ECU LAND ROVER DISCOVERY 1995 Workshop Manual

19FUEL SYSTEM
6
REPAIR VACUUM PUMP - TDI
Service repair no - 19.75.06
NOTE: The vacuum pump is non
serviceable, fit a new unit if failure or
damage occurs.
Remove
1.Release turnbuckle securing wheel chock and
remove.
2.Release strap securing jack and remove.
3.Release 3 pump mounting rubbers from vehicle
body.
4.Manoeuvre pump out of box section.
5.Release multiplug cover and disconnect
multiplug from pump.
6.Disconnect vacuum hose from pump.
7.Remove pump.
Refit
8.Reverse removal procedure. Ensure all hose
and electrical connections are secure.

CRUISE CONTROL
7
REPAIR CRUISE CONTROL ECU - V8i
Service repair no - 19.75.49
Remove
1.Remove lower dash panel.
2.Disconnect ECU multi-plug.
3.Remove ECU fixing.
4.Remove ECU.
5.Reverse removal procedure. Ensuring that
electrical multi-plug is securely reconnected.
SPEED TRIP ECU - MANUAL V8i
NOTE: The neutral lock out relay
module/speed trip ECU is mounted in the
right hand side footwell. To identify
components.
See Electrical Trouble Shooting
Manual.
VEHICLE SPEED SENSOR
Service repair no - 18.30.22
For Tdi
See FUEL SYSTEM Tdi, Repair, Vehicle
Speed Sensor
For V8iSee FUEL SYSTEM MFI, Repair, Vehicle
Speed Sensor
NEUTRAL LOCK OUT RELAY
Service repair no - 19.75.28
1.Remove 3 studs securing fascia right hand side
closing panel.
2.Release and move closing panel aside.
3.Remove 2 studs securing right hand side 'A' post
lower trim casing.
4.Remove casing.
5.Locate relay (neutral coloured base) and release
base from bracket.
6.Remove relay.
NOTE: For further information.See
Electrical Trouble Shooting Manual.
Refit
7.Reverse removal procedure.

19FUEL SYSTEM
8
REPAIR ACTUATOR - Tdi
Service repair no - 19.75.05
NOTE: The actuator is non serviceable, fit
a new unit if failure or damage occurs.
Remove
1.Disconnect battery negative lead.
2.Remove split pin, withdraw clevis pin and
disconnect cable from lever.
3.Disconnect link ball end from cable lever.
4.Disconnect vacuum hose from actuator.
5.Remove nut securing actuator to bracket and
remove actuator.
6.Inspect rubber diaphragm. Fit a new actuator
assembly if diaphragm is damaged.Refit
7.Check that link setting distance (dimension 'A')
equals 16 mm and that the retainer is locked in
position. If correct, proceed to paragraph 9.
8.If dimension 'A' is not correct, proceed as
follows:
·Measure 16 mm from diaphragm collar and
mark the position.
·Position link and retainer to the mark and
rotate retainer half a turn to secure.
·Check measurement 'A' is still 16 mm, then
turn retainer a further quarter turn to lock.
9.Fit actuator and secure to bracket with nut.
10.Connect vacuum hose.
11.Connect link ball end to cable lever.
12.Connect cable to lever and secure with clevis pin
and split pin.
13.Adjust cable position to remove any free play
from link, setting dimension 'B' should be 103
mm.

CRUISE CONTROL
9
REPAIR CRUISE CONTROL ECU - Tdi
Service repair no - 19.75.49
Remove
1.Remove 4 studs securing fascia left hand
closing panel.
2.Remove closing panel.
3.Remove nut securing ECU/relay bracket.
4.Lower bracket for access.
5.Remove bottom nut securing ECU to bracket.
6.Open glove box, align stops with cut-outs in
fascia panel and lower.
7.Move SRS harness aside.
8.Remove top nut securing ECU to bracket.
9.Disconnect ECU multiplug.
10.Remove ECU.
Refit
11.Reverse removal procedure. Ensure electrical
multiplug is securely reconnected.

26COOLING SYSTEM
2
DESCRIPTION AND OPERATION VISCOUS FAN
Description
The viscous drive unit for the engine cooling fan,
provides a means of controlling the speed of the fan
relative to the running temperature of the engine. The
viscous unit is a type of fluid coupling, which drives
the fan blades through the medium of a special
'silicone fluid' injected into the unit during
manufacture.
1. Drive in from water pump spindle
2. Drive out to fan blades
3. Bi-metalOperation
The viscous unit consists of two principal components:
An inner member 1 which is secured to water pump
spindle and is driven by the fan belt.
An outer member 2 which has the fan blades
attached, houses the working parts and is driven
through the medium of the viscous fluid.
The inner and outer members have interlocking
annular grooves machined in each, with a small
running clearance 3 to allow the silicone fluid to
circulate through the valve plate 4.
The unit also contains a valve 5 which is controlled by
an external bi-metal thermostat 6.
Starting engine from cold
During the time the engine is at rest the silicone fluid
drains down, half filling chambers A and B. Thus when
the engine is first started sufficient fluid is present in
chamber A to provide a positive drive between the
members, as is evident by the initial noise of the fan.
However within a very short period of time, after
starting the engine, the fan speed and noise will
decline indicating that the fluid is being centrifuged
into chamber B (as seen in RR3757M) causing the
drive to slip.

Tdi
1
REPAIR VISCOUS COUPLING, FAN BLADES, PULLEY AND
FAN COWL
Service repair no - 26.25.03/05
Viscous coupling -Remove1to3
Fan blades -Remove1to4
Fan cowl -Remove1to3
Fan pulley -Remove1to6
Remove
WARNING: Disconnect battery negative
terminal to prevent engine being started
before removing or adjusting drive belt.
1.Slacken nut securing viscous coupling/fan blade
assembly to pulley.
NOTE: Nut securing viscous unit to pulley
has a left hand thread. Release by turning
clockwise when viewed from front of
viscous unit.
2.Drop viscous unit and fan assembly into bottom
of cowling
3.Remove two fixings clips from top of cowling and
lift cowling complete with viscous unit and fan
out of lower mountings.
4.Remove fan blades from viscous coupling if
necessary.
5.Remove serpentine drive belt and, if fitted, air
conditioning compressor belt.
6.Remove pulley fixings, remove pulley.
NOTE: The serpentine belt is removed by
using a hexagonal socket and tommy bar
on the auto-tensioning pulley nut. Whilst
tensioning the device the belt can be removed.
7.Reverse removal procedure. Ensure fan blades
are fitted correctly. Fan is marked 'front' and
should be fitted with word 'front' closest to
radiator. Tighten to
30 Nm.
8.Refit drive belt.See ENGINE, Repair, Drive
Belt
THERMOSTAT
Service repair no - 26.45.01
Remove
1.Partially drain cooling system, until coolant level
is below thermostat housing.
2.Disconnect hose from thermostat housing.
3.Disconnect electrical connections to water
temperature switch.
4.Remove outlet elbow.
5.Withdraw thermostat.
Test
6.Note rating of thermostat is 88°C. Place
thermostat in a container half full of water. Heat
water, observe temperature at which thermostat
begins to open. Thermostat is satisfactory if its
open between 85°C and 89°C.
Refit
7.Insert thermostat with jiggle pin/vent hole upper
most (12 o'clock position) .
8.Fit the outlet elbow and new joint washer.
Tighten to
28 Nm.
9.Reverse removal procedure. 1 to 3.
10.Check for coolant leaks around all connections
and joint faces.

26COOLING SYSTEM
2
REPAIR WATER PUMP
Service repair no - 26.50.01
Remove
WARNING: Disconnect battery negative
terminal to prevent engine being started
before removing drive belts.
1.Drain engine cooling system.
See Adjustment,
Coolant
2.Remove top hose radiator to thermostat.
3.Remove top hose intercooler to induction
manifold.
4.Slacken water pump and power steering pump
pully retaining bolts.
5.Remove drive belt.
6.Remove centre nut from belt tensioner.
7.Manoeuvre pulley upwards and withdraw
tensioner from retaining stud.
8.Disconnect hose thermostat to bottom hose,
release hose from clip on water pump and move
aside.
9.Remove water pump pulley.
10.Remove power steering pump pulley.
11.Remove 8 bolts securing water pump, noting
location of 3 through bolts.
12.Withdraw pump and gasket, clean all gasket
material from mating surfaces.
Refit
13.Refit water pump in reverse order to removal
using new gasket.RADIATOR
Service repair no - 26.40.01
Remove
1.Drain cooling system.
See Adjustment,
Coolant
2.Disconnect radiator top hose.
3.Remove fan blade assembly.
4.Remove cowl.
5.Disconnect engine oil cooler connections and
turbo intercooler connections from radiator ends.
NOTE: Oil spillage will occur when
connections are loosened. Blank off
exposed oil connections.
6.Disconnect expansion tank bleed hose from
radiator.
7.Remove radiator securing brackets from each
side.
8.Remove radiator unit by lifting from its location.
Check condition of rubber mounting pads.
Refit
9.Check radiator sealing strips are securely
located.
10.Transfer oil cooler adaptors if fitting new radiator.
11.Reverse removal procedure. Tighten oil cooler
connections to
30 Nmbefore fitting fan blades
and cowl.
12.Check all connections for leaks.

26COOLING SYSTEM
4
DESCRIPTION AND OPERATION Operation
The viscous unit consists of two principal components:
An inner member 1 which is secured to water pump
spindle and is driven by the fan belt.
An outer member 2 which has the fan blades
attached, houses the working parts and is driven
through the medium of the viscous fluid.
The inner and outer members have interlocking
annular grooves machined in each, with a small
running clearance 3 to allow the silicone fluid to
circulate through the valve plate 4.
The unit also contains a valve 5 which is controlled by
an external bi-metal thermostat 6.
Starting engine from cold
During the time the engine is at rest the silicone fluid
drains down, half filling chambers A and B. Thus when
the engine is first started sufficient fluid is present in
chamber A to provide a positive drive between the
members, as is evident by the initial noise of the fan.
However within a very short period of time, after
starting the engine, the fan speed and noise will
decline indicating that the fluid is being centrifuged
into chamber B (as seen in RR3757M) causing the
drive to slip.
Viscous unit slipping (Engine at normal running
temperature)
1. Inner member (drive in fast)
2. Outer member (drive out slow)
3. Running clearance
4. Valve plate
5. Valve (closed)
6. Bi-metal
7. Fluid seals
8. Ball race
A. Fluid chamber
B. Fluid chamber
If the engine speed is increased the degree of slip will
also increase to limit the maximum fan speed.

V8i
1
REPAIR EXPANSION TANK
Service repair no - 26.15.01
Remove
WARNING: Do not remove expansion tank
filler cap when engine is hot. The cooling
system is pressurised and personal
scalding could result.
1.Remove expansion tank filler cap by first turning
it slowly anti-clockwise, pause to allow pressure
to escape. Continue turning in same direction
and lift off.
2.Disconnect two hoses from bottom of expansion
tank, allowing coolant to drain into a suitable
container.
3.Remove three fixing bolts, remove expansion
tank.
Refit
4.Reverse removal procedure.
5.Replenish cooling system.
6.Check for leaks around all hose connections.VISCOUS COUPLING, FAN BLADES, PULLEY AND
COWL
Service repair no - 26.25.19 - Viscous coupling
and fan assembly
Service repair no - 26.25.03 - Water pump pulley
Service repair no - 26.25.05 - Fan blades
Special tools:
LRT-12-093
LRT-12-094 - Viscous coupling removal
Remove
1.Disconnect battery negative lead.
NOTE: 4.0 V8 only:
Release coolant hose from cooling fan upper
cowl.
2.Release 2 clips securing cooling fan upper cowl.
Remove cowl.

26COOLING SYSTEM
2
REPAIR
3.Use LRT-12-093 to prevent coolant pump pulley
from turning and using LRT-12-094, unscrew
viscous coupling from water pump.
NOTE: Nut securing viscous unit to water
pump has a right hand thread. Release by
turning anti-clockwise when viewed from
front of viscous unit.
4.Remove fan and coupling assembly.
Do not carry out further dismantling if component
is removed for access only.
NOTE: Mark fan with reference to assist
refitting.
5.Remove 4 Allen screws securing blades to
coupling. Remove coupling.
6.Remove serpentine drive belt.
7.Remove pulley fixings, remove pulley.Refit
8.Clean fan blades and mating faces.
9.Fit fan blades to coupling. Secure with screws.
Tighten to
24 Nm.
10.Using LRT-12-093 and LRT-12-094, fit fan
assembly to pump. Tighten to
56 Nm.
11.Fit cooling fan upper cowl. Secure with clips.
12. 4.0 V8 only:Fit coolant hose to cooling fan upper
cowl.
13.Fit serpentine drive belt.
14.Fit pulley fixings, remove pulley.
15.Reconnect battery negative lead.