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 ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) 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 EMIC receives inputs indicating the status of the door ajar switches, the ignition switch, the liftgate ajar switch, the flip-up glass 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 Front Control Module (FCM) and both the FCM and the intrusion module provide electronic message inputs to the EMIC over the Controller Area Network (CAN) data bus. The EMIC will process the information from all of these inputs, internally controls the security indicator as appropriate, and sends electronic messages to the FCM over the CAN data bus. The FCM internally controls the output to the hazard warning lamps and sends a control output to energize or de-energize the horn relay as appropriate. On vehicles with an intrusion module, the horn output of the FCM is replaced by an output of the siren module that is controlled by the intrusion module.

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, proper wire and connector repair procedures, 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. See the owner's manual in the vehicle glove box for more information on the features, use and operation of the VTA.

ENABLING

The EMIC must have the VTA function electronically enabled in order for the VTA to perform as designed. The logic in the EMIC keeps its VTA function dormant until it is enabled using a diagnostic scan tool. The VTA function of the EMIC is enabled on vehicles equipped with the VTA option at the factory, but a service replacement EMIC 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, the liftgate and the flip-up glass 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, the liftgate or the flip-up glass 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, the liftgate and the flip-up glass have been closed. The VTA will remain in pre-armed mode for up to 16 seconds after all doors, the liftgate and the flip-up glass 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 or by turning the ignition switch to the ON position. 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. For vehicles with the export premium version of the VTA, the audible output will be a cycling of the alarm siren. 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, the flip-up glass ajar switch, and in vehicles built for certain markets where they are required, the hood ajar switch and the intrusion module.

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.

INTRUSION ALARM

The intrusion alarm is an exclusive feature of the export premium version of the VTA, which is only available in certain markets where it is required. When the VTA is armed, the intrusion module uses a hard wired outputs to control an ultrasonic transmitter and receiver which allows the module to monitor the interior of the vehicle for movement. If motion is detected, the intrusion module sends an electronic message to the EMIC and the FCM over the CAN data bus to invoke the visual alarm features, and sends an electronic message to the alarm siren in the engine compartment over a dedicated serial bus to invoke the audible alarm feature.

The motion detect feature of the intrusion module can be disabled by depressing the LOCK button on the RKE transmitter 3 times within 15 seconds during VTA arming, while the security indicator is still flashing rapidly. The VTA provides a single short siren chirp as an audible confirmation that the motion detect disable request has been received.

The intrusion module must be electronically enabled in order for the intrusion alarm to perform as designed. The intrusion alarm function of the module is enabled on vehicles equipped with this option at the factory, but a service replacement module must be configured and enabled by the dealer using a diagnostic scan tool. Refer to the appropriate diagnostic information. The intrusion module monitors the conditions of the transmitter and receiver sensors as well as the siren, and will store fault information in the form of a Diagnostic Trouble Code (DTC) if a system malfunction is detected. The intrusion module may be diagnosed, and any stored DTC can be retrieved using a diagnostic scan tool. Refer to the appropriate diagnostic information.

SENTRY KEY IMMOBILIZER SYSTEM

The Sentry Key Immobilizer System (SKIS) is designed to provide passive protection against unauthorized vehicle use by disabling the engine after about two seconds of running, 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 does not require any customer intervention. The SKIS uses Low Frequency (LF) Radio Frequency (RF) 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 .

In vehicles equipped with an export premium version of the VTA, the SKIS also controls an electronic shaft lock module on the steering column that locks the steering shaft from rotation unless a valid FOBIK is detected in the ignition lock cylinder. The WIN communicates with the shaft lock module over a dedicated Local Interface Network (LIN) data bus to monitor and control the shaft lock function.

The WIN performs a self-test of the SKIS and the shaft lock module 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 or displays a textual SHAFT LOCK ERROR message in the reconfigurable dot matrix display of the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) as appropriate.

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, proper wire and connector repair procedures, 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.