Antitheft and Alarm Systems: Description and Operation
VEHICLE THEFT SECURITY SYSTEM (VTSS)The Vehicle Theft Security System (VTSS) is available factory-installed optional equipment for this model. It is a passive system and is designed to protect against whole vehicle theft. The system monitors vehicle doors and deck lid key cylinder for unauthorized operation.
If the vehicle is equipped with VTSS, it will also include the Sentry Key Immobilizer System (SKIS) factory-installed option.
The VTSS activates:
- Sounding of the horn
- Flashing of the interior lamps
- Flashing of the headlamps
- An engine kill feature (SKIS module controlled)
Refer to the vehicle owner's manual for more information on the use and operation of the Sentry Key Immobilizer System (SKIS).
Passive arming occurs upon normal vehicle exit: Open door, lock with power locks, close door. The Vehicle Theft security LED lamp in the instrument cluster will flash quickly for 15 seconds, indicating that arming is in progress. If no monitored switches are activated during this period, the system will arm. After 15 seconds the LED lamp will continue to flash but at a slower rate. This indicates that the system is armed. If the deck lid key cylinder switch is not sensed by the system, the LED lamp will remain lit during the arming process, although the system will still arm.
The system is to be considered as an active armed system when using:
- The Remote Keyless Entry
- The Central Lock Feature.
If the LED lamp does not illuminate at all upon door closing it indicates that the system is not arming or the LED lamp is not operation. Refer to the System Self-Tests.
Passive disarming occurs upon normal vehicle entry by unlocking either door with the ignition key! remote transmitter. This disarming will also halt the alarm once it has been activated.
A tamper alert exists to notify the driver that the alarm had been activated. If the alarm has since timed-out for at least 3 minutes but not more than 18 minutes the tamper alert will sound. If the trunk lid has been activated the tamper alert will sound till the VTSS is disarmed. The tamper alert consists of 3 horn pulses when the vehicle is disarmed.
The alarm system Will not arm if the doors are locked manually by pushing the lock knobs. This will manually override the system.
The VTSS also deactivates the Universal Transmitter (garage door opener) when the vehicle is armed. The deck lid can only be opened using the key or inside release handle when the VTSS is armed. When the vehicle is disarmed, the systems are restored to normal operation.
SENTRY KEY IMMOBILIZER SYSTEM (SKIS)
The Sentry Key Immobilizer System (SKIS) is designed to provide passive protection against unauthorized vehicle use by preventing the engine from operating without a valid sentry key transponder.
The components of this system are:
- Sentry Key Immobilizer Module (SKIM)
- Sentry Key Transponder
- Vehicle Theft/Security System (VTSS) indicator LED
- Powertrain control Module (PCM)
The SKIM is installed on the steering column near the ignition lock cylinder. The transponder is located under the molded rubber cap on the head of the ignition key. The VTSS indicator LED is located in the instrument cluster.
The SKIS includes three valid Sentry Key transponders from the factory, one being a valet key. This is so the customer can self program new keys if one is lost. If the customer wishes, additional non-coded blank Sentry Keys are available. These blank keys can be cut to match a valid ignition key, but the engine will not start unless the key transponder is also programmed to the vehicle. The SKIS will recognize no more than eight valid Sentry Key transponders at any one time.
The SKIS performs a self-test each time the ignition switch is turned to the ON position, and will store Diagnostic Trouble Codes (DTCs) if a system malfunction is detected. The SKIS can be diagnosed, and any stored DTC can be retrieved using a DRB III scan tool as described in the proper Body Diagnostic Procedures.
CENTRAL LOCK/UNLOCK SYSTEM
The central lock/unlock system uses the Vehicle Theft Security System (VTSS) door key cylinder switches to lock and unlock all doors using the key.
Turning he key to the lock position in the driver's or passenger's door will lock all doors. Turning the key in the driver's door to the unlock position once will unlock driver's door only. Turning the key a second time within five seconds of the first time will unlock all doors. Turning the key in the passenger's door to the unlock position will unlock all doors.
Using the door key cylinder or the RKE transmitter lock/unlock operation will arm/disarm the Vehicle Theft Security System (VTSS).
SENTRY KEY IMMOBILIZER MODULE (SKIM)
The Sentry Key Immobilizer Module (SKIM) contains a Radio Frequency (RF) transceiver and a central processing unit, which includes the Sentry Key Immobilizer System (SKIS) program logic. The SKIS programming enables the SKIM to program and retain in memory the codes of at least two, but no more than eight electronically coded Sentry Key transponders. The SKIS programming also enables the SKIM to communicate over the Chrysler Collision Detection (CCD) data bus network with the Powertrain Control Module (PCM), the instrument cluster and/or the DRB III scan tool.
The SKIM transmits and receives RF signals through a tuned antenna enclosed within a molded plastic ring formation that is integral to the SKIM housing. When the SKIM is properly installed on the steering column, the antenna ring is oriented around the circumference of the ignition lock cylinder housing. This antenna ring must be located within 8 mm (0.31 inches) of the Sentry Key in order to ensure proper RF communication between the SKIM and the Sentry Key transponder.
For added system security, each SKIM is programmed with a unique "Secret Key" code and a security code. The SKIM keeps the "Secret Key" code in memory and sends the code over the CCD data bus to the PCM, which also keeps this code in its memory. The SKIM also sends the "Secret Key" code to each of the programmed Smart Key transponders. The security code is used by the assembly plant to access the SKIS for initialization, or by the dealer technician to access the system for service. The SKIM also stores in its memory the Vehicle Identification Number (VIN), which it learns through a CCD data bus message from the PCM during initialization.
The SKIM and the PCM both use software that includes a rolling code algorithm strategy, which helps to reduce the possibility of unauthorized SKIS disarming. The rolling code algorithm ensures security by preventing an override of the SKIS through the unauthorized substitution of the SKIM or the PCM. However, the use of this strategy also means that replacement of either the SKIM or the PCM units will require a system initialization procedure to restore system operation.
When the ignition switch is turned to the ON or START positions, the SKIM transmits an RF signal to excite the Sentry Key transponder. The SKIM then listens for a return RF signal from the transponder of the Sentry Key that is inserted in the ignition lock cylinder. If the SKIM receives an RF signal with valid "Secret Key" and transponder identification codes, the SKIM then sends a "valid key" message to the PCM over the CCD data bus. If the SKIM receives an invalid RF signal or no response, it sends "invalid key" messages to the PCM. The PCM will enable or disable engine operation based upon the status of the SKIM messages.
The SKIM also sends messages to the instrument cluster over the CCD data bus network to control the VTSS indicator LED. The SKIM sends messages to the instrument cluster to turn the LED on for about three seconds when the ignition switch is turned to the ON position as a bulb test. After completion of the bulb test, the SKIM sends bus messages to keep the LED off for a duration of about one second. Then the SKIM sends messages to turn the LED on or off based upon the results of the SKIS self-tests. If the VTSS indicator LED comes on and stays on after the bulb test, it indicates that the SKIM has detected a system malfunction and/or that the SKIS has become inoperative.
If the SKIM detects an invalid key when the ignition switch is turned to the ON position, it sends messages to the instrument cluster to flash the VTSS indicator LED. The SKIM can also send messages to the instrument cluster to flash the LED and to generate a single audible chime tone. These functions serve as an indication to the customer that the SKIS has been placed in its "Customer Learn" programming mode. See Sentry Key Immobilizer System Transponder Programming for more information on the "Customer Learn" programming mode.
For diagnosis or initialization of the SKIM and the PCM, a DRB III scan tool and the proper Body Diagnostic Procedures are required. The SKIM cannot be repaired, and if faulty or damaged, the unit must be replaced.
Sentry Key Immobilizer Transponder:
SENTRY KEY IMMOBILIZER TRANSPONDER
The Sentry Key Immobilizer System (SKIS) uses a transponder that is integral to each of three ignition key that are supplied with the vehicle when it is shipped from the factory. The transponder chip is insulated within a nylon mount inserted in the head of the key, and invisible beneath a molded rubber cap.
Each Sentry Key transponder has a unique transponder identification code programmed into it by the manufacturer. The Sentry Key Immobilizer Module (SKIM) has a unique "Secret Key" code programmed into it by the manufacturer. When a Sentry Key transponder is programmed into the memory of the SKIM, the SKIM learns the transponder identification code from the transponder and the transponder learns the "Secret Key" code from the SKIM. Each of these codes is stored within the transponder and in the nonvolatile memory of the SKIM. Therefore, blank keys for the SKIS must be programmed by and into the SKIM, in addition to being cut to match the mechanical coding of the ignition lock cylinder. See Sentry Key Immobilizer System Transponder Programming for more information.
The Sentry Key transponder cannot be repaired and, if faulty or damaged, it must be replaced.
The Sentry Key transponder is within the range of the SKIM transceiver antenna ring when it is inserted in the ignition lock cylinder. When the ignition switch is turned to the START or RUN positions, the SKIM transceiver issues a Radio Frequency (RF) signal that excites the transponder chip. The transponder chip responds by issuing an RF signal containing its transponder identification code and the "Secret Key" code. The SKIM transceiver compares the transponder codes with the codes stored in its memory to determine whether a valid key is in the ignition lock cylinder.
SENTRY KEY IMMOBILIZER SYSTEM INDICATOR LAMP
The Sentry Key Immobilizer System (SKIS) uses the Vehicle Theft Security System (VTSS) indicator LED to give an indication when the SKIS is faulty or when the vehicle has been immobilized due to the use of an invalid ignition key. The LED is controlled by the instrument cluster circuitry based upon messages received from the Sentry Key Immobilizer Module (SKIM) through the Body Control Module (BCM) on the Chrysler Collision Detection (CCD) data bus.
The SKIM sends messages to the instrument cluster, via the BCM, to turn the LED on for about three seconds when the ignition switch is turned to the ON position as a bulb test. After completion of the bulb test, the SKIM sends bus messages to keep the LED off for a duration of about one second. Then the SKIM sends messages to the instrument cluster circuitry to turn the LED on or off based upon the results of the SKIS self-tests. If the VTSS indicator LED comes on and stays on after the bulb test, it indicates that the SKIM has detected a system malfunction and/or that the SKIS has become inoperative. If the SKIM detects an invalid key when the ignition switch is turned to the ON position, it sends messages to the instrument cluster to flash the VTSS indicator LED.
The SKIM can also send messages to the instrument cluster to flash the LED and to generate a single audible chime tone. These functions serve as an indication to the customer that the SKIS has been placed in its "Customer Learn" programming mode. See Sentry Key Immobilizer System Transponder Programming for more information on the "Customer Learn" programming mode.
The VTSS indicator LED uses a replaceable Light Emitting Diode (LED) on the instrument cluster electronic circuit board. If the VTSS indicator LED comes on and stays on after the bulb test function, diagnosis of the SKIS should be performed with a DRB III scan tool and the proper Body Diagnostic Procedures.
TRIGGERING THE VTSS
Any of the following actions will trigger the system:
1. Opening any door.
2. Removing the deck lid lock cylinder.
3. Turning the ignition to the ON position.
Using the power door switch, ignition key or the Remote Keyless Entry (RKE) transmitter will arm the system.
CAUTION: The VTSS indicator LED will trigger and engine will continue to run if the vehicle is equipped with SKIS and the proper key is used to start the vehicle. This condition will occur if the VTSS has been triggered.
NOTE: The ignition switch can be turned to the accessory position without triggering alarm system.