Antitheft and Alarm Systems: Description and Operation
GENERAL DESCRIPTIONThis passive system is designed to protect against vehicle theft. The vehicle theft security system (VTSS) module is a logic-controlled device that monitors vehicle doors, hood, liftgate, and ignition action for unauthorized operation. The alarm activates by sounding the horn, flashing the headlamps, park and tail lamps, and providing an engine "no run" feature.
Passive arming occurs upon normal vehicle exit, which is: turn the ignition off, open the door, lock the doors with the power lock, and close the door. The indicator lamp in the panel will flash for 15 seconds, showing that arming is in progress. Note that this 15-second arming period will start afier the illuminated entry (if equipped) has timed out (courtesy lamps off). If no monitored systems are activated during this period, the system will arm. If the hood switch is not seen by the system, the indicator lamp will remain steadily lit during the arming process, although the system will still arm.
FUNCTIONAL OPERATION
Because of the variety of vehicles covered, some of the instructions may include inputs and outputs that may not be present on a vehicle. Refer to the chart above to determine component application.
When something triggers the alarm, the system will signal for about 18 minutes. For the first three minutes the horn will sound, then the park and headlamps will flash for another 15 minutes. On the Viper, the horn will sound for three minutes, then the park lamps will flash for 15 minutes.
Tamper Alert - If the horn sounds three times when either front door 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 key or the manual lock control.
SYSTEM OPERATION
When an unauthorized entry into the vehicle occurs, the VTSS sends a message via the CCD bus to the Powertrain Control Module (PCM) that it is not OK to start the engine. The PCM 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.
The VTSS module on some vehicles has the capability of providing bias on the CCD bus.
System Initialization - To avoid both an audible alarm and the engine kill feature causing a problem in the assembly plant, an initialization procedure is included in the VTSS system. This procedure requires that the vehicle has recorded 20 engine starts. Therefore, the VTSS system will not be functional on all vehicles and will require dealer verification.
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. (On the Viper, use the remote keyless entry.)
4. Close the driver's door.
NOTE: If the VTSS indicator lamp flashed, the system is operational and verified. If not, 20 engine starts have not occurred, or there is a problem with the system.
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 doors and liftgate are closed.
Passive disarming occurs upon normal vehicle entry (unlocking either front door or 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.
Power Up Alarm Mode - (This information does not apply to LH body vehicles.) When the battery is disconnected, then reconnected, the vehicle theft security system enters its power up alarm mode which:
- flashes the headlamps (except Viper)
- flashes the park and tail lamps
- prevents the engine from running
To exit this mode, the system must be disarmed.