Body Control Systems: Description and Operation
Module Controlled Functions
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
There are 2 multifunction electronic modules on this vehicle. They include the:
- Driver Seat Module (DSM)
- SJB
Driver Seat Module (DSM)
The DSM (if equipped) controls the exterior memory mirrors and the driver memory seat functions and is located under the driver seat.
Smart Junction Box (SJB)
NOTE: The time out for the battery saver relay and the accessory delay relay 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 Lighting and Horns. For the accessory delay relay, refer to Windows and Glass.
The SJB is a combination of a multifunction electronic module and an interior fuse panel and is located under the instrument panel on the left hand side of the vehicle. The SJB functions control multiple vehicle systems, which include:
- Accessory delay
- Battery saver relay
- Brake shift interlock
- Exterior lighting
- Global open (front windows only)
- Heated rear window
- Horn
- Interior lighting
- Perimeter anti-theft (MKX only)
- Power locks
- Remote Keyless Entry (RKE) system
- Tire Pressure Monitoring System (TPMS)
- Windshield wiper
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 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) that an air bag deployable impact has occurred.
The IC sends the message to the SJB over the Medium Speed Controller Area Network (MS-CAN). The SJB activates the post crash alert function by repeatedly cycling the horn on 3 times, then off for 4 seconds, until the battery dies or the function is turned off. The hazard lights also flash with the horn sounding, but keep flashing during the horn off cycle.
The post crash alert function can be turned off by:
- pressing the hazard switch (which may need to be pressed more than once).
- pressing the RKE transmitter UNLOCK button.
- pressing the RKE transmitter PANIC button.
The post crash alert feature acts similar to the 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 does not deactivate the post crash alert, but deactivates an activated perimeter alarm.
The post crash alert function cannot be configured off.
Welcome/Farewell Strategy
The welcome/farewell strategy controlled by the SJB has been modified to a new strategy. When the vehicle has been unlocked using the UNLOCK button on the RKE transmitter, the new strategy listed is activated. Also, when the vehicle is locked using the RKE, the new strategy is activated. This new strategy is not used by the SJB if the vehicle is opened using a key in the door lock cylinder or if the vehicle is exited without a button press of the RKE transmitter. Locking (or unlocking) the doors with the door lock switch also does not affect this strategy. Refer to the following tables for the strategy comparison.
Old Strategy
- Turn signals provide a 250 ms flash when the lock button is pressed. When the unlock button is pressed, there is no flash.
- Illuminated entry has headlamps, park lamps, puddle lamps, interior lights and backlighting on.
- Illuminated exit has puddle lamps, interior lights on with the headlamps, park lamps and backlighting off.
Old Strategy
New Strategy
- Turn signals provide a 400 ms flash when the lock button is pressed. When the unlock button is pressed, there is a single 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
