Antitheft and Alarm Systems: Description and Operation

The anti-theft system consists of the following components:
^ anti-theft indicator
^ anti-theft relay
^ left door key lock switch
^ hood anti-theft switch
^ liftgate key lock switch
^ right door key lock switch
^ Smart Entry Control (SEC)/timer module
^ inhibit relay

PRINCIPLES OF OPERATION

System Arming
With the ignition in the off position and the key removed, there are three ways to arm the anti-theft system. When exiting the vehicle, locking the door using the door lock switch will ground the lock input circuit to the SEC/timer module. This will cause the doors to lock, and will arm the anti-theft system in 30 seconds, providing that all doors are closed within 30 seconds of the door lock switch being depressed.

With all of the doors, the hood, and the liftgate closed, locking the door using the key will move the key lock switch into the lock position, grounding the lock input circuit to the SEC/timer module. This will cause the doors to lock, and will arm the anti-theft system in 30 seconds.

With all of the doors, the hood, and the liftgate closed, locking the door by depressing the lock switch on the remote transmitter commands the SEC/timer module to both lock the doors, and arm the anti-theft system. The anti-theft system will arm after 30 seconds.

Triggering the Anti-Theft System
Operation of the Anti-Theft system is controlled by the SEC/timer module. The SEC/timer module monitors the state (open or closed) of the driver door, passenger door, sliding side doors, liftgate, and hood, by means of switches located in each. When either the driver door, passenger door, sliding side doors, liftgate, or hood, is opened a switch closes grounding an input to the SEC/timer module. If the anti-theft system is armed and the door has not been unlocked using either the key or the remote transmitter, the anti-theft alarm will be triggered. When the system has been triggered it will disable the starter motor, flash the exterior lamps, and sound the horn. After 2 1/2 minutes, the exterior lamps and horn will cease, but the starter motor circuit will remain disabled.

Disarming an Untriggered System
When the doors are unlocked using a key, the key lock switch grounds the unlock input to the SEC/timer module, the SEC/timer module then disarms the anti-theft system. The system can also be disarmed by depressing the unlock switch on the remote transmitter, which commands the SEC/timer module to unlock the doors and disarm the anti-theft system.

Deactivating a Triggered System
Disarming a triggered anti-theft system is accomplished in the same manner as with an untriggered system. A triggered anti-theft system can also be disarmed by entering the vehicle and using the key to turn the ignition to the RUN position.

Anti-Theft Indicator
The anti-theft indicator can be in any one of four states, all of which are controlled by the SEC/timer module. The anti-theft indicator will be off when the anti-theft system is not activated or has been disarmed. The indicator will flash 0.5 seconds on, and 0.5 seconds off, if at least one of the front doors, side doors, or liftgate is open. The indicator will remain on steady for 30 seconds during the arming sequence. Finally, the anti-theft indicator will flash 0.2 seconds on and 2.4 seconds off, to indicate that the anti-theft system is fully armed.