Principles of Operation

Anti-Theft

Principles of Operation

Perimeter Anti-Theft

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

The perimeter anti-theft system (integral to the SJB) provides for vehicle security through an audible and visual notification if the vehicle doors, luggage compartment lid, or hood are opened while the system is armed. The system arms when:

- the doors, the luggage compartment lid, and the hood are closed.
- the key is in the OFF position.
- the vehicle is electronically locked using the lock button on the Remote Keyless Entry (RKE) transmitter (part of the Integrated Keyhead Transmitter (IKT) key), the keyless entry keypad (if equipped), or a door lock control switch (with a front door open, then closed).

There is a 20-second pre-arm delay after which each door, luggage compartment lid, and hood is armed. If a door, luggage compartment lid, or hood is open, the system still arms all the other closures. Only the open door, luggage compartment lid, or hood remains disarmed until it is closed. When the open entry point is closed, that entry point enters a 20-second pre-arm delay, then arms.

The hood switch and door ajar switches register as normally closed. The luggage compartment lid ajar switch registers as a normally closed switch. The SJB monitors the status of the hood switch, the luggage compartment lid ajar switch and door ajar switches. If these switches indicate an open entry point, the SJB energizes the horn and flasher relays, causing the horn to sound and the turn signal lamps to flash. The SJB disarms the perimeter alarm when it receives:

- an UNLOCK command through the keyless entry keypad (if equipped).
- an UNLOCK command through the RKE transmitter (part of the IKT key).
- a valid Passive Anti-Theft System (PATS) ignition key is turned to the ON position.

Alarm Event PIDs

The SJB has PIDs available that show what caused the last alarm events. The SJB has 4 alarm event PIDs and are AL_EVT1 through 4. The most recent alarm event is always listed in the first alarm event or trigger PID. These PIDs display what caused the alarm to trigger and can be a very useful tool when trying to identify the cause of a false alarm trigger.