1996 LAND ROVER DEFENDER engine

ELECTRICAL
3
DESCRIPTION AND OPERATION Door and bonnet switches
Perimetric protection for the vehicle is provided by
ECU inputs connected to the starter switch, bonnet
switch and door switches.
Ultrasonic sensor
The ultrasonic sensor operates by emitting an air
pressure carrier wave which is subsequently received
by the sensor as it bounces back from objects inside
the vehicle. Once armed, the alarm will sound if wave
is disturbed by a door opening, or if movement is
detected inside the vehicle.
When the volumetric sensor is activated it monitors
movement within the vehicle for 15 seconds before
detecting and responding to intrusions. If the sensor
detects movement it delays arming until a quiet period
has lapsed; if continuous movement is detected, the
alarm will not arm volumetrically.
NOTE: Interior protection will not operate
until 15 seconds after alarm is set.
The ultrasonic sensor is positioned in a different
location, according to vehicle type, as follows:
·90/110 Station Wagon - RH cantrail trim
·90/110 Pick-up - On headlining, between interior
lamp and rear view mirror
·130 Crewcab - On headlining above RH door
Alarm sounder
Two types of alarm sounder can be fitted, one with a
battery back-up facility and or without battery back-up,
both providing an audible warning whenever the alarm
is triggered. The vehicle horn will also operate if the
alarm sounds.
The alarm sounder is fitted to LH inner front wing in
the engine compartment.
NOTE: Disconnecting the battery on
vehicles fitted with the battery backed-up
facility will result in the alarm sounding, if
correct procedure has not been followed.Engine immobilisation warning light
The engine immobilisation warning light is located on
the instrument panel, and provides a visual indication
that the engine is immobilised.
Anti-theft alarm indicator light
The anti-theft alarm indicator light is located on the
instrument panel, between the fuel and coolant
temperature indicators, and provides a visual
indication of the alarm/ immobiliser status.

86ELECTRICAL
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DESCRIPTION AND OPERATION REV: 05/99 ALARM SYSTEM COMPONENT LOCATION
COMPONENT LOCATION
1. Electronic control unit (ECU) Under dash, LH and RH drive
2. Anti-theft alarm indicator light Instrument panel
3. Engine immobilisation warning light Instrument panel
4. Immobilisation spider* Inside vehicle battery box
5. Passive coil Over starter switch barrel
6. Bonnet switch Engine compartment, LH and RH drive
7. Door switches
8. Ultrasonic sensor Varies according to vehicle type
9. Handset and key
10. Alarm sounder (without battery back-up) LH inner front wing
11. Alarm sounder (with battery back-up) LH inner front wing
* Replaced in some markets by a digital diesel shut-off valve (DDS), secured directly to fuel shut-off solenoid on
injection pump.

ELECTRICAL
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DESCRIPTION AND OPERATION REV: 05/99 ALARM SYSTEM OPERATION
Arming alarm
To arm the alarm, aim handset at vehicle and press
the RH button (Padlock symbol). Provided all doors
and or apertures are closed, the direction indicator
lamps will flash three times to confirm that the alarm is
armed. All security features previously described will
be active.
Once armed, the alarm will sound if a door or the
bonnet is opened, or if movement is detected inside
the vehicle.
Disarming alarm
Within range of the vehicle, briefly press the LH
(Plain) button on the handset; the direction indicator
lamps will flash once to indicate that the alarm has
been disarmed and the engine re-mobilised.
NOTE: In some territories, the interior
lamps will illuminate when the alarm is
disarmed.
If the direction indicators fail to flash when the
alarm is armed:
This indicates that a door or the bonnet is not fully
closed, in which case the alarm will be partially armed
and engine immobilised, but interior protection will not
be active.
Once the open door or bonnet is closed, the direction
indicators will flash three times and the alarm will fully
arm as described previously.
If the alarm sounds:
The vehicle horn and alarm sounder will operate
continuously for 30 seconds when the alarm is
triggered. The horn and alarm sounder can be
triggered up to three times.
To silence the alarm, press either handset button. If
the handset is inoperative, the alarm can only be
disarmed by entering the emergency key access
code, seeEngine immobilisation override.Anti-theft alarm indicator light
A RED indicator light on the instrument panel
indicates the status of the alarm system. When the
alarm is armed successfully, the light flashes rapidly.
After 10 seconds, the light adjusts to a slower
frequency and continues flashing as an anti-theft
deterrent.
If the light fails to illuminate during the rapid flash
phase, this indicates a 'mislock' (door or the bonnet
not fully closed or key in starter switch). If this occurs,
the indicator light will still flash at slower frequency as
an anti-theft deterrent.
The indicator light will illuminate continuously under
the following conditions:
1.Alarm system armed and immobilised with
ignition 'on' or driver's door open.
2.Engine immobilised with ignition 'on' or driver's
door open.
Interior protection
Interior protection is activated automatically when the
alarm system is armed; twin sensors inside the
vehicle monitor interior space and will activate the
alarm if an intrusion is detected.
However, if passengers or animals are to be left inside
the vehicle, or if a window or sunroof is to be left
open, the alarm must be armed with the interior
protection DISABLED as follows:
To disable interior protection:
1.Open the driver's door.
2.Use the handset to arm the alarm in normal way.
3.Close the driver's door (the direction indicator
lamps will flash three times and the anti-theft
indicator light commences flashing rapidly). The
alarm system is now armed with the interior
protection disabled.
NOTE: Interior protection will not operate
until 15 seconds after the alarm is set.

86ELECTRICAL
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DESCRIPTION AND OPERATION REV: 05/99 ENGINE IMMOBILISATION
Engine immobilisation is an important aspect of the
vehicle's security system, and occurs automatically
whenever the alarm system is armed.
The system also includes a feature known as 'passive
immobilisation', which is designed to safeguard the
vehicle from theft should the driver forget to arm the
alarm.
Passive immobilisation occurs automatically as
follows:
·Thirty seconds after the starter switch has been
turned off and the driver's door opened.
·Five minutes after the starter switch is turned off or
the alarm system is disarmed.
If the engine has immobilised passively,
re-mobilisation will occur when the starter switch is
turned to position 'II', provided the handset is on the
same ring as key and in close proximity to the switch.
ALWAYS keep the handset on the same ring as the
key.
NEVER attach both handsets to the same key ring.
Any attempt to start the engine while it is immobilised
will cause the engine immobilisation warning light to
flash.
Engine immobilisation override
If the handset is lost or fails to operate, the engine
immobilisation can be overridden by using the starter
key to enter the four digit emergency access code.
The procedure for entering the code is described after
the following note:
NOTE: If the handset is lost or inoperative,
it is impossible to disarm the alarm. As
soon as the door is opened, the alarm will
sound (continuously for up to three 30 second
periods), and continue while the code is being
entered.
1.With the driver's door closed, insert the key into
the starter switch.
2.Turn the switch to position 'II' the required
number of times to enter first digit of code (if first
digit is 4, turn key to position 'II' and then back to
'0' four times.
3.Open the driver's door (to enter first digit) and
then close the door again.
4.Turn the starter switch to position 'II' and back to
'0' the required number of times to enter
SECOND digit of code.
5.Open the driver's door (to enter second digit)
and then close the door again.
6.Turn the starter switch to position 'II' and back to
'0' the required number of times to enter THIRD
digit of code.
7.Open the driver's door (to enter third digit) and
then close door again.
8.Turn the starter switch to position 'II' and back to
'0' the required number of times to enter
FOURTH digit of code.
9.Finally, open and close the driver's door. If the
code has been entered correctly, the anti-theft
indicator light will extinguish, the engine can be
started and the alarm will disarm.
If an incorrect code has been entered:
If the code is entered incorrectly, the anti-theft
indicator light will continue to illuminate and the
engine will fail to start. Before entering the code again,
turn the starter switch to position 'II', hold in this
position for 5 seconds and then switch off.
After three failed attempts, the security system
invokes a delay period of thirty minutes during which
the system will not accept any further codes.

ELECTRICAL
9
DESCRIPTION AND OPERATION IMMOBILISATION AND ALARM SYSTEM CIRCUIT
DIAGRAM
1.Anti-theft alarm indicator light (LED)
2.Engine immobilisation warning light
3.Alarm system fuse - 15 amp
4.Alarm sounder relay
5.Under bonnet lighting fuse
6.Alarm sounder (without battery back-up)
7.Alarm system fuse - 5 amp (position 20)
8.Electronic control unit (ECU)
9.Bonnet switch
10.Alarm sounder protection fuse - 20 amp
(position 10)
11.Starter switch
12.Under bonnet ignition fuse
13.Driver's door switch
14.Vehicle horn switch
15.Vehicle horn
16.Passive coil
17.Starter switch relay
18.Front passenger door switch
19.Hazard warning light fuse - 15 amp (position 1)
20.Ultrasonic sensor
21.Interior lamp and horn fuse - 20 amp (position 3)
22.Alarm sounder (with battery back-up)
23.LH direction indicator lamps
24.RH direction indicator lamps
25.Interior lamp
26.Immobilisation spider
27.Rear side doors and rear door switches
28.Diagnostic connector
29.Diagnostic fuse - 7.5 amp
30.Starter solenoid
31.Fuel switch-off solenoid (injection pump)
32.Generator
33.AerialKey to cable colours
B-Black
G-Green
K-Pink
LG-Light Green
N-Brown
O-Orange
P-Purple
R-Red
S-Slate
U-Blue
W-White
Y-Yellow
The last letter of a colour code denotes the tracer
colour

ELECTRICAL
11
DESCRIPTION AND OPERATION IMMOBILISATION AND ALARM SYSTEM CIRCUIT
DIAGRAM - WITH DDS
1.Anti-theft alarm indicator light (LED)
2.Engine immobilisation warning light
3.Alarm system fuse - 15 amp
4.Alarm sounder relay
5.Under bonnet lighting fuse
6.Alarm sounder (without battery back-up)
7.Alarm system fuse - 5 amp (position 20)
8.Electronic control unit (ECU)
9.Bonnet switch
10.Alarm sounder protection fuse - 20 amp
(position 10)
11.Starter switch
12.Under bonnet ignition fuse
13.Driver's door switch
14.Vehicle horn switch
15.Vehicle horn
16.Passive coil
17.Starter switch relay
18.Front passenger door switch
19.Hazard warning light fuse - 15 amp (position 1)
20.Ultrasonic sensor
21.Interior lamp and horn fuse - 20 amp (position 3)
22.Alarm sounder (with battery back-up)
23.LH direction indicator lamps
24.RH direction indicator lamps
25.Interior lamp
26.Digital diesel shut-off valve (DDS)
27.Rear side doors and rear door switches
28.Diagnostic connector
29.Diagnostic fuse - 7.5 amp
30.Starter solenoid
31.Fuel shut-off solenoid (injection pump)
32.Generator
33.AerialKey to cable colours
B-Black
G-Green
K-Pink
LG-Light Green
N-Brown
O-Orange
P-Purple
R-Red
S-Slate
U-Blue
W-White
Y-Yellow
The last letter of a colour code denotes the tracer
colour

ELECTRICAL
1
FAULT DIAGNOSIS GENERAL INFORMATION
Detailed information of electrical systems, component
locations and circuit diagrams are covered in the
Defender Electrical Troubleshooting Manual.
This section covers checks of the charging 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 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 or exteriorlamps.
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 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.

ELECTRICAL
1
REPAIR ELECTRICAL PRECAUTIONS
The following guidelines are intended to ensure the
safety of the operator whilst preventing damage to
electrical and electronic components fitted to the
vehicle.
Polarity
Never reverse connect the vehicle battery and always
observe the correct polarity when connecting test
equipment.
High voltage circuits
WARNING: Before commencing work on
an ignition system, all high tension
terminals, adaptors and diagnostic
equipment for testing should be inspected to
ensure that they are adequately insulated and
shielded to prevent accidental personal contacts
and minimize the risk of shock. Wearers of
surgically implanted pacemaker devices should
not be in close proximity to ignition circuits or
diagnostic equipment.
Whenever disconnecting live high tension circuits
always use insulated pliers and never allow the open
end of a high tension lead to come into contact with
other components particularly electronic control units.
Exercise caution when measuring the voltage on the
coil terminals while the engine is running, since, high
voltage spikes can occur on these terminals.
Connectors and harness
Always ensure that these items are dry and oil free
before disconnecting and connecting test equipment.
Never force connectors apart either by using tools or
by pulling on the wiring harness. Always ensure
locking tabs are disengaged before removal and note
orientation to enable correct reconnection. Ensure that
any protective covers and substances are replaced if
disturbed. Having confirmed a component to be faulty
switch-off the ignition and disconnect the battery.
Remove the component and support the disconnected
harness. When replacing the component keep oily
hands away from electrical connection areas and
push connectors home until any locking tabs fully
engage.Battery disconnecting
Before disconnecting the battery, switch off all
electrical equipment.
Battery charging
Recharge the battery out of the vehicle and keep the
top well ventilated. While being charged or
discharged, and for approximately 15 minutes
afterwards, batteries emit hydrogen gas which is
flammable. Always ensure any battery charging area
is well ventilated and that every precaution is taken to
avoid naked flames and sparks.
GENERAL PRECAUTIONS
Switch-off ignition prior to making any connection or
disconnection in the system as electrical surge
caused by disconnecting 'live' connections can
damage electronic components.
Ensure hands and work surfaces are clean and free of
grease, swarf, etc. as grease collects dirt which can
cause tracking or high-resistance contacts.
When handling printed circuit boards, treat them as
you would a disc - hold by the edges only.
Prior to commencing a test, and periodically during a
test, touch a good earth, for instance, a cigar lighter
socket, to discharge body static as some electronic
components are vulnerable to static electricity.