Body Control Systems: Description and Operation

Module Controlled Functions

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

NOTE: The time out for the battery saver relay and the accessory delay relay (both are controlled by the SJB) is 1 minute if the vehicle has less than 80 km (50 miles). Once the vehicle passes the approximate mileage threshold of 80 km (50 miles), the time out for both relays is 10 minutes, as described by the Owner's Literature. For the battery saver relay, refer to Lighting and Horns. For the accessory delay relay, refer to Windows and Glass.

The SJB is the only multifunction electronic module on this vehicle. The SJB is a combination of a multifunction electronic module and a Central Junction Box (CJB). The following systems are controlled by the SJB:

- Auto locks
- Exterior lamps
- Illuminated entry and interior lamps
- Keyless entry keypad
- Power door locks
- Remote Keyless Entry (RKE) system
- Tire Pressure Monitoring System (TPMS)

The SJB is located under the floor (passenger side front) console.

Post Crash Alert

The post crash alert function is controlled by the SJB. If the Restraints Control Module (RCM) determines an impact of severity enough to deploy the air bags has occurred (the air bags may or may not be deployed by the RCM), the RCM sends a message to the Instrument Cluster (IC) over the High Speed Controller Area Network (HS-CAN), which sends a message to the SJB over the Medium Speed Controller Area Network (MS-CAN). The SJB activates the post crash alert function by sounding the horn 3 times, then off for 4 seconds, then on 3 times, etc., until the battery dies or the function is turned off. The hazard lamps also flash with the horn sounding, however, the hazard lamps keep flashing during the horn off cycle.

The post crash alert function can be turned off by:

- pressing the hazard switch (may need to be pressed more than once).
- pressing the Integrated Keyhead Transmitter (IKT) key UNLOCK button.
- pressing the PANIC button.

This feature acts similar to a perimeter alarm, but the horn cycle is different. Turning the ignition to the ON position does not deactivate this function.

The post crash alert function cannot be configured off.

Welcome/Farewell Strategy

The welcome/farewell strategy is a set of illuminated entry and locking features and is controlled by the SJB. It has been modified to a new strategy from that used in previous model years. Refer to the table below for the new strategy.

New Strategy
- Turn signals provide a 400 ms flash when the lock button is pressed. When the unlock button is pressed there is one long flash.
- Illuminated entry has park lamps, puddle lamps, interior lights and backlighting on (no headlamps).
- Illuminated exit has park lamps, interior lights, backlighting on with the headlamps and puddle lamps off.

New Strategy