Body Control Systems: Description and Operation

Module Controlled Functions

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

The SJB is the only multifunction electronic module on this vehicle.

Smart Junction Box (SJB)

NOTE: The time out for the battery saver relay and the accessory delay relay (both are controlled by the SJB) is one 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 Courtesy Lamp. For the accessory delay relay, refer to Windows. Courtesy Lamp

The SJB controls and provides diagnostic information for the following:

- Autolamps
- Battery saver function
- Delayed accessory function
- Exterior lighting
- Horn
- Interior lighting
- Power door locks
- Remote Keyless Entry (RKE) system/keyless entry keypad
- Tire Pressure Monitoring System (TPMS)

The SJB controls multiple vehicle systems including:

- Locking and unlocking all of the doors
- Panic alarm function (horn sounding and parking lamps flashing intermittently in regular intervals)
- Single horn chirp confirmation when the lock button is pressed on the RKE transmitter twice within 3 seconds and all of the doors are closed, double horn chirp confirmation if one or more doors are open
- Single flash of the parking lamps when the lock button is pressed on the RKE transmitter with all of the doors closed. There is no parking lamp flash if the RKE transmitter LOCK button is pressed and one or more doors are ajar
- Turning on the interior lamps when the doors are unlocked using an RKE transmitter
- TPMS

The SJB also monitors the door ajar signals to determine if a single or double horn chirp confirmation is necessary when locking the doors using the RKE transmitter. Also, if all of the doors are closed and the doors are locked using the RKE transmitter, the SJB turns off the interior lamps. If one or more doors are detected open by the door ajar switches, the SJB will not turn off the interior lamps.

Post Crash Alert

With the post crash alert function, if the Restraints Control Module (RCM) determines an impact of severity enough to deploy air bags has occurred (the air bags may or may not be deployed by the RCM), the RCM will send a message to the IPC over the High Speed Controller Area Network (HS-CAN), which will send the message to the SJB over the Medium Speed Controller Area Network (MS-CAN) and the SJB will activate the post crash alert function by cycling the horn on 3 times, then off for 4 seconds, then on 3 times, etc., in this cycle until the battery dies or the function is turned off. The hazard lights will also flash with the horn sounding, but will 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 RKE transmitter UNLOCK button.
- pressing the RKE transmitter PANIC button (may need to be pressed more than once).

This feature acts similar to a perimeter alarm, but the horn cycle is different. The perimeter alarm function cycles the horn on and off, in regular intervals until 2 minutes and 45 seconds have elapsed, the battery dies or the function is turned off. Turning the ignition to the ON position will not deactivate this function. This vehicle does not have a perimeter alarm.

The post crash alert function cannot be configured off.