entered, or the instrument panel dimmer switch is pressed, the SJB (Smart Junction Box) restores voltage and starts the timer again.

Post Crash Alert Feature

The post crash alert is a function controlled by the SJB (Smart Junction Box). 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 is activated. 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 comes on vehicles equipped with Intelligent Access (IA) (located behind the glove compartment) and has control of the following systems/components:

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

- Remote Keyless Entry (RKE) system (in conjunction with the Remote Functions Receiver (RFR))

- Keyless entry keypad

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

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