Anti-Theft - Active
Anti-Theft - Active
COMPONENT LOCATIONS
NOTE: RHD (right-hand drive) installation shown, LHD (left-hand drive) installation similar
GENERAL
The active anti-theft system monitors the hinged panels for unauthorized opening. On some vehicles, the active anti-theft system also incorporates interior monitoring and vehicle tilt sensing functions. If an alarm event is detected, the active anti-theft system generates audible and visual alarm signals. The active anti-theft system is controlled by the GEM (generic electronic module) and is configured to automatically arm and disarm with operation of the CLS (central locking system).
The active anti-theft system incorporates:
- An alarm indicator.
- A BABUS.
- A volumetric sensor (if fitted).
- A tilt sensor (if fitted).
The active anti-theft system also uses:
- The GEM (generic electronic module).
- The hood, door and tailgate ajar switches.
ALARM INDICATOR
The alarm indicator is installed in the instrument cluster to provide a visual indication of the active anti-theft system status. Operation of the alarm indicator is controlled by a hardwired input from the GEM (generic electronic module), which pulls the input to ground to illuminate the alarm indicator.
Alarm Mode Alarm Indicator
Disarmed Off
Armed Flashes at 0.5 Hz (slow flashing)
Arming Rapid flashing for 10 seconds maximum, then begins flashing at 0.5 Hz.
Alarm triggered Rapid flashing for 5 minutes then continues flashing at 0.5 Hz.
Re-arming less than 10 seconds On for 1 second
after disarming
Disarming Off
Disarming after alarm Rapid flashing for 10 seconds then off
Emergency disarming On for 10 minutes
Vehicle locked (alarm not coded in GEM On for 10 seconds
(generic electronic module) )
Unauthorized engine start detected by Rapid flashing until PATS (passive anti-theft system) deactivated PATS (passive antitheft system)
BBUS
The BBUS is installed in the rear corner of the engine compartment, on the driver side, on a bracket attached to the front fender. In some markets, the BBUS is covered by a shield for added security. Depending on the GEM (generic electronic module) configuration, the BBUS can be used to produce the audio acknowledgment for arming and disarming of the active anti-theft system as well as the audio warning after an alarm has been triggered.
The BBUS is normally operated by a permanent battery feed from the CJB (central junction box). An integral 7.2 V rechargeable battery powers the BBUS if it is disconnected from the vehicle battery.
The BBUS sounds when it receives an alarm or acknowledgment signal from the GEM (generic electronic module). While the active anti-theft system is armed, the BBUS also monitors the battery power supply and the arm/disarm signal line from the GEM (generic electronic module), and operates the sounder if the battery power supply or the arm/disarm signal line is disconnected. The GEM (generic electronic module) arms and disarms the BBUS together with the rest of the active anti-theft system.
Once an alarm has been triggered, the BBUS cycles the sounder on for 30 seconds and off for 15 seconds, for 5 minutes or until it receives a disarm signal from the GEM (generic electronic module). If the alarm trigger is still present, the 5 minutes of on/off cycles is repeated a further 2 times. The alarm output from the BBUS is either a constant tone or a modulated tone, depending on the market. The continuous tone has a nominal value of 113 dBA when powered by the vehicle battery and 108 dBA when powered by the integral battery. The modulated tone has a nominal value of 109 dBA when powered by the vehicle battery and 104 dBA when powered by the integral battery.
VOLUMETRIC SENSOR (IF FITTED)
The volumetric sensor is installed behind openings in the rear interior lamp and monitors for intrusion into the passenger compartment when the alarm is armed.
The volumetric sensor consists of a microcontroller, two acoustic transmitters and two acoustic receivers. One transmitter/receiver pair faces forwards and one transmitter/receiver pair faces rearwards to ensure complete coverage of the passenger compartment. The front transmitter/receiver pair are in a rubber mounting attached to the microcontroller housing. The rear transmitter/receiver pair are in a remote rubber mounting and connected to the microcontroller housing by a four wire lead.
The volumetric sensor is powered by a permanent battery feed from the CJB (central junction box). The GEM (generic electronic module) activates and de-activates the volumetric sensor when it arms and disarms the active anti-theft system. When the volumetric sensor is active it outputs ultrasonic pulses from the transmitters and checks the echoes picked up by the receivers for changes to the passenger compartment profile. If it detects a change of profile indicating movement in the passenger compartment the volumetric sensor reports the alarm to the GEM (generic electronic module).
Each time the volumetric sensor is activated it performs a self test. If there are no faults the volumetric sensor sends an acknowledgment signal to the GEM (generic electronic module). If the GEM (generic electronic module) does not receive the acknowledgment signal it de-activates the volumetric sensor.
TILT SENSOR (IF FITTED)
The tilt sensor monitors for changes of vehicle attitude while the alarm is armed. The tilt sensor is installed under the front passenger seat in the GEM (generic electronic module) bracket.
The tilt sensor incorporates a two axis sensor controlled by a microprocessor. A permanent battery feed from the CJB (central junction box) powers the tilt sensor. The GEM (generic electronic module) activates and de-activates the tilt sensor when it arms and disarms the active anti-theft system. The tilt sensor receives activation and de-activation signals from the GEM (generic electronic module).
The tilt sensor measures the longitudinal and transverse angles of the vehicle over a range of ±16 degrees from the horizontal. When the tilt sensor is activated, it stores the current angles in memory. If the vehicle changes attitude in either direction by more than the limit the tilt sensor sends an alarm signal to the GEM (generic electronic module), which triggers the BBUS. After an alarm, the alarm limit is reduced to make the system more sensitive to any further change of attitude.
Each time the tilt sensor is activated it performs a self test. If there are no faults the tilt sensor sends an acknowledgment signal to the GEM (generic electronic module). If the GEM (generic electronic module) does not receive the acknowledgment signal it de-activates the tilt sensor.
SYSTEM OPERATION
The active anti-theft system arms and disarms in conjunction with the locking and unlocking of the CLS. Depending on the configuration of the GEM (generic electronic module), the active anti-theft system can be armed and disarmed when the locking system is activated with the driver door lock or the remote handset, or only with the remote handset. Visual and audible confirmation of the active anti-theft system arming and disarming, using the direction indicators and the BBUS, are also configurable in the GEM (generic electronic module).
When the vehicle is superlocked, the GEM (generic electronic module) sends an arming signal to the tilt sensor, the BBUS and the volumetric sensor. If the GEM (generic electronic module) does not receive an acknowledgment signal from the tilt sensor and the volumetric sensor within 1 second, the GEM (generic electronic module) disables the associated alarm feature for the remainder of the armed cycle.
If the GEM (generic electronic module) detects two superlocking signals within 10 seconds, it disables volumetric sensing and tilt sensing. This feature prevents accidental triggering of the active anti-theft system during transportation of the vehicle or if a pet is left in the vehicle.
Perimetric Sensing
When the active anti-theft system arms, the GEM (generic electronic module) waits for 3 seconds before it begins monitoring the door status switches and the bonnet switch for perimetric sensing. If a door or the bonnet have been left open, the GEM (generic electronic module) indicates this by flashing the alarm LED (light emitting diode) for approximately 10 seconds. The input from the open switch is ignored until 3 seconds after it changes to the closed state.
Volumetric Sensing
The GEM (generic electronic module) begins volumetric sensing 30 seconds after receipt of the superlock signal, the last door closes, or convenience closing stops, whichever occurs last.
If the alarm has been triggered, the GEM (generic electronic module) will ignore further volumetric sensor signals for the duration of the alarm. The GEM (generic electronic module) resumes volumetric sensing 30 seconds after the alarm has stopped sounding.
Volumetric sensing and tilt sensing are disabled if the GEM (generic electronic module) receives a tail door open signal from the ignition key/remote handset. The GEM (generic electronic module) resumes volumetric sensing and tilt sensing 30 seconds after the upper tail door closes again.
Emergency Disarming
If the alarm has been triggered and cannot be disarmed with the driver door lock or the ignition key/remote handset, it can be disarmed with the ignition switch as follows:
- Use the ignition key to unlock the driver door.
- Sit in the vehicle and ensure all the doors are closed.
- While the BBUS is still sounding, put the ignition key in the ignition switch and turn it to position I. The alarm indicator stays on instead of flashing.
- After 10 minutes, the BBUS stops sounding, the alarm indicator goes off, the locking system unlocks and the PATS (passive anti-theft system) is made inactive.
Emergency disarming is configurable in the GEM (generic electronic module).
CONTROL DIAGRAM
NOTE: A = Hardwired connection; B = K bus; C = Diagnostic DS2 bus; M = P bus
