Workshop Manuals Factory service & repair Land Rover
01 Introduction02 General information03 General data04 Identification numbers05 Torque wrench settings06 Lifting and towing07 Capacities, fluids and lubricants08 Maintenance09 Engine - Td510 Engine - V811 Emission control - Td512 Emission control - V813 Engine management system - Td514 Engine management system - V815 Fuel delivery system - Td516 Fuel delivery system - V817 Cooling system - Td518 Cooling system - V819 Manifolds and exhaust systems - Td520 Manifolds and exhaust systems - V821 Clutch - Td522 Clutch - V823 Manual gearbox - R38024 Transfer box - LT230SE25 Automatic gearbox - ZF4HP22/2426 Propeller shafts27 Rear axle28 Front axle29 Steering30 Front suspension31 Rear suspension32 Brakes33 Restraint systems34 Doors35 Exterior fittings36 Interior trim components37 Screens38 Seats39 Sunroof40 Chassis and body dimensions41 Panel repairs42 Body sealing materials43 Corrosion prevention and sealing44 Painting45 Heating and ventilation46 Air conditioning47 Wipers and washers48 Charging and starting49 Lighting50 Body control unit51 Alarm system and horn52 Windows53 In car entertainment54 Harnesses55 Driving aids56 Navigation system57 Instruments
Land Rover Discovery II (UK)51 · Alarm system and horn
51 · Electrical

Configurable system functions (Alarm system and horn) (page 2 of 7)

Make
Land Rover
Model
Discovery II (UK)
Section
Description and operation
Alarm system and hornConfigurable system functions · page 2 of 7

Perimetric alarm The perimetric alarm is used by the BCU to detect unauthorised opening of a door or hinged panel. Switches incorporated into the door latch assemblies and the bonnet determine the state of the panels.

There are two perimetric alarm configurations: l Alarm not active. l Alarm active.

Arming: To arm the perimetric alarm, press the lock button on the handset or lock the vehicle using the key in the driver's door. Once the alarm has been set, the BCU monitors the state of the doors and the bonnet.

In order to arm the perimetric alarm the following conditions must be met: l Drivers door closed. l Key not inserted in ignition switch. l Fuel cut-off switch not tripped.

Disarming: To prevent the alarm from triggering when entering the vehicle, the alarm system must be disarmed with the key or the handset.

There are two perimetric alarm disarming configurations: l Always disarm with key. l Only disarm with key if locked with key.

The perimetric alarm can be disarmed by unlocking the vehicle with the handset or by using the key in the driver's door lock, depending on system configuration.

NOTE: The “only disarm with key if locked with key” configuration prevents the alarm from being disarmed by unlocking the vehicle with the handset if the vehicle has been locked by the key. In this situation the Emergency Key Access (EKA) code must be entered to disarm the alarm.

In order for the alarm to trigger, the following conditions must be met: l Perimetric alarm armed. l Bonnet or door opened.

Once triggered, the alarm will remain triggered for 30 seconds before resetting.

Volumetric alarm The volumetric alarm is used by the BCU to detect movement within the vehicle. This allows the alarm to be triggered if a window is smashed in an attempt to gain access to the vehicle.

There are two volumetric alarm configurations: l Volumetric alarm not active. l Volumetric alarm active.

Two sensors, which transmit and receive ultrasonic signals, detect movement within the vehicle. Theses sensors detect any change in air movement within the vehicle and then supply the BCU a signal to activate the alarm. Fifteen seconds after the vehicle is locked with the handset or the key the volumetric alarm is armed. This delay is incorporated into the BCU software to prevent accidental or nuisance triggering of the alarm.

In order to arm the volumetric alarm, the following conditions must be met: l Driver's door closed. l Key not inserted in ignition. l Fuel cut-off switch not tripped.

To prevent the alarm from triggering when entering the vehicle, the alarm system must be disarmed with the key or the handset.

There are two volumetric alarm disarming configurations: l Always disarm with key. l Only disarm with key if locked with key.

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