reset LAND ROVER DISCOVERY 1995 Service Repair Manual

10MAINTENANCE
4
MAINTENANCE UNDER BONNET [HOOD] MAINTENANCE
CHECK COOLING/HEATER SYSTEMS
Check cooling/heater systems for leaks and hoses for
security and condition.
Cooling system hoses should be changed at first
signs of deterioration.
CHECK CONDITION OF ENGINE MOUNTING
RUBBERS
CHECK BRAKE SERVO HOSE FOR SECURITY
AND CONDITION
CHECK FUEL EVAPORATIVE LOSS CONTROL
SYSTEM FOR LEAKS - V8i CATALYST, Mpi
CHECK FUEL FILLER CAP SEAL FOR LEAKS - V8i
- CATALYST, Mpi
CHECK CONDITION OF HEATER PLUG WIRING
FOR FRAYING, CHAFING AND DETERIORATION -
Tdi
CHECK IGNITION WIRING
Check ignition wiring and high tension leads for
fraying, chafing and deterioration.
CLEAN DISTRIBUTOR CAP - V8i
The electronic ignition employs a Lucas 35DLM8
distributor.
Internal operating parts of distributor are pre-set at
factory and do not normally require resetting.
Adjustments should only be made if unit is known to
be faulty or damaged. Distributor maintenance
consists of following items.
1.Clean outer surfaces of distributor cap to remove
dirt, grease etc.
2.Unclip cap, check cap for cracks.
3.Wipe inside cap with lint free cloth.
4.Check rotor arm, cap and flash shield tracking.
DO NOT DISTURB clear plastic insulating
cover (flash shield) which protects magnetic
pick-up module.
LUBRICATE DISTRIBUTOR ROTOR SPINDLE - V8i
Apply a spot of clean engine oil into rotor spindle after
rotor arm has been removed.
CLEAN/ADJUST SPARK PLUGS - V8i CATALYST
RENEW SPARK PLUGS V8i - V8i CATALYST
Clean, adjust and renew
1.Take great care when fitting spark plugs not to
cross-thread plug, otherwise costly damage to
cylinder head will result.

MAINTENANCE
19
MAINTENANCE
RESET EMISSION MAINTENANCE REMINDER -
USA
The emission maintenance reminder is designed to
activate at 52,500 and 105,000 miles respectively and
will illuminate a 'Service Engine' red warning light in
instrument binnacle.
The emission maintenance reminder must be reset
after required maintenance has been carried out and
a new tamperproof label fitted by a Land Rover of
North America dealer. This emission maintenance
reminder is part of the Emission Control System
Reset
1.The control unit is located in the passenger
footwell.
2.Identify control unit and remove from plug.
3.Remove tamperproof label to reveal access hole
for resetting.
4.Place a thin metallic probe into access hole and
momentarily electrically short between reset pins
inside unit.RECOMMENDED SERVICE ITEMS
Refer Service Schedule sheets for intervals.
Clean sunroof drain tubes, clean and lubricate guide
rails and slides.
Renew the hydraulic brake fluid.
See BRAKES,
Repair, Brake System Bleed
Renew all hydraulic brake fluid, seals, brake servo
filter and flexible hoses.
All working surfaces of the master cylinder and caliper
cylinders should be examined and renewed where
necessary.
ABS vehicles only - renew hydraulic brake fluid and
flexible hoses examine the working surfaces of the
caliper cylinders and renew the seals or cylinders
where necessary.
Air cleaner - When the vehicle is used in dusty or field
conditions or deep wading, frequent attention to the
air cleaner may be required.
ABS vehicles used extensively in arduous off-road
conditions - check the rear wheel road speed sensor
for abrasive wear.

EMISSION CONTROL
1
FAULT DIAGNOSIS REV: 09/95 TESTING EVAPORATIVE EMISSION CONTROL -
PRE ADVANCED EVAPS
The following pressure test procedure is intended to
provide a method for ensuring that the system does
not leak excessively and will effectively control
evaporative emissions.
Equipment required.
Nitrogen cylinder (compressed air may be used to
pressure the system when there has NEVER been
fuel present in the fuel or evaporative control
systems).
Water manometer (0 - 30" H2O or more).
Pipework and a "T" piece.
Method.
1.Ensure that there is at least two gallons of fuel in
the petrol tank unless there has never been any
fuel in the system.
2.Disconnect, at the adsorption canister, the pipe
to the vapour separator.
3.Connect this pipe to the nitrogen cylinder and
the water manometer using the "T" piece.
4.Pressurize the system to between 26.5 and 27.5
inches of water, allow the reading to stabilize,
then turn off the nitrogen supply.
5.Measure the pressure drop within a period of 2
minutes 30 seconds. If the drop is greater than
2.5 inches of water the system has failed the
test. Note that a fully sealed system will show a
slight increase in pressure.
6.Should the system fail the test, maintain the
pressure in the system and apply a soap
solution round all the joints and connections until
bubbles appear to reveal the source of the leak.
7.Repeat the test and if successful, dismantle the
test equipment and reconnect the pipe to the
adsorption canister.LEAK DETECTION PROCEDURE - ADVANCED
EVAPS
1.Connect TestBook to the vehicle and confirm
that the fault code(s) displayed relate to an
EVAP system fault.
2.Examine components in fuel and EVAP system
for damage or poorly connected joints.
3.Repair or replace components to rectify any
faults found, then reset the Check Engine light
using TestBook.
4.Carry out Drive Cycle,
See Drive Cycle -
Advanced EVAPS
5.Using TestBook confirm that the Evaporative
Loss Control (ELC) Inspection and Maintenance
(IM) flag has cleared. This procedure should
confirm that the ELC test was carried out during
the drive cycle and that the fault was cured.
6.If the IM flag is still shown, use TestBook to
interrogate the engine management system to
ascertain which of the following situations exists:
·If a fault code is shown then further investigation
is required, proceed to the next step.
·If the IM flag is still shown, but no faults are
indicated the conditions for the ELC check have
not been met and the drive cycle must be
repeated.
7.Connect the Leak Detection/EVAP Diagnostic
Station to the vehicle and carry out the
procedures given in the operating instructions
supplied with the equipment.
8.Rectify faults indicated by the Leak
Detection/EVAP Diagnostic Station and return to
step 4.

MFI
3
DESCRIPTION AND OPERATION Tune select resistor -
To suit individual market requirements a tune select
resistor is connected across pins 5 and 27 of the
ECM.
It is located adjacent to the ECM, and strapped to the
MFI cable assembly. The value of the resistor is
dependent on the market application:
Red wire, 180 ohms, Australia, Rest of world.
Green wire, 470 Ohms, UK and Europe - non catalyst.
Yellow wire 910 Ohms, Saudi non catalyst.
White wire, 3K9 Ohms, European catalyst
Condenser fans
It should be noted that under high coolant
temperatures, when the engine is switched off, the
condenser fans will be activated and will run for
approximately ten minutes.Vehicle speed sensor
The vehicle speed sensor is located on the side of the
Transfer box adjacent to the parking brake. The
sensor provides road speed data to the ECM. The
ECM in turn detects vehicle movement from the road
speed input and ensures that idle air control mode is
disengaged. Should the vehicle speed sensor fail in
service the ECM idle air control would become erratic.
The sensor also provides road speed data to the
electric speedometer and cruise control ECU.
Inertia fuel shutoff switch
The inertia fuel shutoff switch is a mechanically
operated switch, located on the bulkhead adjacent to
the washer reservoir under bonnet [hood].
The switch is normally closed and is in line with the
fuel pump. In the event of a sudden impact the switch
opens, and disconnects the electrical feed to the fuel
pump. The switch is reset by pressing down the
button.
WARNING: Check the integrity of the fuel
system before the inertia switch is reset.
Relay modules
The two multiport fuel injection relays are located in
the RH footwell area behind the 'A' post panel. The
main relay module is energized via the ECM when the
ignition is switched on and supplies current to the
multiport fuel injection system. The fuel pump relay
module is energized by the ECM which in turn
operates the fuel pump to pressurize the fuel system.

SFI
7
DESCRIPTION AND OPERATION REV: 09/95 Fuel pressure regulator
The fuel pressure regulator is located at the rear of
the engine in the fuel rail. It consists of a fuel inlet,
outlet, vacuum port and internal diaphragm.
When the engine is under high manifold depression,
the applied vacuum sucks the diaphragm of its seat,
allowing fuel to return to the tank, resulting in a lower
fuel pressure. This is necessary because the high
depression will try to suck the fuel from the injector,
resulting in overfuelling if the pressure remained
constant. Failure will result in a rich mixture at idle but
normal at full load, or a rich mixture resulting in engine
flooding, or a weak mixture. Although the fault will not
illuminate the MIL, faults caused by the failure may be
indicated.Relay module
The engine management system employs a relay
module, which houses the main relay and the fuel
pump relay.
Main relay
The main relay supplies the power feed to the ECM
with a tap off to feed the fuel injectors (8 amps) and
air flow sensor (4 amps). This relay is controlled by
the engine management ECM. This enables the ECM
to remain powered up after ignition is switched off.
During this 'ECM power down routine' the ECM
records all temperature readings and powers the
stepper motor to the fully open position. Failure of this
relay will result in the engine management ECM not
being switched on resulting in engine not starting due
to absence of fuel and ignition.
Fuel pump relay
The fuel pump relay is fed from the ignition relay and
controlled by the engine management ECM. The relay
is activated in ignition key position 2 to prime the fuel
system for a period of time controlled by the ECM.
Failure of this relay will result in no fuel pressure.
Inertia switch
The inertia switch isolates the power supply to the fuel
pump in the event of sudden deceleration. The inertia
switch is located in the engine compartment. It is reset
by depressing the central plunger at the top of the
switch.

Mpi
5
DESCRIPTION AND OPERATION
Fuel pump
The electric fuel pump, located inside the fuel tank, is
a self-priming centrifugal 'wet' pump, the motor and
pump are filled with fuel.
The fuel pump supplies more fuel than the maximum
load requirement for the engine, so that pressure in
the fuel system can be maintained under all
conditions.
Fuel pressure regulator
The pressure regulator is a mechanical device
controlled by manifold depression and is mounted in
the fuel rail. The regulator ensures that fuel rail
pressure is maintained at a constant pressure
difference to that in the inlet manifold, as manifold
depression increases the regulated fuel pressure is
reduced in direct proportion.
When pressure exceeds the regulator setting excess
fuel is spill returned to the fuel tank swirl pot which
contains the fuel pick-up strainer.
Relay module
The relay module contains the main relay, fuel pump
relay, starter relay and oxygen sensor relay and is
mounted on the ECM mounting bracket.
The main relay is energised when the ignition is
switched on and supplies current to the ECM
The fuel pump relay is energised by the ECM for a
short period when the ignition is switched on, during
cranking and while the engine is running.
The starter relay is energised by the cranking signal
from the ignition switch.
This oxygen sensor relay is energised when the
ignition is switched on and supplies current to the
ECM
Intake air temperature sensor
The intake air temperature sensor is fitted in the side
of the inlet manifold and sends the ECM a signal
relating to air temperature. The ECM uses this signal
in its calculations on air flow.
Inertia switch
The fuel pump circuit incorporates an inertia switch
which in the event of sudden deceleration isolates the
power supply to the fuel pump. The inertia switch is
situated in the engine compartment on the bulkhead
and can, if tripped, be reset by depressing the central
plunger.
WARNING: Check the integrity of the fuel
system before the inertia switch is reset.
Diagnostic connector
A diagnostic connector is provided to enable
diagnosis to be carried out without disturbing the
system electrical connections and to allow the ECM's
ability to store certain faults to be utilised.
Oxygen sensor - Closed-loop emission control
The MEMS Mpi system operates a closed loop
emission system to ensure the most efficient level of
exhaust gas conversion.
An oxygen sensor fitted in the exhaust manifold
monitors the exhaust gases. It then supplies a small
voltage proportional to exhaust oxygen content to the
ECM As the air/fuel mixture weakens, the exhaust
oxygen content increases and so the voltage to the
ECM decreases. If the mixture becomes richer so the
oxygen content decreases and the voltage increases.
The ECM uses this signal voltage to determine the
air/fuel mixture being delivered to the engine, and
adjusts the injector duration to maintain the ratio
necessary for efficient gas conversion by the catalyst.
The oxygen sensor has an integral heating element to
ensure an efficient operating temperature is quickly
reached from cold. The electrical supply for the heater
element is controlled by the oxygen sensor relay.
Fuel temperature sensor
The fuel temperature sensor is inserted in the fuel rail
and measures fuel and fuel rail temperatures. During
engine cranking at high temperatures, the ECM
increases fuel supply, and opens the throttle disc via
the stepper motor to aid hot starting.

STEERING
9
FAULT DIAGNOSIS POWER STEERING SYSTEM - EXCESSIVE NOISE
1.Is fluid level correct?
YES - go to 3.
NO - Refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Is problem resolved?
YES - end
NO - continue.
3.Is pressure hose from pump to box touching
body in a hard foul condition?
YES - reroute hose away from body.
NO - go to 5.
4.Does noise remain?
YES - continue.
NO - end.
5.Is noise a whistle or hiss on full lock?
YES - noise is not a fault unless excessive.
Compare with other vehicles
NO - go to 8.
6.Is noise excessive?
YES - continue.
NO - end.
7.Change steering box and/or pump.
8.Is noise a squeal on full lock?
YES - check/reset drive belt tension.
See
ENGINE, Repair, Drive Belt
NO - go to 10.
9.Does squeal remain?
YES - drive belt contaminated, change belt.
NO - end.
10.Is noise a continuous moan?
YES - bleed PAS system.
See Repair, Power
Steering System - Bleed
NO - go to 13.
11.Does moan remain?
YES - do figure 8 manoeuvres.
NO - end.
12.Does moan remain?
YES - continue
NO - end.13.Is noise an intermittent "grunt"?
YES -
See Power Steering System - Grunt
NO - continue.
14.Is it a clunking noise?
YES - reset drive belt tension.
See ENGINE,
Repair, Drive Belt
NO - contact local technical office.
15.Does noise remain?
YES - Suspect suspension or drive train.
NO - end.
POWER STEERING SYSTEM - GRUNT
Steering box grunts intermittently when turning
from lock to lock:
1.Is fluid level correct?
YES - go to 3.
NO - refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Does grunt remain?
YES - continue
NO - end.
3.Is correct low pressure hose ANR 3152, steering
box to reservoir fitted?
YES - go to 5.
NO - Fit correct hose.
4.Does grunt remain?
YES - continue
NO - end.
5.Purge box by doing figure 8 manoeuvres e.g. on
car park, followed by 10 minutes normal road
use.
6.Does grunt remain?
YES - Contact local technical office
NO - end.

STEERING
11
FAULT DIAGNOSIS STIFF STEERING CHECKLIST
NOTE: Having completed visual checks
and steering assessment and confirmed
that vehicle steering load is incorrect carry
out the following procedure in order shown.
Steering wheel 'torque to turn' loads
1.Raise vehicle so both front wheels free.
2.With engine off, centralise steering wheel, and
remove air bag, if fitted or steering wheel pad.
Using torque wrench on column nut, check
torque required to turn the steering wheel one
turn in each direction.
3.Record readings obtained in each direction.
Compare figures obtained with the specified
figures:
Without ABS
4.40 Nm.
With ABS4.65 Nm.
NOTE: If figures are in excess of those
specified carry out steering box tie bar
reset below. If figures are as specified.
See Visual Check and Basic Adjustments
Steering box tie bar reset
1.Loosen the three tie bar fixings one complete
turn.
2.Drive vehicle carefully a short distance (within
the dealership) applying full lock in both
directions in order to settle steering components.
Drive vehicle over speed bumps and include
harsh braking if possible.
WARNING: Do not drive on public
highway.
3.Near end of 2. ensure vehicle is driven in a
straight line on level ground and halted.
4.Tighten panhard rod mounting arm nut,
110 Nm.
5.Tighten the two fixings tie bar to steering box,81
Nm.
6.Recheck steering wheel torque to turn. If torque
reading is still greater than specified, carry out
steering shaft universal joint lubrication.Lower steering shaft universal joint lubrication
1.Check lower steering shaft is correctly phased.
See Repair, Lower Steering Shaft and
Universal Joints
2.Lubricate universal joints with an anti-seizure
type penetrating spray. Work the joints to ensure
full penetration of the spray by driving vehicle
and steering from lock to lock.
3.If steering stiffness still persists carry out swivel
pin preload setting.
Swivel pin preload setting
The swivel pin preload setting must be checked and
set following the workshop manual procedure.
1.NON ABS vehicles.
See FRONT AXLE AND
FINAL DRIVE, Overhaul, Front Stub Axle,
Constant Velocity Joint and Swivel Pin
Housing Non ABS
Note that a pull load of 1.16 - 1.46 kg is required
after the axle shaft and swivel housing seal have
been removed.
2.ABS vehicles.
See FRONT AXLE AND FINAL
DRIVE, Overhaul, Front Stub Axle, Constant
Velocity Joint and Swivel Pin Housing ABS
Note that a torque to turn of 2.0 - 2.8 Nm is
required after the axle shaft and swivel housing
seal have been removed.
3.If steering stiffness still persists carry out
steering column alignment.

86ELECTRICAL
2
DESCRIPTION AND OPERATION ANTI-THEFT SYSTEM FUNCTION
Perimetric protection
Using the key in the correct sequence will turn on and
off perimetric protection only. When fully perimetrically
armed, all doors, and bonnet [hood] are protected
against unauthorised access. If the door key is used in
the normal manner the driver will be unaware of the
door key sequence. The time taken to lock or unlock
with the key must be less than 5 seconds. To prevent
unauthorised tampering, the alarm will sound if the
key is held in the unlocked position for longer than 5
seconds when armed. Cranking is disabled when
perimetric protection is armed.
NOTE: When key is turned left or right the
keyswitch input will be activated, in
conjunction with the sill button switch
when links are operated.
Volumetric protection
Using the handset transmitter will turn on and off
volumetric protection. In volumetric mode the vehicle
interior is protected using the ultrasonic sensor. Using
the handset also arms and disarms the vehicle
perimetrically. Cranking is disabled when volumetric
and perimetric protection is armed.
NOTE: If armed volumetrically the vehicle
CANNOT be disarmed using the key.
Alarm horn
When an intrusion is detected the alarm horn will
sound intermittently (Switzerland and Denmark
continuous horn sound) and the hazard lights flash
(where territorial regulations allow) for 30 seconds.
The alarm must be retriggered before alarm horn will
sound again.Vehicle status indication
Vehicle status is indicated by up to three devices: (a)
alarm horn, (b) hazard lights, (c) dash board LED.
When the vehicle arms in either mode the hazard
lights will flash three times and the LED will flash
rapidly for 10 seconds. LED will then flash at a slower
rate while vehicle is armed. When the vehicle disarms,
hazard lights will flash once and LED will extinguish. If
LED remains lit, it indicates that the alarm has been
triggered. Turning on ignition or arming the alarm will
extinguish LED. The LED will give a long pulse flash
to indicate the ultrasonic unit being activated.
Central locking
Central locking is controlled by the alarm ECU and
may be operated by the key, sill button(s) or handset.
The system works on both front doors on four door
vehicles or driver's door on two door vehicles.
NOTE: The central door locking system
will shut down for a short period after
more than 15 consecutive operations.
Inertia switch
An inertia switch is incorporated in the alarm system
ECU. If ignition is on and the vehicle receives an
impact sufficient to activate the inertia switch, the ECU
will signal to unlock central locking actuators and flash
hazard lights. Central locking will remain disabled for
30 seconds. To reset turn ignition off and then on after
the 30 second period has elapsed.
Ultrasonic unit
The unit operates by emitting an air pressure carrier
wave and receiving the wave back. Any disturbance
within the vehicle which disturbs the wave will be
detected, triggering the alarm.
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 within the vehicle it delays arming
until a 15 seconds quiet period has elapsed. If
continuous movement is detected the alarm will not
arm volumetrically.

86ELECTRICAL
12
REPAIR FRONT DOOR ACTUATOR UNIT
Service repair no - 86.26.08
Remove
1.Ensure that the window glass is in its fully closed
position.
2.Disconnect battery negative lead.
3.Remove the door pull, trim panel and plastic
vapour barrier.
See CHASSIS AND BODY,
Repair, Front Door Trim Panel
4.Remove the lower two screws and plain washers
securing the actuator mounting plate to the inner
door panel.
NOTE: The upper two actuator mounting
plate securing screws also secure one of
the door pull mounting brackets and
locate with a nut retainer strip fitted on the inside
face of the inner door panel.
5.Remove the upper two screws, the door pull
mounting bracket and retrieve the nut retaining
strip from inside the door.
6.Release the window lift motor leads from the
three clips at the front of the door to allow
sufficient slack in the harness for actuator
assembly removal.
7.Detach actuator assembly operating rod from the
actuator link on the door lock.8.Withdraw the actuator assembly from the door
until the electrical cable is pulled out of its
channel sufficiently to expose the connector.
9.Detach the connector and remove the actuator
from the door.
10.The actuator unit may be changed by removing
the two rubber mounted screws that secure it to
the mounting plate.
Refit
11.Attach the actuator assembly connector to its
mating half on the door harness.
12.Engage the actuator assembly operating rod
with the hooked end of the actuator link.
13.Pull the door harness back into its channel from
the front end and secure the window lift motor
leads with the three clips.
14.Fit the actuator assembly to the inner door panel
and loosely secure with the two lower screws
and plain washers.
15.Position the nut retainer on the inside face of the
inner door panel, locate the door pull mounting
bracket and loosely secure with the two upper
screws.
16.Set the actuator mounting plate with the screws
in the centre of the slotted holes, then tighten the
screws sufficiently to retain the assembly.
17.Ensure that manual operation of the sill locking
control is not restricted by the operation of the
actuator operating rod and vice versa, resetting
the mounting plate as necessary.
18.Reconnect battery negative lead.
19.Check that electrical operation of the door lock
occurs when the sill locking control is moved
through half of its total movement. Reset the
mounting plate as necessary and fully tighten the
four screws.
NOTE: The above adjustment ensures that
the full tolerance on the switching
operation is utilised.