1996 LAND ROVER DEFENDER ECU

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.

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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.

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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

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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

86ELECTRICAL
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REPAIR BATTERY
Service repair no - 86.15.01
NOTE: If the vehicle is fitted with a battery
backed-up alarm sounder, disconnecting
the vehicle battery will cause the alarm to
sound unless the following procedure is followed:
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery WITHIN 15 SECONDS.
If alarm is accidentally activated, ensure sounder is
connected and silence by turning the starter switch to
position 'II'.Remove
WARNING: During battery removal or
before carrying out any repairs or
maintenance to electrical components
always disconnect negative lead first. If positive
lead is disconnected with negative lead in place,
accidental contact of a wrench to any grounded
metal part could cause a severe spark, possibly
resulting in personal injury. Upon installation of
battery always connect positive lead first.
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Disconnect both battery leads, negative first.
4.Slacken securing nuts and move battery clamp,
with 'J' bolts aside.
5.Remove battery.
NOTE: Coat battery clamps and terminals
with petroleum jelly before refitting.
Refit
6.Position battery and secure with clamp. Ensure
'J' bolts are hooked correctly under retaining
brackets on base of battery box.
7.Reconnect battery leads, positive lead first.
8.Fit battery access cover.
9.Fit seat cushion.

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REPAIR ELECTRONIC CONTROL UNIT (ECU)
Service repair no - 86.55.85
Remove
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery negative lead.
NOTE: Operation 6 needs to be carried out
within 15 seconds to avoid activating
battery backed-up alarm sounder, if fitted.
7.Remove steering wheel
See STEERING,
Repair, Steering wheel.
8.Remove 4 screws securing instrument panel to
fascia cowl
See INSTRUMENTS, Repair,
Instrument panel.
9.Pull instrument panel away from fascia cowl and
disconnect speedometer cable, multi-plugs,
alarm LED plug lead, heated rear screen lead,
gearbox oil temperature lead and immobiliser
warning light leads.
10.Remove instrument panel.
11.Remove 2 screws securing ECU to fascia cowl
(LH drive shown). On RH drive vehicles ECU is
positioned lower down, on vertical face of fascia
panel.
12.Release ECU from fascia cowl and disconnect
both multi-plugs.
13.Remove ECU.
NOTE: A new ECU must be initialised
using TestBook.
Refit
14.Position ECU at fascia cowl and reconnect both
multi-plugs.
15.Locate ECU on mounting face of fascia cowl and
secure with 2 screws.
16.Position instrument panel to fascia cowl and
reconnect immobiliser warning light leads,
gearbox oil temperature lead, heated rear screen
lead, alarm LED plug lead, multi-plugs and
speedometer cable.
17.Secure instrument panel to fascia cowl with 4
screws
See INSTRUMENTS, Repair,
Instrument panel.
18.Fit steering wheelSee STEERING, Repair,
Steering wheel.
19.Reconnect battery negative lead.
20.Fit battery access cover.
21.Fit LH seat cushion.

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REPAIR PASSIVE COIL
Service repair no - 86.77.35
Remove
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery negative lead.
NOTE: Operation 6 needs to be carried out
within 15 seconds to avoid activating
battery backed-up alarm sounder, if fitted.
7.Remove steering wheel
See STEERING,
Repair, Steering wheel.
8.Remove 4 screws securing instrument panel to
fascia cowl
See INSTRUMENTS, Repair,
Instrument panel.
9.Pull instrument panel away from fascia and
disconnect speedometer cable, multi-plugs,
alarm LED plug lead, heated rear screen lead,
gearbox oil temperature lead and immobiliser
warning light leads.
10.Remove instrument panel.
11.Remove 7 screws securing upper and lower
halves of nacelle to steering column mounting
bracket
See STEERING, Repair, Steering
column nacelle.
12.Release multi-switch gaiters from both sides of
nacelle.
13.Remove nacelle upper and lower halves from
steering column; collect blanking grommet from
RH side.
14.Disconnect multi-plug and remove passive coil
from starter switch.
Refit
15.Feed passive coil plug lead into fascia cowl area
and reconnect multi-plug .
16.Fit coil on starter switch.
17.Position nacelle upper and lower halves to
steering column mounting bracket and secure
with 7 screws. Do not fully tighten screws at this
stage
See STEERING, Repair, Steering
column nacelle.
18.Check that passive coil is still fitted correctly on
starter switch.
19.Check fit of nacelle at starter switch and steering
column and fully tighten fixing screws.
20.Fit multi-switch gaiters to both sides of nacelle
and check that blanking grommet is located.
21.Position instrument panel to fascia cowl area
and reconnect immobiliser warning light leads,
gearbox oil temperature lead, heated rear screen
lead, alarm LED plug lead, main harness multi-
plugs and speedometer.
22.Secure instrument panel to fascia cowl with 4
screws
See INSTRUMENTS, Repair,
Instrument panel.
23.Fit steering wheelSee STEERING, Repair,
Steering wheel.
24.Reconnect battery negative lead.
25.Fit battery access cover.
26.Fit LH seat cushion.
27.Test immobilisation and alarm system.