warning light LAND ROVER DISCOVERY 1995 User Guide

ZF
3
REPAIR 19.Disconnect rear propeller shaft to output flange,
and tie to one side.
20.Repeat instructions 18 and 19 on front propeller
shaft to main gearbox.
21.Remove bolts retaining silencer front and rear
securing brackets and tie silencer to one side.
22.Disconnect oil cooler feed and return pipes from
bottom and side of main gearbox.
23.Release cooler pipes from clamp at engine sump
and remove distance piece.
24.Blank pipe ends and unions.
25.Move oil cooler pipes clear of transmission and
tie aside.
26.Disconnect selector cable from operating lever.
27.Disconnect inhibitor switch at multiplug.
28.Attach adaptor plate to hoist.
29.Remove two bolts from transfer gearbox rear
cover.
30.Raise hoist to align adaptor plate with transfer
gearbox and transmission. Secure to transfer
gearbox at rear cover with two bolts removed.
31.Adjust hoist to take weight of transmission.
32.Remove nuts and bolts securing right transfer
gearbox mounting bracket to chassis.
33.Repeat for the left mounting bracket. Removal of
these fixings will also free speedometer
transducer bracket
34.Remove right side mounting bracket to flexible
mounting rubber retaining nut.
35.Lower hoist until rear brake drum clears
passenger footwell. Check engine does not
crush any components while lowering.
36.Remove clip and clevis pin from park brake
lever.
37.Remove clip securing outer brake cable
38.The park brake cable is now free.
39.Disconnect leads from transfer gearbox
temperature sensor and differential lock warning
light switch.
40.Remove ties securing breather pipes to harness.
41.Remove bell housing access plate complete with
gasket.
42.Rotate engine, using crankshaft pulley, until two
access holes are visible in drive plate/ring gear
assembly through bell housing bottom cover
opening.
43.Identify an access hole and bolt hole to aid
reassembly.
44.Remove bolts securing drive plate to convertor
through access holes.
45.Rotate crankshaft half turn to access and
remove remaining bolts.
46.Disconnect oil dipstick tube at main gearbox.
47.Remove bolt at bell housing and detach dipstick
tube. Blank pipe end and union.
48.Position hoist jack channel under engine and
support using a wooden block.
49.Remove bell housing to engine securing bolts,
also detach harness bracket from bell housing.
50.Ease transmission rearwards to allow access to
secure torque converter in bell housing.
51.Lower hoist and complete removal of
transmission.
Refit
52.Ensure torque converter is retained in bell
housing.
53.Secure transmission to adaptor plate on lifting
hoist.
54.Raise hoist and locate transmission with engine.
55.Remove torque converter retainer.
56.Complete attachment of transmission to engine
and fit bell housing bolts. Fit the dipstick tube
bracket and harness bracket to their respective
bolts.
57.Complete refitting by reversing removal
procedure. Note the following important points.
58.Drive plate to torque converter bolts are to be
coated with Loctite 290 prior to assembly.
59.Refill transfer and main gearboxes with correct
grade oil.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
60.Check operation of parking brake and adjust as
necessary.
See SECTION 10, Maintenance,
Vehicle Interior

STEERING
5
FAULT DIAGNOSIS Symptom :-
Steering excessively light/sensitive. Excessive
freeplay at steering wheel.
1.Are steering box adjustments correct?
NO -
See Adjustment, Power Steering Box
WARNING: Adjustments of steering box
should not be required while in warranty
period. If box is within warranty, it must be
returned to manufacturer. No attempt must be
made to introduce backlash.
YES - Suspect worn panhard rod or radius arm
bushes Check condition of ball joints and
the lower steering column shaft universal
joints for wear.
See Repair, Lower
Steering Shaft and Universal Joints
Symptom :-
Steering vibration, road wheel shimmy - wobble.
Vibration through the steering linkage powerful
enough to induce high frequency oscillation of the
steering wheel, is generally caused by out of balance
road wheels. However there are a number of other
possible causes of this symptom which if severe, may
be described as shimmy or wobble. Regardless of the
terminology used by the owner/driver to describe the
symptoms, the following diagnostic checks should be
carried out in the order presented.
1.Check the tyres and balance of the road wheels.
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres See
WHEELS AND TYRES, Fault diagnosis, Fault
- Symptoms See WHEELS AND TYRES,
Repair, Wheel Balancing
2.Check the steering hydraulic damper function.
See Steering Damper
3.Check steering column universal joints for wear
and correct alignment.
See Repair, Lower
Steering Shaft and Universal Joints
4.Check steering linkage ball joints for wear,
correct alignment and security, including steering
box and tie rod.
See Steering Linkage Inspect
5.Check all front suspension rubbers for wear.
Check all fixing torques, including radius arm
bushes, panhard rod and anti-roll [sway] bar.
See FRONT SUSPENSION, Repair, Panhard
Rod See FRONT SUSPENSION, Repair,
Radius Arm See FRONT SUSPENSION,
Repair, Anti-Roll[Sway] Bar Assembly See
FRONT SUSPENSION, Repair, Front Shock
Absorber
6.Fit new radius arm bushes using NTC 6860. Fit
harmonic damper if vehicle has air suspension.
Fit new nuts, bolts and washers.
7. Coil spring vehicles only- If problem persists
fit damper kit STC 241 (2 off front) and STC
1474 (2 off rear). Road test vehicle.
8.Check the power steering box adjustments and
operation.
See Overhaul, Power Steering Box
9.Check the hub bearing end floats and determine
the condition of the hub bearings. As applicable.
See FRONT AXLE AND FINAL DRIVE, Repair,
Front Hub Assembly
10.Check the resistance and condition of the
swivels.
See FRONT AXLE AND FINAL
DRIVE, Description and operation,
Description
If problem is not diagnosed: Repeat
checks starting at 1.
11.Carry out a full steering geometry check.
See
INTRODUCTION, Information, Steering

BRAKES
1
DESCRIPTION AND OPERATION BRAKES
Discovery vehicles have servo assisted brake
systems and the option of an anti-lock brake system.
Information in this section refers to components
relevant to both brake systems. Where the system
components are different they are referred to as ABS
or NON ABS
BRAKE SYSTEM NON ABS
Description
The servo assisted hydraulic braking system is the
dual line type, incorporating primary and secondary
hydraulic circuits.
NOTE: References made to primary or
secondary do not imply main service
brakes or emergency brakes but denote
hydraulic line identification.
The brake pedal is connected to a vacuum assisted
mechanical servo which in turn operates a tandem
master cylinder. The front disc brake calipers each
house four pistons, these pistons are fed by the
secondary hydraulic circuit. The rear disc brake
calipers each house two pistons, these are fed by the
primary hydraulic circuit via a pressure reducing valve.
A brake fluid level switch is incorporated into the
reservoir cap assembly, the switch will immediately
illuminate a warning light in the instrument binnacle
indicating low fluid or sudden fluid loss.
The brake fluid reservoir is divided, the section closest
to the servo feeds the primary circuit and the section
furthest from the servo feeds the secondary circuit.
Under normal operating conditions both the primary
and secondary circuits operate simultaneously on
brake pedal application. In the event of a failure in the
primary circuit the secondary circuit will still function. If
the secondary circuit fails the primary circuit will still
function. The brake pedal travel will be longer in the
event of a half system failure.If the servo should fail, both hydraulic circuits will still
function but would require greater pedal effort due to
the lack of vacuum assistance. The hand operated
parking brake acts on a brake drum at the rear of the
transfer gearbox and is completely independent of the
hydraulic circuits.
Hydraulic circuit non ABS
Key
A = Primary hydraulic circuit
B = Secondary hydraulic circuit
C = Pressure reducing valve

70BRAKES
4
DESCRIPTION AND OPERATION System description
The brake system consists of dual hydraulic circuits in
a front - rear split. That is individual circuits to front
and rear axles.
Wheelspeed signals are provided by the fitting of
exciter rings to axles and speed sensors.
An ABS stop light switch is fitted to provide a braking
signal to the ECU as well as operate the stop lights.
Electrical wiring is provided as necessary with system
relays and fuses. Discovery Electrical Troubleshooting
Manual gives the location and wiring circuits of these
components.
Visual warning of system malfunction is provided via a
warning light in the instrument panel.
Hydraulic circuit ABS
Key
A = Primary hydraulic circuit
B = Secondary hydraulic circuit
C = Pressure reducing valve
D = ABS ModulatorABS System operation
During normal braking the feel of the brake pedal on
vehicles equipped with ABS will be the same as that
on non ABS vehicles. During ABS cycling the driver
will experience feedback in the form of a pulsating
brake pedal and solenoid/pump motor noise from the
Modulator.
The system is fully automatic in operation both on and
off road, and will only act when the ECU detects that
ABS cycling is necessary. The ECU continually
monitors the operation of the system.
When starting the ABS system will go through a series
of self checks, including a check of the solenoid
valves/pump motor.
WARNING LIGHT
The warning light will be on during the self check
(1.3-2 secs). If no faults are stored in the memory the
light goes out for 0.5sec,then comes on again. It will
then remain on until the vehicle is driven faster than 7
kph/5mph. This is the only time that the light will be on
without indicating a problem.
Any faults detected by the ECU will cause the warning
light to illuminate indicating that the vehicle may not
have full ABS control.

BRAKES
1
FAULT DIAGNOSIS ABS FAULT DIAGNOSIS
If a fault has occurred, or has been identified by ECU
self diagnostic function and ABS warning light is
illuminated. The system and components must be
checked to locate and rectify fault, using Testbook
diagnostics.
NOTE: If warning lamp has indicated a
fault in system, and no fault code has been
stored in memory, cause of fault is:
a) Failure in electrical supply
b) Bad ECU ground
c) Faulty warning light relay
d) ECU not connected
Before commencing fault diagnosis procedure
following items must be checked:
1.Inspect all exposed cables for damage or
abrasion.
2.Check ground on ABS system.
3.Battery - state of charge.
4.Check hub end-float.
5.All ABS fuses and electrical connections.
Fault rectification
1.Complete harness should be replaced if faults
are found in wiring harness.
2.DO NOT use unspecified cables or connectors,
as this could jeopardise safe function of ABS.
3.DO NOT attempt to open sealed 35 way
connector to ECU.FAULT DIAGNOSIS PROCEDURE
NOTE: If ABS warning light illuminates due
to large sensor air gap, fault will be
retained by the ECU memory. Where wheel
sensors have been pushed fully home prior to
test, The ECU will indicate a fault that has been
rectified.
NOTE: After any steering adjustment,
bearing replacement/adjustment, brake
disc replacement: Check hub end-float and
sensor clearance.
RELAYS AND FUSES ABS
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment

70BRAKES
2
FAULT DIAGNOSIS ABS FAULT AND REMEDY CHART
SYMPTOM POSSIBLE CAUSE CHECK REMEDY
ABS warning light on ABS electrical fault Check ABS electrical
circuit with Testbook
diagnostic equipmentChange component if
necessary
High sensor air gaps Push in sensors
Brake fluid warning light
ONFluid loss Check reservoir fluid level
and inspect system for
leaksRectify leakage, refill
reservoir
Reservoir fluid level
switch malfunctionCheck fluid level switch Change reservoir
cap/switch
Pedal travel increased,
foot pressure normalAir in system Rebleed brake system
Master cylinder
malfunctionChange master cylinder
Pedal can be moved
downwards under
constant pressureSeal leaking in master
cylinderInspect system for leaks Change master cylinder
Seal leaking in servo unit Change servo unit

70BRAKES
18
REPAIR SENSORS - FRONT
Service repair no - 70.65.32
CAUTION: If a sensor is removed for any
reason, a NEW sensor bush and seal must
be fitted.
Remove
1.Disconnect battery negative lead.
2.Disconnect required sensor electrical
connection, located on inner wing [fender] panel.
3.Remove sensor lead from clips.
4.Clean area surrounding sensor to prevent
ingress of dirt. Using a suitable lever pry sensor
from mounting bush.
5.Release harness cable ties, remove sensor lead
from vehicle.
6.Remove top swivel retaining bolts complete with
brake jump hose and sensor seal. Remove
sensor bush.
Refit
7.Insert new sensor bush and seal.
8.Refit brake jump hose bracket, coat bolts with
Loctite 270.
9.Lightly coat new sensor using EP 90 oil. Push
sensor through bush until it contacts exciter ring.
Sensor will be 'knocked back' to correct position
when vehicle is driven.
10.Secure sensor lead in original position.
11.Reconnect sensor electrical connection.
12.Drive vehicle to ensure ABS warning light is
extinguished.
SENSOR RINGS
The rear sensor ring is assembled to the rear brake
disc to form part of the rear hub assembly.
See
REAR AXLE AND FINAL DRIVE, Repair, Rear Hub
Assembly
The front sensor ring is a toothed ring on the axle
shaft which forms part of the front stub axle assembly.
See FRONT AXLE AND FINAL DRIVE, Overhaul,
Front Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS

BRAKES
19
REPAIR SENSORS - REAR
Service repair no - 70.65.31
CAUTION: If a sensor is removed for any
reason, a NEW sensor bush must be fitted.
Remove
1.Disconnect battery negative lead.
2.Disconnect sensor electrical connections,
located above rear axle.
3.Remove sensor from its locating clip.
4.Remove bolts securing mudshield.
5.Using a suitable lever, pry sensor from mounting
bush.
6.Release harness cable ties, remove sensor lead
from vehicle.
7.Remove sensor bush.
Refit
8.Fit new sensor bush.
9.Lightly grease new sensor using silicone grease.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
10.Push sensor through bush until it touches exciter
ring. Sensor will be 'knocked back' to correct
position when vehicle is driven.
11.Secure harness in position.
12.Reconnect sensor electrical connection.
13.Drive vehicle to ensure ABS warning light is
extinguished.STOP LIGHT SWITCH ABS
Service repair no - 86.65.51
Remove
1.Turn ignition off. Disconnect battery negative
lead.
2.Remove lower trim panel.
3.Disconnect multiplug to switch.
4.Depress brake pedal access front of switch.
5.Pull sleeve and plunger of switch FULLY
forward.
6.Remove switch rearwards
NOTE: If switch is difficult to release,
check sleeve is FULLY forward.
Refit
7.Pull sleeve and plunger of switch fully forward.
8.Depress brake pedal, fit switch. Ensure retaining
clips are FULLY located.
9.Hold switch firmly in place, pull brake pedal back
fully to set switch.
10.Reconnect battery and turn ignition on.
11.Check switch operation by slowly depressing
brake pedal and checking that the switch clicks
twice.
12.Check stop lamps go off when pedal is released.
13.Recheck switch is securely fitted.
14.Operation may be checked using Testbook.

74WHEELS AND TYRES
6
REPAIR WHEELS
Remove
WARNING: The parking brake acts on
transmission, not rear wheels, and may
not hold vehicle when jacking unless
following procedure is used. If one front wheel
and one rear wheel is raised no vehicle holding or
braking effect is possible. Wheels MUST be
chocked in all circumstances.
Apply parking brake, select 'P' or a gear in main
gearbox and engage low gear in transfer box.
1.Loosen five wheel nuts.
2.Using a suitable trolley jack raise vehicle and
place on axle stands.
See INTRODUCTION,
Information, Jacking
3.Remove wheel nuts and carefully withdraw
wheel over studs.Refit
4.Ensure that retaining studs and nuts are clean.
5.Alloy wheels: Lightly coat wheel mounting spigot
face with a suitable anti-seize compound to
minimise possibility of adhesion between wheel
and spigot face.
6.Refit wheel taking care not to damage stud
threads. (Do not apply oil)
7.Fit wheel nuts and turn by hand for at least three
full threads before using any form of wheel
wrench.
8.Tighten nuts as much as possible using a
suitable wrench.
9.Lower vehicle and finally tighten nuts to correct
torque sequence shown. Alloy wheels and steel
wheels:
130Nm.

SUPPLEMENTARY RESTRAINT SYSTEM
1
DESCRIPTION AND OPERATION SYSTEM COMPONENTS
1. Airbag crash sensors (distributed SRS)
2. SRS warning light (airbag)
3. Rotary coupler
4. Driver's airbag module
5. Passenger's airbag module6. Airbag diagnostic socket
7. Airbag diagnostic control unit
8. Airbag harness (distributed SRS)
9. Knee bolsters (where fitted)
10. Airbag harness