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 vehicle is equipped with an SJB and a Driver Seat Module (DSM).

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 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 will be 10 minutes, as described in the Owner's Literature. For the battery saver relay, refer to Courtesy Lamp. For the accessory delay relay, refer to Windows. Testing and Inspection

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

- Accessory delay relay
- Battery saver relay
- Exterior lighting
- Interior lighting
- Heated rear window
- Horn
- Perimeter anti-theft
- Post crash alert
- Power door locks (including smart locks, autolocking and liftgate/luggage compartment lid release)
- Remote Keyless Entry (RKE)/keyless entry keypad
- Tire Pressure Monitoring System (TPMS)

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 Panel Cluster (IPC) 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) and 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) UNLOCK button.
- pressing the IKT PANIC button.

This feature acts similar to the perimeter alarm, but the horn cycle is different. The perimeter alarm function sounds the horn on and off, in regular intervals until 2 minutes and 45 seconds have elapsed, the battery dies or the function is deactivated. Turning the ignition to the ON position does not deactivate the post crash alert function, but deactivates an activated perimeter alarm. The post crash alert function cannot be configured off.

Driver Seat Module (DSM)

The DSM controls the user selected comfort functions. These functions are the memory seat, memory mirrors and memory pedals settings. Up to 2 personal settings can be programmed into the DSM memory and when selected, (by pressing the UNLOCK button of an IKT key, or pressing one of the memory switches on the driver door, if they have been programmed), the DSM returns the user adjustable features to the programmed positions. For programming the memory feature, refer to Locks.