Vehicle Theft Security System (Vtss)

VEHICLE THEFT SECURITY SYSTEM
The VTSS is designed to provide perimeter protection against unauthorized use or tampering by monitoring the vehicle doors and the ignition system. If unauthorized use or tampering is detected, the system responds by pulsing the horn and flashing the headlamp high beams. If the vehicle is also equipped with the optional Sentry Key Immobilizer System (SKIS), which provides passive vehicle protection by preventing the engine from operating unless a valid electronically encoded key is detected in the ignition lock cylinder.

The VTSS system monitors the door ajar switches and ignition switch to detect unauthorized entry into the vehicle. Once the vehicle is "armed", any one of these inputs can cause the VTSS system to be tripped. Once tripped, the horn and lights will pulse for 3 minutes and if an attempt is made to start the engine with a non-programmed SKIM key, it will start and stall. If the trigger condition is still present, the lights will continue to flash for an additional 15 minutes, after which the system will stop pulsing the lights and return to the "armed" state. The cause of the last 4 alarm triggers is stored by the CTM and may be retrieved by the DRB III. The system may be disarmed by either an unlock command from a valid RKE key fob by using a key in either door, or by using a valid SKIM key in the ignition. The door key cylinders are equipped with disarm switches. There is also a VTSS lamp on the dash that provides information to the driver about the state of the vehicle theft system.

The VTSS includes the following major components, which are described in further detail elsewhere in this service information:
- Central Timer Module
- Door Ajar Switch
- Door Cylinder Lock Switch
- Horn Relay
- Security Indicator

Hard wired circuitry connects many of the VTSS components to each other through the electrical system of the vehicle. Refer to the appropriate wiring information.

A Central Timer Module (CTM) is used on this model to control and integrate many of the electronic functions and features included in the Vehicle Theft Security System (VTSS). In the VTSS, the CTM receives inputs indicating the status of the door ajar switches, the door cylinder lock switch, and the ignition switch. The programming in the CTM allows it to process the information from all of these inputs and send control outputs to energize or de-energize the horn relay, the headlamp high beams, and the security indicator. If the VTSS alarm is triggered, the CTM pulses the horn for 3 minutes and flashes the headlamp high beams and security indicator for 15 - 18 minutes or until the system is disarmed. The control of these inputs and outputs are what constitute all of the features of the VTSS. Following is information on the operation of each of the VTSS features.

Enabling
The CTM must have the VTSS function electronically enabled in order for the VTSS to perform as designed. The logic in the CTM keeps its VTSS function dormant until it is enabled using a DRB III scan tool. The VTSS function of the CTM is enabled on vehicles equipped with the VTSS option at the factory, but a service replacement CTM must be VTSS-enabled by the dealer using a DRB III scan tool. Refer to the appropriate diagnostic information.

Arming
Passive arming of the VTSS occurs when the vehicle is exited with the key removed from the ignition switch, the headlamps are turned OFF, and the doors are locked while they are open using the power lock switch, or locked after they are closed by turning either front door lock cylinder to the lock position using the key. The power lock switch will not function if the key is in the ignition switch or the head- lamps are turned on with the driver side front door open. The VTSS will not arm if the doors are locked using the mechanical lock button. Active arming of the VTSS occurs when the "Lock" button on the Remote Keyless Entry (RKE) transmitter is depressed to lock the vehicle. For active arming to occur, the doors must be closed and the ignition switch must be in the OFF position when the RKE transmitter "Lock" button is depressed.

Pre-arming of the VTSS is initiated when a door is open when the vehicle is locked using a power door lock switch or a key in the door lock cylinder (passive), or when the RKE transmitter "Lock" button is depressed (active). Pre-arming will not occur if the key is in the ignition switch or the headlamps are turned ON with the driver side front door open. When the VTSS is pre-armed, the arming sequence is delayed until all of the doors have been closed.

Once the VTSS begins the passive or active arming sequence, the security indicator in the instrument cluster will flash rapidly for about seventeen seconds. This indicates that the VTSS arming is in progress. If the ignition switch is turned to the ON position, a door is opened, a door is unlocked by any means, or the RKE "Panic" button is depressed during the seventeen second arming process, the security indicator will stop flashing and the arming process will abort. Once the seventeen second arming sequence is successfully completed, the security indicator will flash at a slower rate, indicating that the VTSS is armed.

Disarming
Passive disarming of the VTSS occurs when the vehicle is unlocked using the key to unlock either front door or, if the vehicle is equipped with the optional Sentry Key Immobilizer System (SKIS), by turning the ignition switch to the ON position using a valid SKIS key. Active disarming of the VTSS occurs when the vehicle is unlocked by depressing the "Unlock" button of the RKE transmitter. Once the alarm has been activated, either disarming method will also deactivate the alarm. Depressing the "Panic" button on the RKE transmitter will not disarm the VTSS.

Power-up Mode
When the armed VTSS senses that the battery has been disconnected and reconnected, it enters its power-up mode. In the power-up mode the alarm system remains armed following a battery failure or disconnect. If the VTSS was armed prior to a battery disconnect or failure, the technician or vehicle operator will have to actively or passively disarm the alarm system after the battery is reconnected. The power-up mode will also apply if the battery goes dead while the system is armed, and battery jump-starting is attempted. The VTSS will be armed until the technician or vehicle operator has actively or passively disarmed the alarm system. If the VTSS is in the disarmed mode prior to a battery disconnect or failure, it will remain disarmed after the battery is reconnected or replaced, or if jump-starting is attempted.

Tamper Alert
The VTSS tamper alert feature will sound the horn three times upon disarming, if the alarm was triggered and has since timed-out (about eighteen minutes). This feature alerts the vehicle operator that the VTSS alarm was activated while the vehicle was unattended.