Antitheft and Alarm Systems: Description and Operation
DESCRIPTIONWhen triggered, the Anti-theft Protection System honks the horn and flashes the Head-lamps and Parking Lamps at an intermittent rate of approximately 80 cycles per minute. In addition, the Starting System is disabled until the system is disarmed.
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 Module 296 (W/P) 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 pulsating ground signal through the 343 (DB/LG) wire to flash the 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. The Indicator lamp will now 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 Key-less Entry "UNLOCK" code. Either of these actions applies voltage to the Module through the 118 (PK/O) or the 163 (R/O) wires to cancel arming. The Alarm Indicator will start flashing again. Turning the Ignition Switch to "RUN" or "ACC" will also cancel arming by applying voltage to the Module on the 296 (W/P) 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 627 (BK/O) wire to trigger the alarm circuits in the Module. The Module then provides a pulsating ground signal to the Alarm Indicator through the 343 (DB/LG) wire and to the Horn Relay coil through the 6 (Y/LG) wire. Pulsating battery voltage is applied to the Lo Beam Headlamps and the Parking Lamps through the 218 (W/P) wire.
At the same time, the Module prevents current from energizing the Starter Relay by means of an open circuit between wires 23 (T/LG) and 32 (RILB) and the car cannot be started.
An Anti-theft Trunk Lid Switch is also included in the system. If an attempt is made to remove the trunk lock (punch out, etc.), the switch closes and a ground signal is applied to the Module through the 26 (W/P) 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.
An Anti-theft Hood Switch is also part of the system. If the hood is forced open while the system is armed, the switch closes and a ground signal is applied to the module through the 26 (W/P) wire. This triggers the system in the same manner as the Anti-theft Trunk Lid Switch.
The Ignition Switch has a built in Anti-theft Switch. If an attempt is made to remove the Ignition Cylinder, the switch closes and a ground is applied to the module through the 936 (DG/W) wire. This triggers the system in the same manner as previously decided for opening a door.
Disarming the System
To disarm the system, a front door can be unlocked with the key, with the remote keyless entry transmitter, or with the Keyless Entry Keypad.
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 on the Keyless Entry Keypad or pressing the Unlock button on the keyless entry transmitter 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 "ACC" or "RUN".
The battery voltage applied to the Module on the 296 (W/P) wire disarms the system.