Antitheft and Alarm Systems: Description and Operation
DESCRIPTIONWhen triggered, the Anti-theft Protection System honks the horn and flashes the Lo Beam Headlamps and Park Lamps at a rate of approximately 80 cycles per minute. In addition, the Starting System is disabled until the System is disarmed.
OPERATION
Arming the System
The System is ready to arm any time the Ignition Switch is turned "OFF" and a door is opened. Voltage to the Anti-theft Controller Module, 294 (W/LB) wire, is removed when the Ignition Switch is turned "OFF". Opening a door closes the Door Ajar Switch in the open door, and a ground path is provided on the 627 (BK/O) wire to the Module. This action causes the Module to apply a pulsing ground signal through the 343 (DB/LG) wire to flash the Anti-theft Alarm Indicator Lamp. With the Ignition Switch "OFF" and a door open, locking the doors with the Power Door Lock Switch or depressing the last two Keyless Entry Buttons begins the arming sequence. Either of these actions applies voltage to the Module on the 117 (PK/BK) wire, causing the Indicator Lamp to glow steadily.
System arming can be cancelled before all doors are closed by unlocking the door with the Power Door Lock Switch or by using the Keyless Entry "UNLOCK" code. Either action applies voltage to the Module through the 118 (PK/O) wire to cancel arming. The Alarm Indicator will start flashing again. Turning the Ignition Switch to "RUN" will also cancel arming by applying voltage to the Module on the 640 (R/Y) wire.
The arming cycle is completed by closing all doors. Approximately thirty seconds after the last door is closed, the Indicator Lamp turns off, indicating the arming cycle is complete.
Triggering the System
Opening any door without disarming the System triggers the alarm (lamps and horn) for three minutes, even if the door closes. After three minutes, the lamps and horn will turn off and the Module will return to an armed state. Also, the Starting System is disabled and will remain disabled until the System is disarmed.
Once the System is armed, opening any door causes a ground signal through the (BK/O) wire to trigger the alarm circuits in the Module. The Module then provides a pulsing ground signal to the Alarm Indicator through the 343 (DB/LG) wire and to the Horn Relay coil through the 1 (DB) wire. Pulsating battery voltage is applied to the Lo Beam Headlamps and to the Park Lamps through 218 (W/P) wire.
At the same time, the Module disables the Starting System by grounding the Start Interrupt Relay through circuit 342 (LG/P). This, in turn, prevents current flow through the Start Interrupt Relay.
Trunk Lid Anti-theft and Anti-theft Hood Switches are also included in the System. If the hood is forced open or the trunk lock cylinder is removed (punched out, etc.). the switch closes, and a ground signal is applied to the Module through the 23 (T/LG) wire. This triggers the System in the same manner as previously described for opening a door. The trunk key can be used to open the trunk without triggering the System.
Disarming the System
To disarm the System, a front door can be unlocked with the key or the Keyless Entry "UNLOCK" code can be used.
Unlocking a front door with the key provides a ground path through a Door Disarm Switch and the 25 (DG/P) wire to the Module. This ground signal disarms the System.
Entering the "UNLOCK" code applies battery voltage through the 163 (R/O) wire to the Module to disarm the System.
If the driver arms the System and remains in the car (all doors closed), the untriggered System can be disarmed by inserting the key in the Ignition Switch and turning the Switch to "RUN". The switched voltage applied to the Module on the 294 (W/LB) wire disarms the System.