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Land Rover Discovery. Manual - part 203

ELECTRICAL

DESCRIPTION AND OPERATION

DETECTION COMPONENTS

Switches

Perimetric protection for the vehicle is provided by
ECU inputs connected to the following:

Key switches (including starter)
Sill buttons
Bonnet switch
Door switches

Ultrasonic sensor

The ultrasonic sensor is located on the interior light
switch panel and triggers the alarm if movement is
detected.

WARNING INDICATORS

Battery backed-up sounder

The battery backed-up sounder is located in the
engine compartment and provides an audible warning
whenever the alarm is triggered.

NOTE: Disconnecting the vehicle battery
will result in the alarm sounding if the
correct procedure has not been followed.

See Repair, Battery.

Engine immobilisation warning light (EIWL)

The engine immobilisation warning light is located in
the instrument pack and provides a visual indication
that the engine is immobilised.

Anti-theft alarm indicator light

The anti-theft alarm indicator light is located in the
instrument pack and provides a visual indication of the
alarm status.

Inertia switch and central door locking

As a safety feature, the alarm system is designed to
recognise the inertia switch and via the ECU, unlock
the doors in the event of a collision.

NOTE: This feature only applies when the
starter switch is in the on position.

ANTI-THEFT ALARM OPERATION (96 MODELS)

Full arming and immobilisation

Locking the vehicle using the handset immobilises the
engine and initializes both volumetric and perimetric
protection, providing:

1. After a lock signal has been received, a period of

15 seconds has elapsed during which no
movement is detected inside the vehicle;

2. No door or bonnet is open.

NOTE: If either of the above conditions are
not satisfied, the alarm will only be
partially armed. This is a mislock condition

which will be made apparent by a delay of 10
seconds before the anti-theft alarm indicator
begins to flash.

Disarming the alarm

NOTE: ALWAYS disarm the alarm using
the handset.

Unlocking with the key will not disarm the alarm or
mobilise the vehicle. If the handset fails to unlock the
vehicle

See Repair, Handset.

Partial arming and immobilisation

The alarm will be partially armed and the engine
immobilised if the vehicle is locked with the handset or
key, if:

1. After a lock signal has been received, a period of

15 seconds has elapsed during which movement
is detected inside the vehicle;

2. A door or bonnet is open.

NOTE: This is a mislock condition which
will be made apparent by a delay of 10
seconds before the anti-theft alarm

indicator begins to flash. Subsequent closure of
the offending aperture will cause the alarm to
attempt full arming as previously described.

Immobilisation

The vehicle will be automatically immobilised
whenever any of the following conditions occur:

1. The vehicle is locked using the handset.
2. The vehicle is locked using the key.
3. Thirty seconds after the starter switch has been

turned off AND the driver’s door opened.

4. Five minutes after the starter switch is turned off

or the alarm disarmed.

ELECTRICAL

DESCRIPTION AND OPERATION

Mobilisation

The vehicle can be mobilised using any one of the
following processes:

1. Placing the handset in close proximity to the

starter switch with the starter switch turned on
(normally achieved by placing the key in the
starter switch, providing the key and handset are
attached).

NOTE: Under normal circumstances the
remobilisation of the vehicle will not be
apparent.

2. Pressing unlock button on handset.
3. Pressing lock button on handset with starter

switch turned on.

4. Entry of EKA code using the key.

NOTE: Any attempt to start the vehicle
using the key (detached from the handset)
will be unsuccessful. Use one of the above

methods.

See Warning indicators.

Volumetric protection

When the vehicle is locked using the handset both
perimetric and volumetric protection are activated
providing there is no mislock condition.

Perimetric protection

The vehicle is always perimetrically protected when
the alarm is armed using the handset. Perimetric
protection only, can be achieved if the vehicle is
locked using the key.

NOTE: The handset should ALWAYS be
used for unlocking the vehicle. If the
handset fails to unlock the vehicle

See

Repair, Handset.

Battery backed-up sounder (BBUS)

The sounder provides audible indication of alarm
status including:

Anti-theft warnings;
Confirmation of access to built-in test.

NOTE: Disconnecting the vehicle battery
will result in the alarm sounding if the
correct procedure has not been followed.

See Repair, Battery.

Alarm horn

The horn provides audible indication (as BBUS) of
alarm status.

NOTE: Disconnecting the vehicle battery
will have no effect on the horn.

Engine immobilisation warning light (EIWL)

NOTE: Under normal circumstances the
light will not illuminate.

The light will only illuminate (after 2 seconds) if the
handset is detached from the key (or the handset
fails) and an attempt is made to start the vehicle.

Anti-theft alarm indicator light

The light flashes to indicate the alarm status.

If the alarm system is fully armed, the light will flash
rapidly for 10 seconds and then settle to the slow
(anti-theft deterrent) flash.

If the alarm system is perimetrically armed, the light
will intermittently flash rapidly for 10 seconds and then
settle to the slow (anti-theft deterrent) flash.

If the alarm system is partially armed, the light will
NOT emit the slow flash until 10 seconds after arming
(to allow the cause to be investigated).

If the vehicle has been left unlocked, providing the
driver’s door is closed, the light will flash slowly
indicating immobilisation. If the driver’s door is open,
the light will remain illuminated.

Emergency key access (EKA)

The emergency key access code should be entered in
accordance with the instructions in the Owner’s
Handbook.

ELECTRICAL

DESCRIPTION AND OPERATION

Radio frequency system

The RF system uses frequencies according to market
and both ECU and handset are colour coded:

Territory

ECU/Handset

...............................

Frequency

..................

Europe

Blue/Blue

..................................

433.92 MHz

.........................

NAS

Green/Green

.......................................

315.00 MHz

....................

Japan

Green/Green

....................................

315.00 MHz

....................

Gulf

Green/Green

.......................................

315.00 MHz

....................

Rest of World

Green/Brown

........................

315.00 MHz

...................

NOTE: In service NAS, Japan and Gulf will
have the handset changed to brown.

Passive coil

The passive coil excites a receiving coil in the handset
causing it to automatically transmit a remobilisation
signal to the ECU.

Inertia switch and central door locking

Actuation of the inertia switch will cause the doors to
be unlocked. A time-out period (programmable
between 0-5 minutes) will ensue, during which all CDL
and alarm activity is disabled.

NOTE: This feature only applies when the
starter switch is in the on position.

Handset

Under normal circumstances pressing the respective
buttons on the handset once, will unlock or lock the
vehicle. If operating the handset does not achieve the
desired effect

See Repair, Handset.

Functional detail

For full functional details and circuit diagrams

See

Electrical Trouble Shooting Manual..

Vehicle traceability

All Land Rover vehicles are fitted with a multitude of
discreet security features to prevent theft or assist
recovery in the event of a vehicle being stolen. All
vehicles are traceable, since it is impossible to
remove all security identification.

ELECTRICAL

DESCRIPTION AND OPERATION

ANTI-THEFT ALARM BUILT-IN TEST (96 MODELS)

NOTE: The handset should be detached
from the key to allow perimetric testing of
the alarm system. The system will

automatically switch to volumetric testing if the
handset is in close proximity to the starter switch.

The built-in test procedure can be accessed providing
the following conditions exist:

Alarm disarmed.
Ignition off.
Doors unlocked.
Bonnet[hood] closed.

The test mode can be entered by completing the
following instructions within 5 seconds:

1. Open bonnet.
2. Turn starter switch on.
3. Open driver’s door (far enough to activate

switch).

4. Turn starter switch off.
5. Turn starter switch on.

If the test mode has been correctly accessed, the
sounder/horn will operate briefly and the anti-theft
alarm indicator and hazard warning lights will flash.

Perimetric tests

The anti-theft alarm indicator light and the hazard
warning lights will flash when:

1. Door switches are activated;
2. The bonnet is opened;
3. Sill switches are activated;
4. Key switches are activated.

NOTE: Operation of key switches can be
verified by turning the key in the relevent
direction so as not to simultaneously

activate the sill switch. If the key switch changes
state, the change should be detected but the sill
switch will not be activated.

Volumetric tests

Press the unlock button or move the handset close to
the starter switch to disable perimetric testing and
enable volumetric testing. If movement is detected
within the vehicle by the ultrasonic sensor it will be
indicated by flashing the anti-theft alarm indicator and
hazard warning lights.

NOTE: Exit anti-theft alarm built-in test by
turning starter switch to the off position.

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