Antitheft and Alarm Systems: Description and Operation

VEHICLE THEFT SECURITY

DESCRIPTION




The Vehicle Theft Security System (VTSS) is an available factory-installed option on this vehicle. The VTSS is comprised of two primary subsystems: Vehicle Theft Alarm (VTA) and Sentry Key Immobilizer System (SKIS). The VTA is an active system that provides visual and audible responses as deterrents to and warnings of unauthorized vehicle tampering. The SKIS is a passive system that effectively immobilizes the vehicle against unauthorized operation. Following are paragraphs which describe these subsystems of the VTSS.

Certain functions and features of the VTSS rely upon resources shared with or controlled by other electronic modules in the vehicle over the Controller Area Network (CAN) data bus. Other modules that may affect VTSS operation are:
- Driver Memory Mirror Module - Driver front door ajar switch and power lock switch status.
- Electromechanical Instrument Cluster (EMIC) - Also sometimes referred to as the Cab Compartment Node (CCN). Driver and passenger rear door, liftgate and flip-up glass ajar switch status. Flip-up glass release switch status. VTA system logic. Security indicator control.
- Front Control Module (FCM) - Hood ajar switch status. Exterior lighting system and horn system control.
- Passenger Memory Mirror Module - Passenger front door ajar switch and power lock switch status.
- Powertrain Control Module (PCM) - SKIS engine control logic.
- Steering Control Module (SCM) - Ignition switch status.

Except for the Sentry Key transponders, which rely upon Radio Frequency (RF) communication, hard wired circuitry connects the VTA and SKIS components to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the SKIS components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

VEHICLE THEFT ALARM
The VTA is available in two different configurations for this vehicle: One configuration is designed for vehicles manufactured for sale in North America; while, the other configuration is designed for vehicles manufactured for sale in markets outside of North America, also referred to as export markets within the context. In addition, the VTA for export is available in two versions: base and premium. All vehicles equipped with VTA are also equipped with the Remote Keyless Entry (RKE) system and the Sentry Key Immobilizer System (SKIS), regardless of their market destination.

The North American and export base version of the VTA system provide perimeter vehicle protection by monitoring the vehicle doors, the ignition switch, the liftgate, the liftgate flip-up glass and, for vehicles built for certain markets where it is required equipment, the hood. If unauthorized vehicle use or tampering is detected, these systems respond by pulsing the vehicle horn as an audible deterrent and flashing certain exterior lamps as a visual deterrent.

The export premium version of the VTA system is only available in vehicles manufactured for sale in certain markets where it is required equipment. The export premium version of the VTA provides the same perimeter protection features as the base version, but adds interior vehicle intrusion protection. The export premium VTA also replaces the pulsing horn feature of the base version with an alarm siren as the audible deterrent, while retaining the flashing exterior lamps as the visual deterrent.

The VTA includes the following major components, which are described in further detail:
- Door Ajar Switches (8) - A door ajar switch is integral to the door latch mechanism of each front and rear door.
- Flip-Up Glass Ajar Switch (11) - A flip-up glass ajar switch is integral to the liftgate flip-up glass latch, located on the liftgate below the glass opening near the center.
- Hood Ajar Switch (2) - A hood ajar switch is located in a bracket on the left inner fender side shield of vehicles built for sale in certain export markets where it is required equipment.
- Intrusion Module (9) - An intrusion module is located in a cavity on the right side of the intermediate step assembly under the right outboard second row seat cushion in the passenger compartment of vehicles built for sale in certain export markets where it is required equipment.
- Intrusion Sensor Receiver (6) - An intrusion sensor receiver is located in a bracket on the left rear corner of the overhead console above the headliner in the passenger compartment of vehicles built for sale in certain export markets where it is required equipment.
- Intrusion Sensor Transmitter (7) - An intrusion sensor transmitter is located in a bracket behind the left rear corner of the headliner in the passenger compartment of vehicles built for sale in certain export markets where it is required equipment.
- Liftgate Ajar Switch (10) - A liftgate ajar switch is integral to the latch for the liftgate in the vehicle.
- Security Indicator (4) - A security indicator is integral to the Electromechanical Instrument Cluster (EMIC).
- Siren (1) - An alarm siren is located in a hollow behind the right end of the front frame crossmember outboard of the right front frame rail. A single screw secures the mounting bracket to the right end of the front crossmember of vehicles built for sale in certain export markets where it is required equipment.

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) is used on this vehicle to control and integrate many of the functions and features included in the Vehicle Theft Alarm (VTA). The EMIC is also sometimes referred to as the Cab Compartment Node (CCN). In the VTA system, the EMIC/CCN 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 processes 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 and components of the VTA may be diagnosed and tested using conventional diagnostic tools and procedures. However, conventional diagnostic methods may not prove conclusive in the diagnosis of the EMIC/CCN, the FCM, the intrusion module, the CAN data bus or the electronic message inputs and outputs used to provide the electronic features of the VTA. The most reliable, efficient, and accurate means to diagnose the EMIC/ CCN, the FCM, the intrusion module, the CAN data bus, and the electronic message inputs for the VTA requires the use of a diagnostic scan tool. See the Vehicle Theft Security System menu item on the scan tool.

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.

ARMING
Passive arming of the VTA occurs when the vehicle is exited with the key 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 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 RKE transmitter LOCK button is depressed. The power lock switch will not function if the key 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 key 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) key into the ignition lock cylinder 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 RKE transmitter. Once the alarm has been activated, either disarming method will also deactivate the alarm. Depressing the PANIC button (if equipped) on the 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 three 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. 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 can be diagnosed, and any stored DTC can be retrieved using a diagnostic scan tool.