Vehicle Theft Security System - Operation

OPERATION

The Vehicle Theft Security System (VTSS) is divided into two basic subsystems: Vehicle Theft Alarm (VTA) and Sentry Key Immobilizer System (SKIS). Following are paragraphs that briefly describe the operation of each of these two subsystems.

VEHICLE THEFT ALARM

The Totally Integrated Power Module (TIPM) is used on this vehicle to control and integrate many of the functions and features included in the Vehicle Theft Alarm (VTA). In the VTA system, the TIPM receives inputs indicating the status of the door ajar switches, the ignition switch, the liftgate ajar switch, and the power lock switches. In vehicles built for certain export markets where it is required, the hood ajar switch provides a hard-wired input to the TIPM. The TIPM processes the information from all of these inputs and sends the appropriate electronic messages over the CAN data bus. The TIPM internally controls the output to the hazard warning lamps and sends a control output to energize or de-energize the horn relay as appropriate.

The hard-wired circuits between components related to the VTA system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, procedures for proper wire and connector repair, details of wire harness routing and retention, connector pin-out information, and location views for the various wire harness connectors, splices, and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the VTA system or the electronic controls or communication between modules and devices that provide some features of the VTA system. The most reliable, efficient, and accurate means to diagnose the VTA system or the electronic controls and communication related to VTA system operation requires the use of a diagnostic scan tool. See the Vehicle Theft Security System menu item on the scan tool. Refer to the appropriate diagnostic information.

Following are paragraphs that briefly describe the operation of each of the VTA features.

ENABLING

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

ARMING

Passive arming of the VTA occurs when the vehicle is exited with the FOB with Integrated Key (FOBIK) removed from the ignition switch, the headlamps are turned OFF, and the doors are locked while they are open using the power lock switch. Active arming occurs when the LOCK button on the Remote Keyless Entry (RKE) transmitter integral to the FOBIK is depressed to lock the vehicle. For active arming to occur, the doors, and the liftgate must be closed and the ignition switch must be in the OFF position when the FOBIK RKE transmitter LOCK button is depressed. The power lock switch will not function if the FOBIK is in the ignition switch or the headlamps are turned ON with the driver side front door open.

Pre-arming of the VTA is initiated when a door or the liftgate is open when the vehicle is locked using a power door lock switch or when the RKE transmitter LOCK button is depressed. Pre-arming will not occur if the FOBIK is in the ignition switch or the headlamps are turned ON with the driver side front door open. When the VTA is pre-armed, the arming sequence is delayed until all of the doors and the liftgate have been closed. The VTA will remain in pre-armed mode for up to 16 seconds after all doors and the liftgate have been closed.

Once the VTA begins the passive or active arming sequence, the security indicator in the instrument cluster will flash rapidly for about 16 seconds. This indicates that VTA arming is in progress. If the ignition switch is turned to the ON position, if a door or the liftgate is unlocked and opened by any means, or the RKE PANIC button (if equipped) is depressed during the 16 second arming process, the security indicator will stop flashing and the arming process will abort. Once the arming sequence is successfully completed, the security indicator will flash at a slower rate, indicating that the VTA is armed.

On vehicles equipped with the hood ajar switch, the VTA arming sequence will occur regardless of whether the hood is open or closed, but the underhood area will not be protected unless the hood is closed when the VTA arming sequence begins. Also, if the status of the hood ajar switch changes from open to closed during the 16 second arming process, the security indicator will stop flashing and the VTA arming sequence will abort. Once the arming process is successfully completed, the security indicator will flash at a slower rate, indicating that the VTA is armed.

DISARMING

For vehicles built for the North American market, passive disarming of the VTA occurs by inserting a valid Sentry Key Immobilizer System (SKIS) FOBIK into the ignition switch. Active disarming of the VTA for all markets occurs when the vehicle is unlocked by depressing the UNLOCK button of the FOBIK RKE transmitter. Once the alarm has been activated, either disarming method will also deactivate the alarm. Depressing the PANIC button (if equipped) on the FOBIK RKE transmitter will not disarm the VTA.

POWER-UP MODE

When the armed VTA 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 VTA 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 VTA will be armed until the technician or vehicle operator has actively or passively disarmed the alarm system. If the VTA 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.

ALARM

The VTA alarm output varies by the version of the VTA with which the vehicle is equipped. In all cases, the alarm provides both visual and audible outputs; however, the time intervals of these outputs vary by the requirements of the market for which the vehicle is manufactured. In all cases, the visual output will be a flashing ON and OFF of the exterior lamps. For vehicles equipped with the North American or the export base version of the VTA, the audible output will be a pulsing of the horn. See the owner's manual in the vehicle glove box for details of the alarm output requirements of the specific market for which the vehicle was manufactured. The inputs that will trigger the alarm include the door ajar switches, the liftgate ajar switch, and in vehicles built for certain markets where required, the hood ajar switch.

TAMPER ALERT

The VTA tamper alert feature will pulse the horn three times upon VTA disarming if the alarm was triggered and has since timed out or if the battery has been disconnected and reconnected. This feature alerts the vehicle operator that the VTA alarm was activated while the vehicle was unattended.

SENTRY KEY IMMOBILIZER SYSTEM

The Sentry Key Immobilizer System (SKIS) is designed to provide passive protection against unauthorized vehicle use by disabling the engine whenever any method other than a valid Sentry Key FOB with Integrated Key (FOBIK) is used to start the vehicle. The SKIS is considered a passive protection system, because it is always active when the ignition system is energized and it does not require any customer intervention. The SKIS uses Low Frequency (LF) communication to obtain confirmation that the FOBIK in the ignition switch is valid for operating the vehicle. The microprocessor-based SKIS hardware and software also uses electronic messages to communicate with other electronic modules in the vehicle over the Controller Area Network (CAN) data bus. Communication - Operation.

Pre-programmed Sentry Key FOBIK transponders are provided with the vehicle from the factory. Each Wireless Ignition Node (WIN) will recognize a maximum of eight Sentry Key FOBIK transponders. If the customer would like additional FOBIKs, other than those provided with the vehicle, they may be purchased from any authorized dealer. These additional FOBIKs must be programmed to the WIN in the vehicle in order for the system to recognize them as valid. This can be done by the dealer using a diagnostic scan tool, or if Customer Learn programming is an available SKIS feature in the market where the vehicle was purchased, the customer can program the additional FOBIKs, as long as at least two valid Sentry Key FOBIKs are already available. .

The WIN performs a self-test of the SKIS each time the ignition switch is turned to the ON position, and will store fault information in the form of a Diagnostic Trouble Code (DTC) if a system malfunction is detected. The WIN will also send an electronic message to the instrument cluster if a fault is detected, and the instrument cluster illuminates the security indicator.

The hard-wired circuits between components related to the SKIS may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, procedures for proper wire and connector repair, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the SKIS or the electronic controls or communication between other modules and devices that provide some features of the SKIS. The most reliable, efficient, and accurate means to diagnose the SKIS or the electronic controls and communication related to SKIS operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.