Principles of Operation

The smart junction box (SJB) monitors the door ajar switches (which are open with the door closed and closed with the door open), the hood switch (closed with the hood closed and open with the hood open), the liftgate glass ajar switch (closed with the liftgate glass closed), and the liftgate switch (closed with the liftgate closed). When the SJB receives a signal from one or more of the monitored switch(es) indicating unauthorized entry into the vehicle, the SJB intermittently grounds the horn relay and also intermittently sends voltage to the turn signal lamps. The horn relay closes, supplying voltage to the horn. The SJB cycles the ground to the horn relay and voltage to the turn signal lamps, on and off, while the system is activated. The SJB monitors the key-in-ignition switch and does not allow the perimeter anti-theft feature to arm until after the key is removed from the ignition switch, all doors, hood, liftgate and liftgate glass are closed, and 20 seconds have elapsed after locking the vehicle. After all of these criteria have been met, the anti-theft feature will arm.