Vehicle Theft Security System (Vtss)
INTRODUCTIONThe Vehicle Theft/Security System (VTSS) is designed to protect against whole vehicle theft. The system monitors vehicle doors, hood, trunk key cylinder, and ignition for unauthorized operation.
The VTSS activates:
- Sounding of the horn.
- Flashing of the park lamps.
- Flashing of the headlamps.
The RKE Module has three modes of operation including customer usage mode, dealer lot storage mode, and shipping mode. The customer usage mode provides full functionality of the module and is the mode in which the RKE Module should be operating when used by the customer. Dealer lot storage mode and shipping mode are reduced power modes meant to extend vehicle battery life during shipping and storage in the dealer lot. Dealer lot storage mode provides limited VTSS and power door lock functions, and disables the Remote Keyless Entry (RKE) functions. This mode is intended to be used when the vehicle is on the dealer lot to provide VTSS coverage of the vehicle while minimizing battery drain. Shipping mode disables all normal functions of the module with the exception of communications over the vehicle's PCI bus, and is intended to be used when the vehicle is shipped from the assembly plant. The dealer must remove the module from shipping mode and place it into either the dealer lot storage or customer usage modes of operation.
NOTE: The dealer must remove the module from "Ship Mode" and place the RKE Module into either the "Dealer Lot" storage or "Customer Usage" modes of operation after receiving the vehicle from the assembly plant. Refer to Switching Operating Modes/configuring a New Module under Service Procedures.
VEHICLE THEFT/SECURITY SYSTEM (VTSS)
In the customer usage mode of operation, the system is armed when the vehicle is locked using the:
- Power door lock switches.
- Remote Keyless Entry (RKE) transmitter.
After the vehicle is locked and the last door is closed, the circular red VTSS indicator in the instrument cluster will flash quickly for 16 seconds, indicating that arming is in progress. If no monitored systems are activated during this period (excluding the hood and trunk key cylinder), the system will arm. After 16 seconds, the LED will continue to flash at a slower rate indicating the system is armed.
If the hood ajar switch and/or trunk key cylinder switch(s) are not sensed by the system, the indicator LED will remain lit during the arming process, although the system will still arm. If the VTSS indicator does not illuminate at all upon door closing it indicates that the system is not arming.
VTSS disarming occurs upon normal vehicle entry by unlocking either door via the key cylinders or RKE transmitter, or by starting the vehicle with a valid Sentry Key. This disarming will also halt the alarm once it has been activated.
A tamper alert exists to notify the driver that the system had been activated. This alert consists of 3 horn pulses when the vehicle is disarmed.
The VTSS will not arm by mechanically locking the vehicle doors. This will manually override the system.
In the dealer lot storage mode of operation, all of the above descriptions of the VTSS are true with the following exceptions:
- Remote Keyless Entry functions are disabled, and cannot be used for arming/disarming the VTSS.
- The VTSS indicator is non-operational.
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 while the system is armed. The primary components of this system are the Sentry Key Immobilizer Module (SKIM), the Sentry Key transponder, the Vehicle Theft/Security System (VTSS) indicator LED, and the 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 (DTC's) if a system malfunction is detected. The SKIS can be diagnosed, and any stored DTC can be retrieved using a DRB III(R) scan tool as described in the proper Body Diagnostic Procedures.
SENTRY KEY IMMOBILIZER MODULE (SKIM)
Sentry Key Immobilizer (SKIM) Location:
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 Programmable Communication Interface (PCI) bus network with the Powertrain Control Module (PCM), the instrument cluster and/or the DRB III(R) 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 eight millimeters (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 PCI 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 PCI 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 PCI 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(R) 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 SYSTEM 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 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.
The Sentry Key transponder cannot be repaired and, if faulty or damaged, it must be replaced.
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 Programmable Communication Interface (PCI) 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 PCI 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(R) scan tool and the proper Body Diagnostic Procedures.
TRIGGERING THE VTSS
After the VTSS is armed, any of the following will trigger the system:
- Opening any door.
- Opening the hood.
- Removing the trunk lock cylinder.
- Turning the ignition to the RUN/START position with an invalid Sentry Key.
NOTE: The ignition switch can be turned to the accessory position without triggering the alarm system.