L322 Range Rover System Description and Operation
SECURITY
86-5-4
DESCRIPTION AND OPERATION
Description
General
The security system is split into three elements: the locking system, the alarm system and the immobilisation system.
The locking and alarm systems are controlled by the Body Control Unit (BCU). The immobilisation system is controlled
by a dedicated ECU. The arming and disarming of the alarm system is linked to the activation of the locking system.
The immobilisation system operation is independent of both the locking and the alarm systems.
Locking and Alarm Systems
All vehicles incorporate a remote handset Central Door Locking (CDL) system and an alarm system with perimetric
and volumetric protection functions. Specific features and modes of operation depend on the car/key memory settings
in the BCU.
The CDL system controls the locking and unlocking of the side doors and fuel filler flap, and the opening of the tail
doors. System features include automatic locking at a set vehicle speed and Single Point Entry (SPE).
The alarm system monitors for unauthorised entry, opening of doors and bonnet, vehicle movement and interference
with the electrical system, and sounds an alarm if an event is detected. The alarm system can be configured to
automatically arm and disarm with operation of the locking system. The locking and alarm systems incorporate:
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Actuators and switches in the door latches
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A bonnet switch
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A fuel filler flap actuator
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A CDL switch
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Upper tail door internal release switch
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Upper tail door external release switch
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Lower tail door release switch
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A lower tail door release relay
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Remote handsets
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A Radio Frequency (RF) receiver (market dependant)
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An infrared receiver (market dependant)
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An alarm Light Emitting Diode (LED)
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A Battery Backed Up Sounder (BBUS)
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A volumetric sensor
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A tilt sensor.
Door Latches
The side door latches are sealed units that incorporate separate actuators for locking and superlocking the doors, and
a Hall effect sensor to provide a door status signal for the BCU. The driver's door latch incorporates two additional
Hall effect sensors to provide signals of lock and unlock selections made with the ignition key in the door lock. Turning
the top of the ignition key rearwards sends a lock signal and turning the top of the ignition key forwards sends an
unlock signal. The driver and front passenger door latches communicate with the BCU via their respective door
modules and the P bus. The rear door latches are connected direct to the BCU.
The upper tail door latch incorporates a release actuator to open the upper tail door and a microswitch to provide an
upper tail door status signal. A black manual release wire is attached to the upper tail door latch to allow the latch to
be released in the event of actuator failure or loss of power. The end of the manual release wire is stowed in the inside
trim at the bottom edge of the upper tail door and is concealed by the trailing edge of the parcel shelf when the upper
tail door is closed.
Each lower tail door latch is connected to a release actuator mounted inside the tail door. A lever at the top of each
latch housing allows the latches to be released in the event of actuator failure or loss of power. The levers are only
accessible when the upper tail door is open.