Antitheft and Alarm Systems: Description and Operation
The main function of the system is to offer easy to use remote locking and unlocking of the vehicle without having to actively select the alarm function.
COMPONENT LOCATION
1. Electronic control unit (ECU) and relays Passenger footwell
2. Bonnet switch RH engine bay
3. Door switches
4. Alarm sounder RH engine bay
5. Light emitting diode (LED) Dash panel
6. Ultrasonic unit Roof map pocket
7. Lock barrel, sill buttons
8. Handset transmitter
9. Aerial 'A' post, passenger side.
Perimetric protection
Using the key in the correct sequence will turn on and off perimetric protection only. When fully perimetrically armed, all doors, and bonnet [hood] are protected against unauthorized access. If the door key is used in the normal manner the driver will be unaware of the door key sequence. The time taken to lock or unlock with the key must be less than 5 seconds. To prevent unauthorized tampering, the alarm will sound if the key is held in the unlocked position for longer than 5 seconds when armed. Cranking is disabled when perimetric protection is armed.
NOTE: When key is turned left or right the keyswitch input will be activated, in conjunction with the sill button switch when links are operated.
Volumetric protection
Using the handset transmitter will turn on and off volumetric protection. In volumetric mode the vehicle interior is protected using the ultrasonic sensor. Using the handset also arms and disarms the vehicle perimetrically. Cranking is disabled when volumetric and perimetric protection is armed.
NOTE: If armed volumetrically the vehicle CANNOT be disarmed using the key.
Alarm horn
When an intrusion is detected the alarm horn will sound intermittently (Switzerland and Denmark continuous horn sound) and the hazard lights flash (where territorial regulations allow) for 30 seconds. The alarm must be retriggered before alarm horn will sound again.
Vehicle status indication
Vehicle status is indicated by up to three devices: (a) alarm horn, (b) hazard lights, (c) dash board LED. When the vehicle arms in either mode the hazard lights will flash three times and the LED will flash rapidly for 10 seconds. LED will then flash at a slower rate while vehicle is armed. When the vehicle disarms, hazard lights will flash once and LED will extinguish. If LED remains lit, it indicates that the alarm has been triggered. Turning on ignition or arming the alarm will extinguish LED. The LED will give a long pulse flash to indicate the ultrasonic unit being activated.
Central locking
Central locking is controlled by the alarm ECU and may be operated by the key, sill button(s) or handset. The system works on both front doors on four door vehicles or driver's door on two door vehicles.
NOTE: The central door locking system will shut down for a short period after more than 15 consecutive operations.
Inertia switch
An inertia switch is incorporated in the alarm system ECU. If ignition is on and the vehicle receives an impact sufficient to activate the inertia switch, the ECU will signal to unlock central locking actuators and flash hazard lights. Central locking will remain disabled for 30 seconds. To reset turn ignition off and then on after the 30 seconds period has elapsed.
Ultrasonic unit
The unit operates by emitting an air pressure carrier wave and receiving the wave back. Any disturbance within the vehicle which disturbs the wave will be detected, triggering the alarm.
When the volumetric sensor is activated it monitors movement within the vehicle for 15 seconds before detecting and responding to intrusions. If the sensor detects movement within the vehicle it delays arming until a 15 seconds quiet period has elapsed. If continuous movement is detected the alarm will not arm volumetrically.
Radio frequency system
The RF system uses four frequencies according to market. If the coaxial aerial is not fitted system performance will be impaired. Both ECU and handset have a colour coded label.
Frequency Color Territory
ECU/Handset
433.92MHz Blue/black UK, Ireland
224.5 MHz Yellow/yellow France
433.92 MHz Blue/Purple Germany
433.92 MHz Blue/blue Europe, not France, Switzerland, Italy, Denmark, Germany
433.92 MHz White/Blue Switzerland, Denmark
315.0 MHz Green/green Rest of world, Italy, Australia
315.0 MHz Orange/Green Gulf, Japan
Partially armed mode
If a door, tailgate or bonnet [hood] is left open when the system is armed, the LED will not light for 10 seconds indicating a mislock condition. Hazard lights will not flash. If an open door or tailgate is causing the mislock, the starter motor is disabled. The alarm will sound if ignition is turned to start position. If an open bonnet [hood] is causing the mislock the starter motor is disabled. The alarm will arm the volumetric part of the system. If the door tailgate or bonnet [hood] is subsequently closed, after a 5 second delay, the doors will unlock and immediately lock and the system will fully arm.
Handset transmitter
The handset LED will give one short flash when button is pressed momentarily.
If button is held down the LED will light again after 2 seconds for 2 seconds, and extinguish until button is released and repressed. The handset contains unique information distinguishing it from other transmitters. It also contains a set of 'random' rolling codes programmed into the ECU before leaving the factory. Each time the handset is pressed a different code is transmitted to the ECU.
If handset is operated more than four times outside the vehicle range (6 meters) or power supply is removed, it will be necessary to re-sychronize handset and the ECU by pressing the handset three times within range and within 5 seconds.
NOTE: If both handsets are lost or damaged when system is armed it will be necessary to fit a new ECU with two matching handsets.
Handset batteries
If handset LED flashes continuously when button is pressed, the batteries need replacing. The hazard lights will flash one 3 seconds pulse, instead of three times upon arming vehicle.
Power up mode
The alarm system always remembers the state it was left in when power was removed. If the alarm powers up in an armed state and is subsequently triggered it will give a warning that it will fully trigger unless disarmed. This warning consists of short horn pulses every two seconds for 15 seconds.
New born mode
When the ECU is first produced, it will be in its 'new born' mode. In this mode it will respond to any remote of the right frequency. This mode will be cancelled when the ECU has received ten valid handset signals without power interruption.
Engine cranking
It is only possible to crank the engine when ignition is ON and alarm disabled.