Principles of Operation

Anti-Theft

Principles of Operation

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

The SJB monitors the door ajar switches and the hood switch (all doors and the hood must be closed and the key must be out of the ignition lock cylinder). There is a 20-second pre-arm delay after which each door and the hood is armed. From the time each individual input is closed to the time the perimeter alarm is armed for that particular input, is the pre-arm phase. The pre-arm phase is separate for each individual input. If the door lock control switch was pressed to lock with the accompanying door open, all of the inputs that are closed (hood and rest of the doors) would immediately begin their pre-arm phase. After the door (that was open) is closed, then that door would begin its pre-arm phase. This would cause the other inputs to be armed a few seconds before that door. The perimeter alarm arms in stages in relation to which input was closed first after the arming action was received.

In the event of an unauthorized entry, the alarm is activated by the SJB. When the alarm is activated, the SJB intermittently grounds the horn relay, causing the horn to sound in regular intervals, and intermittently powers the turn signals, causing the turn signal lamps to flash in regular intervals.

An unauthorized entry is identified by the SJB whenever a passenger door or hood is detected as having been opened without being disarmed first. If this occurs, the SJB activates the perimeter alarm immediately.

If an unauthorized entry occurs at the driver door with the SJB detecting the driver door ajar switch as being opened (with no electronic unlock command detected by the SJB), there is a 12-second delay with the Instrument Cluster (IC) issuing a chime. If a valid, programmed Passive Anti-Theft System (PATS) key does not turn the ignition switch to the ON position within 12 seconds of the driver door ajar switch being detected as open, the SJB considers this event to be an unauthorized entry and activates the perimeter alarm.

An authorized entry is identified by the SJB as any of the ajar switch inputs detected open after the system has been disarmed.

The door lock control switches cannot disarm the perimeter alarm.