Antitheft and Alarm Systems: Description and Operation

INTRODUCTION
Vehicles equipped with the Vehicle Theft Security System (VTSS) system, the doors, liftgate, hood and ignition circuit are monitored by the Body Control Module (BCM) when the system is armed. The VTSS will prevent the engine from starting until the BCM receives a disarm signal. If the VTSS is triggered, the horn will pulse, headlamps/marker lamps will flash, and the VTSS warning lamp will flash. If BCM determines the threat to be false and the VTSS is not triggered again, the system will shut down and rearm itself after three minutes. The VTSS monitoring portion of the system is split into two sections. The engine compartment section and the passenger compartment section. If a malfunction occurs in the engine compartment section, the passenger compartment section would still arm and function normally If an electrical malfunction occurs in either section of the system a Diagnostic Trouble Code (DTC) would be stored the BCM memory to aid system repair. DTC's can be retrieved using scan tool (DRB) attached to the diagnostic connector above the accelerator pedal.

Enabling
To initialize the VTSS feature the operator must, with the engine compartment hood open, cycle the key in the liftgate key cylinder to the unlock position giving the BCM a disarm signal. At this time the visual alarm outputs the headlamps and marker lamps will function. However the audio alarm output the horn and engine disable portion of the VTSS will not function until there has been twenty consecutive engine run cycles. When this has occurred the total VTSS will function.

If during alarm being set the BCM receives a request from the RKE module to enter PANIC mode the BCM will cancel the alarm, return VTSS armed state and then perform the RKE PANIC feature.

SYSTEM OPERATION
Arming Procedure
Method - A
1. With the key removed from the ignition lock and any door open, actuate one of the following:
- Power door lock button to LOCK,
- Key fob LOCK button
- Door lock key cylinder to locked position.
2. Close all opened doors.
3. After the last door is closed, an arming time-out period of sixteen seconds will start, then the VTSS will become armed.

Method - B
Actuating the key fob transmitter LOCK button, key locking the front doors or liftgate with the doors closed and the ignition locked will begin the arming time-out period. If method-A, 16 second time-out sequence was in process when method-B was actuated, the 16 second time-out will restart from the time of the second actuation.

If the security lamp does not illuminate at all upon final door closure, it indicates that the system is not arming.

The current VTSS status armed or disarmed shall be maintained in memory to prevent battery disconnects from disarming the system.

Time-Out Period
The VTSS requires 16 consecutive seconds to time-out and arm the alarm. If a door is key unlocked, key fob unlocked. or the ignition is switched ON, the VTSS will cancel out. To reset the VTSS, perform methods A or B.

Triggering The VTSS
After the VTSS is armed, following actions will trigger the alarm:
- Opening any door.
- Opening the hood
- Turning the ignition to the ON or unlock position.
- The ignition switch can be turned to the accessory position without triggering alarm system.