Antitheft and Alarm Systems: Description and Operation

VEHICLE THEFT SECURITY SYSTEM
This passive system is designed to protect against theft. The vehicle theft security system (VTSS) is part of the Body Control Module, which monitors vehicle hood, doors, liftgate, and ignition for unauthorized operation. The alarm activates by sounding the horn, flashing the headlamps, park and tail lamps, and the VTSS indicator lamp. The VTSS will also prevent the engine from starting until the BCM receives a disarm signal.

Passive arming occurs upon normal vehicle exit by turning the ignition OFF, opening the driver's door, locking the doors with the power lock, and closing the driver's door or locking the doors with RKE. Manual arming occurs by using the key to lock the doors after closing them. The indicator lamp in the information center will flash for 15 seconds, showing that arming is in progress. If no monitored systems are activated during this period, the system will arm.

NOTE: If hood is not secure during arming sequence, the lamp will stay lit and not flash. The system will arm with hood not secured (hood ajar switch closed). System will not arm if passenger compartment is not secure (all switches open).

When something triggers the alarm, the system will signal the headlamps, park lamps, and horn for about 3 minutes.

Tamper Alert - If the horn sounds three times when either front door or the liftgate is unlocked, it means the alarm was activated. Check the vehicle for tampering.

Manual Override - The system will not arm if the doors are locked using the manual lock control (by hand) or if the locks are actuated by an inside occupant after the door is closed.

When an unauthorized entry into the vehicle occurs, the VTSS sends a message via the CCD bus to the powertrain control module that it is not OK to start the engine. The powertrain control module then zeroes out the pulse width to the fuel injectors after the engine has been started, thus shutting down the engine (start and stall condition). The engine will not start until the system is disarmed.

To verify the system, proceed as follows:
1. Open the driver's door.
2. Remove the ignition key (but keep it in hand).
3. Lock the doors with the power lock switch.
4. Close the driver's door. NOTE: After the doors are closed, locking the doors with RKE will also arm the system.

NOTE: IF THE VTSS INDICATOR LAMP FLASHED, THE SYSTEM IS OPERATIONAL AND VERIFIED. IF NOT, THERE MAY BE A PROBLEM WITH THE SYSTEM.

System initialization is accomplished by:
1. Opening the hood to ensure the hood ajar circuit is closed.
1. Rotating the key in liftgate cylinder to unlock/disarm position.

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 four consecutive engine run cycles. When this has occurred, the total VTSS will function.

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

Arming/Disarming
Active arming occurs when the remote keyless entry transmitter is used to lock the vehicle doors, whether the doors are open or closed. If one or more doors are open, the arming sequence is completed only after all door are closed.

Passive disarming occurs upon normal vehicle entry (unlocking either front door or the liftgate with the key). This disarming also will halt the alarm once it has been activated.

Active disarming occurs when the remote keyless entry transmitter is used to unlock the vehicle doors. This disarming also will halt the alarm once it has been activated.

System Self-Test

NOTE: System self-test can be entered only with the DRB.

NOTE: A POWERTRAIN CONTROL MODULE FROM A VEHICLE EQUIPPED WITH A VEHICLE THEFT SECURITY SYSTEM CANNOT BE USED IN A VEHICLE THAT IS NOT EQUIPPED WITH A VEHICLE THEFT SECURITY SYSTEM.

If the VTSS indicator lamp comes on after ignition ON and stays on, the CCD bus communication with the Powertrain Control Module possibly has been lost.

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 timeout 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 timeout and arm the alarm. If a door is key unlocked, key fob unlocked. a door or liftgate is opened, or the ignition is switched ON, the VTSS will cancel out. To reset the VTSS, perform Arming Procedure, 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.