engine oil LAND ROVER DEFENDER 1996 Repair Manual

86ELECTRICAL
2
DESCRIPTION AND OPERATION VEHICLE IMMOBILISATION AND ALARM SYSTEM
A sophisticated engine immobilisation and anti-theft
alarm system is offered on the Land Rover Defender
300 Tdi vehicle range, which incorporates the
following features:
Perimeter protection
This part of the alarm system protects side doors,
bonnet and rear door against unauthorised entry -
alarm sounding if any one of these apertures is
opened without alarm first being disarmed.
Interior protection
Also known as volumetric protection, this part of the
system protects space inside the vehicle. Once
armed, the alarm will sound if a door is opened, or if
movement is detected inside the vehicle.
Engine immobilisation
The engine is immobilised electronically whenever the
alarm system is armed. Even if the alarm has not
been armed, engine immobilisation will occur
automatically thirty seconds after the driver's door is
opened, or five minutes after the starter switch is
turned to position '0'.
ALARM SYSTEM COMPONENTS
Electronic control unit (ECU)
The ECU is the alarm system brain and controls all
vehicle immobilisation and alarm functions. It
responds to the inputs received, by supplying suitable
outputs to indicate status of the alarm system or
activating relevant warning devices. unit is located
under fascia behind instrument binnacle.
Handset and key
The handset is the primary source of control for the
alarm system i.e. it arms and disarms the alarm
components. The key can be used to override engine
immoblisation if the handset is lost or fails to operate,
seeEngine immobilisation override.The handset battery should last for approximately
three years dependent upon use. The following
symptoms will be noticed when the battery requires
replacement:
1.The handset will only work every other operation
while disarming.
2.The direction indicator lamps will not flash when
the alarm is disarmed.
For battery replacement procedure, seeHandset
Battery.
Passive coil
The passive coil is fitted on the starter switch and
activates a receiving coil in the handset, causing it to
automatically transmit a remobilisation signal to the
ECU.
Aerial
The aerial is integral within the alarm system harness
and supplies the ECU with the signal received from
handset.
Immobilisation spider
The immobilisation spider provides an interface
between ECU and immobilised areas of the vehicle.
This is installed in a sealed (safe) box inside the
vehicle battery box.
Digital diesel shut-off valve - 97 MY
When fitted, the digital diesel shut-off valve
immobilises the fuel injection pump by preventing
power reaching the fuel shut-off solenoid,
See
Immobilisation and alarm system circuit diagram -
with DDS
.

86ELECTRICAL
4
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
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
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.

ELECTRICAL
11
REPAIR REV: 05/99 Refit
12.Fit new fuse.
13.Position instrument panel to fascia cowl area
and reconnect immobiliser warning light leads,
gearbox oil temperature lead, heated rear screen
leads, alarm LED plug lead, main harness
multi-plugs and speedometer cable,
14.Secure instrument panel to fascia cowl with 4
screws
See INSTRUMENTS, Repair,
Instrument panel.
15.Fit steering wheelSee STEERING, Repair,
Steering wheel.
16.Reconnect battery negative lead.
17.Fit battery access cover.
18.Fit LH front seat cushion.GENERATOR
Service repair no - 86.10.02
Remove
1.Disconnect battery.
2.Remove drive belt
See Auxiliary drive belt.
3.Unscrew 3 fixings, remove heat shield from rear
of generator, and disconnect electrical leads
from generator.
4.Remove generator bottom fixing bolt.
5.Remove long through bolt from top fixing and lift
generator from engine.
Refit
6.Fit generator to engine mounting bracket and
secure with top and bottom fixing bolts.
7.Connect electrical leads.
8.Fit heat shield.
9.Fit drive belt
See Auxiliary drive belt; Refit.
10.Reconnect battery.