ECU LAND ROVER DISCOVERY 1995 Workshop Manual

86ELECTRICAL
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DESCRIPTION AND OPERATION BUILT IN TEST PROCEDURE
The built in test procedure is accessed as follows:
1.Starting conditions: ignition off, doors unlocked,
bonnet [hood] switch depressed.
2.Carry out instructions 3 to 7 within 8 seconds.
3.Release bonnet [hood] switch.
4.Switch ignition ON.
5.Lock doors.
6.Switch ignition OFF.
7.Switch ignition ON.
If alarm is correctly accessed, horn will sound and
LED will flash. The following checks can be made:
8.Open and close any door or tailgate - LED will
light.
9.Depress bonnet [hood] switch - hazards will
flash.
10.Check engine cranking is disabled. Do not turn
off ignition.
11.Check ultrasonic by operating handset, LED will
emit one 5 second flash, and will flash if interior
is disturbed.
NOTE: If ECU is new born mode any
handset of the right frequency will work. If
not an initialised handset is required see
Handset Initialisation.
12.Turn OFF ignition or press handset to end test
procedure. Horn will sound as before to indicate
end of test mode.

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5
DESCRIPTION AND OPERATION ANTI THEFT ALARM SYSTEM
The main function of the system is to offer easy to use
remote locking and unlocking of the vehicle without
having to actively select the alarm function.
ALARM COMPONENTS
COMPONENT LOCATION
1. Electronic control unit (ECU) and relays Passenger footwell.................
2. Bonnet switch RH engine bay..........................................................
3. Door switches
4. Alarm sounder RH engine bay.........................................................
5. Light emitting diode (LED) Dash panel.......................................
6. Ultrasonic unit Roof map pocket.........................................................
7. Lock barrel, sill buttons
8. Handset transmitter
9. Aerial 'A' post, passenger side........................................................................

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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 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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ADJUSTMENT IGNITION TIMING
Service repair no - 86.35.15
Adjust
1.It is essential that following procedures are
adhered to. Inaccurate timing can lead to serious
engine damage and additionally create failure to
comply with emission regulations. If timing is
being checked in vehicle, air conditioning
compressor must be disengaged.
2.On initial engine build, or if distributor has been
disturbed for any reason, ignition timing must be
set statically to 6°B.T.D.C.
NOTE: This approximate setting is made
only to ensure that engine may be started.
CAUTION: On no account must engine be
started before this operation is carried out.Equipment required :-
Calibrated Tachometer
Stroboscopic lamp
3.Couple stroboscopic timing lamp and tachometer
to engine following manufacturer's instructions.
4.Disconnect vacuum hose from distributor.
5.Start engine. With no load, and without
exceeding 3,000 rev/min run engine until normal
operating temperature is reached. (Thermostat
open). Check that engine idles within tolerance
specified in data section.
6.Idle speed for timing purposes must not exceed
800 rev/min.
7.Run engine at idle speed and check timing using
stroboscope light on timing marker and pointer.
WARNING: Keep hands and equipment
away from belt.
8.If timing is not as specified, switch off engine.
Loosen distributor clamp bolt and turn distributor
to advance or retard ignition as necessary.
Tighten clamp bolt, start engine and recheck
timing.
WARNING: Personal injury may result if an
attempt is made to adjust distributor whilst
engine is running.
9.Upon completion, switch off engine and retighten
distributor clamping bolt securely. Recheck
timing, to ensure retightening has not disturbed
distributor position.
10.Refit vacuum hose.
11.Disconnect stroboscopic timing lamp and
tachometer from engine.

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REPAIR BATTERY
Service repair no - 86.15.01
NOTE: Some vehicles are fitted with a
battery backed-up sounder. Disconnecting
the vehicle battery will cause the alarm to
sound unless the following procedure is followed:
1.Turn starter switch 'ON' then 'OFF'.
2.Disconnect battery WITHIN 15 SECONDS (see
WARNING).
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 battery negative lead first. If
positive lead is disconnected with negative lead in
place, accidental contact of wrench to any
grounded metal part could cause a severe spark,
possibly resulting in personal injury. Upon
installation of battery connect positive lead first.
3.Disconnect both battery leads, negative first.
4.Release four nuts securing battery bracket in
position.
5.Remove bracket.
6.Remove battery.
Refit
7.Reverse removal procedure.
NOTE: Coat battery clamps and terminals
with petroleum jelly before refitting.DISTRIBUTOR-LUCAS 35 DLM8 - V8i
Service parts
1. Cap
2. HT brush and spring
3. Rotor arm
4. Insulation cover
5. Pick-up module and base plate assembly
6. Vacuum unit
7. Amplifier module
8. 'O'-ring oil seal
9. Gasket

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REPAIR ELECTRONIC IGNITION - V8i
A Lucas 35DLM8 distributor is employed. This has a
conventional vacuum advance unit and centrifugal
automatic advance mechanism.
A pick-up module, in conjunction with a rotating timing
reluctor inside distributor body, generates timing
signals. These are applied to an electronic ignition
amplifier module mounted on side of distributor body.
NOTE: Pick-up air gap is factory set. Do
not adjust gap unless pick-up is being
changed or base plate has been moved.
Use a non-ferrous feeler gauge to set air gap.
IGNITION COIL
Service repair no - 86.35.32
Remove
1.Disconnect battery negative lead.
2.Noting their fitted positions, disconnect electrical
leads from ignition coil.
3.Remove two bolts securing ignition coil clamp,
recover suppressor.
4.Remove coil.
Refit
5.Reverse removal procedure.DISTRIBUTOR - V8i
Service repair no - 86.35.20
Remove
1.Disconnect battery negative lead.
2.Disconnect vacuum hose.
3.Remove distributor cap.
4.Disconnect low tension lead from coil.
5.Mark distributor body and centre line of rotor
arm.
6.Add alignment marks to distributor and front
cover.
NOTE: Marking distributor enables
refitting in exact original position, but if
engine is turned while distributor is
removed, complete ignition timing procedure
must be followed.
7.Release distributor clamp and remove
distributor.

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REPAIR Refit
NOTE: If a new distributor is being fitted,
mark body in same relative position as
distributor removed.
8.Leads for distributor cap should be connected as
illustrated.
Figures 1 to 8 inclusive indicate plug lead
numbers.
RH-Right hand side of engine, when viewed
from rear.
LH-Left hand side of engine, when viewed from
rear.
9.If engine has not been turned while distributor
has been removed, carry out instructions 10. to
17. Alternatively proceed to instruction 18.
10.Fit new 'O' ring seal to distributor housing.
11.Turn distributor drive until centre line of rotor arm
is 30Ê anti-clockwise from mark made on top
edge of distributor body.
12.Fit distributor in accordance with alignment
markings.
NOTE: It may be necessary to align oil
pump drive shaft to enable distributor
drive shaft to engage in slot.
13.Fit clamp and bolt. Secure distributor in exact
original position.
14.Connect vacuum hose to distributor and low
tension lead to coil.
15.Fit distributor cap.
16.Reconnect battery.
17.Using suitable electronic equipment, set ignition
timing.
See Adjustment, Ignition timing
18.If engine has been turned with distributor
removed, carry out instructions 19 to 30.
19.Set engine-No. 1 piston to static ignition timing
figure
See ENGINE TUNING DATA,
Information, Engine 3.9 V8i
20.Turn distributor drive until rotor arm is
approximately 30Ê anti-clockwise from number
one sparking plug lead position on cap.
21.Fit distributor to engine.
22.Check that centre line of rotor arm is now in line
with number one sparking plug lead on cap.
Reposition distributor if necessary.
23.If distributor does not seat correctly in front
cover, oil pump drive is not engaged. Engage by
lightly pressing down distributor while turning
engine.
24.Fit clamp and bolt, do not tighten.
25.Set ignition timing statically to 6Ê B.T.D.C.
26.Connect vacuum hose to distributor.
27.Fit low tension lead to coil.
28.Fit distributor cap.
29.Reconnect battery.
30.Using suitable electronic equipment set the
ignition timing.
See Adjustment, Ignition
timing