1995 LAND ROVER DISCOVERY Workshop Manual

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DESCRIPTION AND OPERATION ALARM COMPONENT LOCATIONS (96 MODELS)
COMPONENT LOCATION
1. Electronic control unit (ECU) and relays Under dash (passenger side).................
2. Anti-theft alarm indicator light Instrument panel..................................
3. Engine immobilisation warning light (EIWL) * Instrument panel..........
4. Passive coil Over starter switch barrel.............................................................
5. Bonnet switch RH engine compartment..........................................................
6. Door switches
7. Ultrasonic sensor Interior light switch panel....................................................
8. Lock barrel, sill buttons
9. Handset and key
10. Battery backed-up sounder or horn * RH engine compartment......................
11. Immobilisation unit (spider) * Above heater...................................
12. Aerial Part of fascia harness.......................................................................
* where applicable

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DESCRIPTION AND OPERATION ANTI-THEFT ALARM DESCRIPTION (96 MODELS)
NOTE: The alarm system provides security
protection under wide ranging
circumstances and is fully programmable
to meet market requirements; consequently some
of the features listed will vary dependent on
vehicle model or territory.
The handset is intended to be the primary source of
control for the alarm system. The key should only be
used in the event of handset failure or if perimetric
arming only is required.
Immobilisation
After a time period the vehicle is automatically
immobilised regardless of whether or not the alarm is
armed.
Mobilisation
The handset provides the normal means of
mobilisation. In the event of handset failure, the key
may be used to enter the emergency key access
code.
Perimetric arming
Provides protection whilst the vehicle is still occupied.
Volumetric arming
If movement within the vehicle is detected the alarm
will be triggered.
NOTE: Perimetric arming always
accompanies volumetric arming.
Built-in test
The alarm system has a built-in test procedure, but if
possible any fault finding should normally be
undertaken using TestBook.
Emergency key access (EKA)
In the event of handset failure the alarm can be
disarmed by entry of the EKA code which is unique to
each vehicle.CONTROL SYSTEM
Electronic control unit (ECU) and relays
The ECU is the alarm system 'brain' and controls all
alarm functions. It responds to inputs received, by
supplying suitable outputs to indicate the status of the
alarm system or activating the relevant warning
devices.
Handset
The handset is the primary source of control for the
alarm system i.e. it locks and unlocks the vehicle,
arms and disarms the alarm.
Door key
The vehicle may be locked using the key (perimetric
arming only).
NOTE: The vehicle MUST be unlocked
using the handset. The key may be used to
unlock the vehicle if the handset fails to
operate, see operation, Emergency key access.
Passive coil
The passive coil is located around the starter switch
and triggers the handset (usually located on the
keyring) if it is within close proximity.
Aerial
The aerial is a floating connection which supplies the
alarm ECU with the signal received from the handset.
Immobilisation unit (spider)
Dependent on model or territory, the system may be
fitted with an immobilisation unit which is discreetly
located and provides an interface between the ECU
and immobilised areas of the vehicle.

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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.

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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.

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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.

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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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FAULT DIAGNOSIS GENERAL INFORMATION
The electrical fault diagnostic tool on Discovery
vehicles is Testbook. Detailed information of electrical
systems, component locations and circuit diagrams
are covered in the Discovery Electrical
Troubleshooting Manual.
See INTRODUCTION,
Information, Fault Diagnostic Equipment
This section covers checks of the charging and
ignition system.
GENERATOR TESTING
Service repair no - 86.10.01
Charging system check
1.Check battery is in good condition, with an open
circuit voltage of at least 12.6 V. Recharge or
substitute battery to carry out test.
2.Check drive belt condition.
See SECTION 10,
Maintenance, Under Bonnet [Hood]
Maintenance
3.Check battery connections are clean and tight.
4.Check generator connections are clean and
tight.
5.Ensure there is no drain on battery from, for
example, interior, under bonnet [hood] or door
edge lamps.
Generator test
Following instructions refer to use of suitable test
equipment using a carbon pile rheostat.
6.Connect test equipment referring to
manufacturer's instructions.
7.Start engine and run at 3000 rev/min without
accessory load.
8.Rotate carbon pile load control to achieve
greatest output (amps) without allowing voltage
to fall below 12.0 V. A reading in amps, of
generator output, minus 10% to allow for EFI
and Ignition loss, should be obtained.
9.Run engine at 3000 rev/min, switch selector to
regulator test, read voltmeter. A reading of 13.6
to 14.4 V should be obtained.
10.Switch selector to diode/stator test, switch on
headlamps to load generator. Raise engine
speed to 3000 rev/min, read voltmeter, needle
must be within 'OK' range.TESTING IN POSITION
Charging circuit resistance test.
1.Connect a low range voltmeter between
generator terminal marked B+ and positive
terminal of battery.2.Switch on headlamps, start engine. Run engine
at approximately 3000 rev/min. Note voltmeter
reading.
3.Transfer voltmeter connections to frame of
generator and negative terminal of battery, and
again note voltmeter reading.
4.If reading exceeds 0.5 volt on positive side or
0.25 volt on negative side, there is a high
resistance in charging circuit which must be
traced and remedied.

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FAULT DIAGNOSIS LUCAS CONSTANT ENERGY IGNITION SYSTEM -
V8i
Preliminary checks
Inspect battery cables and connections to ensure they
are clean and tight. Check electrical condition of
battery.
Inspect all L.T. connections, ensure they are clean
and tight. Check H.T. leads are correctly positioned
and not shorting to ground against any engine
components. Wiring harness and individual cables
should be firmly fastened to prevent chaffing.
Pick-up air gap
Check air gap between pick-up limb and reluctor teeth
is 0.20 - 0.35 mm, using a non-ferrous gauge.
NOTE: Air gap is set initially at factory and
will only require adjusting if tampered with
or when pick-up module is replaced.
TEST 1:
H.T. Sparking
Remove coil/distributor H.T. lead from distributor
cover and hold approximately 6mm from engine block,
using suitable insulated pliers. Switch ignition 'On' and
operate starter.
Regular sparking indicates fault in H.T. distribution,
plugs, timing or fuelling, proceed to Test 6. If no spark
or weak spark occurs proceed to Test 2.TEST 2:
L.T. Voltage
Switch ignition 'On' - engine stationary.
(a) Connect voltmeter to points in circuit indicated
by V1 to V4 and make a note of voltage
readings.
(b) Compare voltages obtained with specified
values listed below:
Expected readings
V1 More than 12 volts.
V2 1 volt maximum below volts at V1.
V3 1 volt maximum below volts at V1.
V4 0 volt - 0.1 volt.
(c) If all readings are correct proceed to Test 3.
(d) Check incorrect reading(s) with chart to identify
area of possible faults, i.e. faults listed under
heading SUSPECT and rectify.
(e) If coil and amplifier is suspected, disconnect L.T.
lead at coil, repeat V3. If voltage is still incorrect,
fit new coil. If voltage is now correct, check L.T.
lead, if satisfactory fit new amplifier.
(f) If engine will not start proceed to Test 3.