Land Rover Discovery: Anti-theft - Active
COMPONENT LOCATION
![Anti-theft - Active / Description and Operation](images/books/227/index310(1).jpg)
- Central Junction Box (CJB)
- Instrument Cluster (IC)
- Immobilizer Antenna Unit (IAU)
- Smart key
- Radio Frequency (RF) receiver
- Battery Back-Up Sounder (BBUS)
- Hood switch
- Tailgate latch mechanism
- Keyless Vehicle Module (KVM)
- Volumetric sensor
- Driver Door Module (DDM) (passenger side fitted with a Passenger Door
Module
(PDM))
- Driver door latch mechanism (passenger door latch mechanism is the same)
- Rear Door Module (RDM) (2 off)
- Rear right door latch mechanism (rear left door latch mechanism is the
same)
OVERVIEW
The active anti-theft system monitors the hinged panels for unauthorized
opening. In some markets the anti-theft system also incorporates
monitoring of the vehicle interior and vehicle tilt sensing.
The active anti-theft alarm system is controlled by the following body
system control modules:
- Central Junction Box (CJB).
- Driver Door Module (DDM).
- Passenger Door Module (PDM).
- Instrument Cluster (IC).
The CJB is the main controller in the system. The CJB controls the following
security functions, in addition to other vehicle functions:
- Locking, double locking and unlocking.
- Monitoring of hinged panel micro switches and panel ajar states.
- Volumetric sensor.
- Battery Back Up Sounder (BBUS) or vehicle horns.
- Passive arming and disarming.
- Panic alarm function.
- Smart key transponder reading.
- Interior lighting.
Two levels of vehicle anti-theft alarm are available; perimeter mode
monitors all opening panels and volumetric mode (if fitted) monitors the
vehicle interior for intrusion and it also incorporates a tilt sensor to monitor
if the vehicle is being moved.
NOTE:
Volumetric mode and tilt sensing are not available in certain markets.
The smart key provides the following functionality:
- Unlock (central unlock or single point entry).
- Lock and double lock.
- Tailgate release.
- Approach lighting.
- Panic alarm.
The lock and unlock switches also control a 'lazy' lock and unlock feature
which will automatically close or open the windows with an extended press
of the applicable switch. This feature is only available in certain markets and
is controlled in conjunction with the door modules.
WARNING:
Never double lock the vehicle with any person or animal inside.
NOTE:
Double locking is only available in certain markets.
The smart key contains an emergency access key. This can be used in the
event of failure of the smart key or the vehicle battery to unlock the vehicle.
The driver door handle contains a concealed mechanical key barrel which
can be used with the emergency key to access the vehicle. This will not
disable the perimeter or interior alarm systems which will be activated when
the door is opened. To cancel the alarm, the smart key must be held next to
the Immobilizer Antenna Unit (IAU) and the stop/start switch must be
pressed.
For additional information, refer to: Handles, Locks, Latches and Entry
Systems (501-14 Handles, Locks, Latches and Entry Systems, Description
and Operation).
READ NEXT:
Description
The door modules provide the interface between the door latch motors, the
door and latch switches and the Central Junction Box (CJB). The door
modules provide door micro switch status info
Operation
The Central Junction Box (CJB) automatically arms and disarms the active
anti-theft system when it operates the Central Locking System (CLS).
On vehicles without a volumetric sensor, only t
PRINCIPLES OF OPERATION
For a detailed description of the Anti-Theft system, refer to the relevant
Description and Operation section in the workshop manual. REFER to: Anti-
Theft - Active (419-01A Ant
SEE MORE:
PART(S)
REMOVAL
WARNINGS:
Place the vehicle in a well ventilated, quarantined area and
arrange
' No Smoking/Petrol Fumes' signs about the vehicle.
Avoid flames, sparks or lighted substances.
Be prepared to collect escaping fuel.
It is imperative that new high pressure fuel pipes are always
PRINCIPLES OF OPERATION
For a detailed description of the Anti-Theft system, refer to the relevant
Description and Operation section in the workshop manual. REFER to: Anti-
Theft - Active (419-01A Anti-Theft - Active, Description and Operation).
INSPECTION AND VERIFICATION
CAUTION:
Diagnosis by subs