Vehicle Theft Alarm: Notes

1.	Refer to AJAR SWITCHES .
2.	Refer to BODY CONTROL MODULE .
3.	Refer to INSTRUMENT PANEL CLUSTER  Security Indicator.
4.	Refer to IGNITION NODE MODULE . Refer to KEYLESS IGNITION NODE .
5.	Refer to LOW FREQUENCY ANTENNA .
6.	Refer to RADIO FREQUENCY HUB .
7.	Refer to SENTRY KEY TRANSPONDER .

The VTA is designed to provide either active or passive perimeter protection of the vehicle by monitoring the vehicle doors, the ignition status, the liftgate and the power lock switches. In vehicles built for certain markets where it is required equipment, or those equipped with the optional remote start system (North America Free Trade Agreement/NAFTA market only), the BCM also monitors an input from the hood ajar switch integral to the hood latch. If the VTA system detects any attempt to compromise a monitored vehicle system or feature, the vehicle horn is pulsed as an audible deterrent and certain exterior lamps are flashed as a visual deterrent.

The BCM, the IPC and the RFH each contain a microcontroller and programming that allow them to communicate with each other and other electronic modules in the vehicle using the CAN-C data bus. In addition, in vehicles equipped with PEKG, the RFH and the BCM communicate with each other using a Local Interface Network (LIN) data bus. Refer to COMMUNICATION, DESCRIPTION AND OPERATION .

OPERATION 

The BCM includes the logic and control circuits for the VTA. Each of the ajar switches provides hard wired inputs to the BCM, while the BCM provides control outputs to the vehicle horns and lighting systems. In vehicles not equipped with the optional PEKG system, the BCM also monitors the status of the ignition switch through a hard wired input. In vehicles equipped with the PEKG system, the RFH monitors the status of the KIN through a private Security K-line data bus and relays this information to the BCM as electronic messages transmitted over the CAN-C data bus.

OPERATING MODES 

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

• Enabling  - The BCM and the RFH must have the VTA function electronically enabled in order for the VTA to perform as designed. The BCM stores and compares vehicle configuration data with other Electronic Control Units (ECU) in the vehicle, including the RFH. This process is referred to as Programming Of Configuration of Systems Integrated (PROCSI) (also known as PROXI). If a configuration mismatch is detected, the BCM sets a Diagnostic Trouble Code (DTC). A configuration mismatch will require the performance of a Restore BCM PROXI Configuration routine, or a PROXI Configuration Alignment routine using a diagnostic scan tool.
• Alarm  - The VTA alarm output 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 turn signal lamps, while the audible output will be either a pulsing of the horn or, if the vehicle is so equipped, the siren. For vehicles with the base version of the VTA, the inputs that will trigger the alarm include a change in the status of the ignition, the door ajar switches, the liftgate ajar switch and, in vehicles built for certain markets where they are required, the hood ajar switch. In vehicles with the premium version of the VTA, the inputs that will trigger the alarm also include any movement detected within the vehicle passenger compartment, or a change in the vehicle pitch or roll of greater than about 0.5 degrees.
• Arming  - Arming of the VTA occurs when the vehicle is exited and the key is removed from the ignition switch (without PEKG) and the switch status is OFF or the status of the KIN (with PEKG) is OFF, the exterior lighting is turned Off, then the Lock button on the Remote Keyless Entry (RKE) transmitter is depressed or the Lock button on the Passive Entry (PE) is pressed to lock the vehicle. For active arming to occur, the doors and the liftgate must be closed and the status of the ignition switch or the KIN must be Off when the RKE transmitter or PE handle Lock button is depressed. Arming will not occur if a key is in the ignition switch lock cylinder or a FOB with Integrated Key (FOBIK) is within the vehicle interior.

  Pre-arming of the VTA is initiated when a door or the deck lid is open when the vehicle is locked using a power door lock switch or when the RKE Lock button is pressed. Pre-arming will not occur if a FOBIK is within the vehicle interior. 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 arming sequence, the security indicator in the IPC will flash rapidly for about 16 seconds. This indicates that VTA arming is in progress. If the status of the ignition switch or KIN changes, if a door or the liftgate is unlocked or opened by any means, 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.

  The VTA arming sequence will occur regardless of whether a door or the liftgate is open or closed, but the security indicator will illuminate solid and the open door or the liftgate will not be protected unless the door or the liftgate is closed when the VTA arming sequence first begins.

  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 security indicator will illuminate solid and the engine compartment will not be protected unless the hood is closed when the VTA arming sequence first 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 switch from solid to flashing. Once the arming process is successfully completed, the security indicator will flash at a slower rate, indicating that the VTA is armed.

• Disarming  - Passive disarming of the VTA occurs when the vehicle is unlocked by depressing the Unlock button of the RKE transmitter. Once the alarm has been activated, this disarming method will also deactivate the alarm. Unlocking a door with a key will not  disarm the VTA or deactivate the alarm. On vehicles equipped with PE, if one of the valid FOBIK units is located outside the vehicle and within 1.5 meters (5 feet) of the driver or passenger front door handles, grab the Passive Entry (PE) handle and enter the vehicle, then press the Start/Stop Button (SSB) to transition the ignition status to ON. This requires at least one valid FOBIK be located within the passenger compartment of the vehicle.
• 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 armed 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 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 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.
• Tamper Alert  - The VTA tamper alert feature will illuminate an icon in the IPC when the ignition first transitions to ON 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.