Antitheft and Alarm Systems: Service and Repair

Enabling
The CTM must have the VTSS 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. Refer to the appropriate diagnostic information.

The VTSS engine no-run feature is disabled when it is shipped from the factory. This is done by programming within the Powertrain Control Module (PCM). The logic in the PCM prevents the VTSS engine no-run feature from arming until the engine start counter within the PCM sees twenty engine starts. The VTSS no-run feature must be enabled by the dealer when the vehicle is received from the assembly plant. Once the VTSS engine no-run feature has been enabled, it cannot be disabled unless the PCM is replaced. The same VTSS engine no-run feature enable logic will apply anytime the PCM is replaced.

Arming
To arm the system, the ignition must be OFF and all doors must be closed and locked using either front door key cylinder lock switch, power door lock switch or the RKE transmitter. Using a key in either rear door or pressing the mechanical lock will not initiate arming the VTSS. The delay lock feature will delay the arming process until all doors are closed.

Once the VTSS begins to arm, the CTM will activate the security lamp output at a 1 Hz rate. During this process the arming process will terminate if the ignition is turned on, if a door is opened, if the doors are unlocked using the door lock switch or the RKE transmitter, or if the front doors are unlocked using the key. After fifteen seconds of the arming process, the security lamp will go OFF and the VTSS Will be armed. Once the vehicle is armed the ignition may be turned to the accessory position (to listen to radio, etc.) without triggering the alarm. The VTSS can only be disarmed using the key or the RKE transmitter.

Passive arming of the VTSS occurs when the vehicle is exited with the key removed from the ignition switch, the headlamps are turned OFF, 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 buttons. Active arming of the VTSS occurs when the "Lock" button on the Remote Keyless Entry (RKE) transmitter is depressed. 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. However, once the VTSS arming process has been completed, the ignition switch can be turned to the Accessory position without triggering the alarm.

Pre-arming of the VTSS is initiated when a side or rear door is open when the vehicle is locked using a power 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 side and rear doors have been closed.

Once the VTSS begins passive or active arming, the security indicator in the ElectroMechanical Instrument Cluster (EMIC) will flash rapidly for about fifteen seconds. Turning a key in the ignition switch, opening a door, or unlocking a door by any means during the fifteen second arming process will cause the security indicator to stop flashing and the arming process to abort. Once the fifteen second arming function is successfully completed, the 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. 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.

Triggering The VTSS
Once the VTSS is armed, the alarm will trigger if any of the doors are opened or if the key is turned the Run/Start position. When triggered, the CTM will instruct the PCM to turn OFF the engine after two seconds and will pulse the horn and headlamps at a specified duty cycle and frequency. The audible (horn) warning will continue for three minutes then terminate. The visual (headlamps) warning will continue for fifteen additional minutes then terminate. The engine will continue to start and quit until the VTSS is disarmed.


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. 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 discharges while the system is armed, and battery jump-starting is attempted. The engine no-run feature will prevent the engine from starting until the alarm system has been actively or passively disarmed.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
If the VTSS was triggered during the last armed period, the next time it is disarmed the CTM will activate three horn chirps. To determine what caused the alarm to be tripped, using the DRB select "Theft Alarm" "Monitor Display" and observe: "Alarm Tripped by". This is a great tool to use when a customer complains that the alarm went OFF and cannot determine what triggered it.
The VTSS tamper alert feature will sound the horn three times upon disarming, if the alarm was triggered and has since timed-out (about fifteen minutes). This feature alerts the vehicle operator that the VTSS alarm was activated while the vehicle was unattended.