diagram LAND ROVER DISCOVERY 1995 Service Repair Manual

01INTRODUCTION
16
INFORMATION FAULT DIAGNOSTIC EQUIPMENT
TESTBOOK
Todays Land Rover Vehicles are equipped with a
large amount of electronics to provide the best
performance of the vehicles systems.
Diagnostic equipment named TESTBOOK is available
to expand the diagnostic abilities of the dealer
workshop. This repair manual is produced with
Testbook in mind.
Features of Testbook include :- Fully upgradable
support for the technician. Structured diagnostics to
accommodate all skill levels. Touch screen operation.
Direct print out of screen information and test results.
ELECTRICAL TROUBLESHOOTING MANUAL
The Electrical Troubleshooting Manual is a separate
publication that is intended for use by trained Land
Rover technicians as an aid to diagnosing electrical
concerns.
It provides circuit diagrams, system diagnosis flow
charts, electrical component location tables, electrical
component location views and circuit operation
details.READING THIS MANUAL
This manual is divided into sections shown on the
contents page, alongside a range of icons, familiar to
service technicians.
Relevant information is contained within each of these
sections. These are further divided into the following
sub-sections which appear at the foot of each page :-
Description and operation.
Fault diagnosis.
Adjustment.
Repair.
Overhaul.
Specifications, Torque.
Service tools.
To avoid repeating information through the sections,
where part of the repair operation impacts on another
section, a cross reference is given to direct the reader
to where the information is sited.
For example:
The maintenance section states the need to renew
V8i drive belt. A cross reference sites this information
in: Section: V8i Engine
- Sub-section: Repairs
- Heading: Drive belt renew.
Sections that contain derivatives such as engines are
further separated within that section.
American terminology.
A few words used in this manual differ to words used
in America. Where this occurs the American word is
placed inside brackets. For example: bonnet [hood],
wing [fender], ramp [hoist].

70BRAKES
2
DESCRIPTION AND OPERATION ABS COMPONENTS
Location
Key to diagram
1. ABS Modulator unit
2. Servo/Master cylinder
3. Pressure reducing valve
4. Electronic control unit5. Rear sensors/exciter rings
6. Front sensors/exciter rings
7. Diagnostic plug connection

82AIR CONDITIONING
4
FAULT DIAGNOSISFAULT CAUSE REMEDY
E.
NOISY
EXPANSION
VALVE
(steady hissing)1. Low refrigerant charge; evident by
bubbles in sight glass.1. Leak test. Repair or replace
components as required.
F.1. Expansion valve not operating 1. Refer to C-2, C-3, D-1
INSUFFICIENTproperly. and E.
COOLING2. Low refrigerant charge-evident 2. Refer to B-1 and E.
by bubbles in sight glass.
3. Compressor not pumping. 3. Refer to B-2 and B-3
G.1. Belt tension. 1. Adjust belt tension.
COMPRESSOR2. Excessive head pressure. 2. Refer to A-1 through
BELTA-4 and C-6.
SLIPPING3. Incorrect alignment of pulleys 3. Repair as needed.
or worn belt not riding properly.
4. Nicked or broken pulley. 4. Replace as needed.
5. Seized compressor. 5. Replace compressor.
1. Loose or missing mounting bolts. 1. Repair as necessary.
2. Broken mounting bracket. 2. Replace bracket.
3. Loose flywheel or clutch 3. Repair as necessary.
retaining bolt.
H.4. Rough idler pulley bearing. 4. Replace bearing.
ENGINE5. Bent, loose, or improperly 5. Repair as necessary.
NOISEmounted engine drive pulley.
AND/OR6. Defective compressor bearing. 6. Replace bearing.
VIBRATION7. Insecure mountings of 7. Repair as necessary.
accessories; generator, power
steering, air filter, etc.
8. Excessive head pressure. 8. Refer to A-1, A-2, A-3
A-4 and C-6.
9. Incorrect compressor oil level. 9. Refer to compressor Oil
Level Check.
HEATER AND AIR CONDITIONING - CIRCUIT
DIAGRAMS
1.For details of heating and air conditioning
electrics
See Electrical Trouble Shooting
Manual.

86ELECTRICAL
10
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.

ELECTRICAL
1
FAULT DIAGNOSIS GENERAL INFORMATION
The electrical fault diagnostic tool on Discovery
vehicles is Testbook. Detailed information of electrical
systems, component locations and circuit diagrams
are covered in the Discovery Electrical
Troubleshooting Manual.
See INTRODUCTION,
Information, Fault Diagnostic Equipment
This section covers checks of the charging and
ignition system.
GENERATOR TESTING
Service repair no - 86.10.01
Charging system check
1.Check battery is in good condition, with an open
circuit voltage of at least 12.6 V. Recharge or
substitute battery to carry out test.
2.Check drive belt condition.
See SECTION 10,
Maintenance, Under Bonnet [Hood]
Maintenance
3.Check battery connections are clean and tight.
4.Check generator connections are clean and
tight.
5.Ensure there is no drain on battery from, for
example, interior, under bonnet [hood] or door
edge lamps.
Generator test
Following instructions refer to use of suitable test
equipment using a carbon pile rheostat.
6.Connect test equipment referring to
manufacturer's instructions.
7.Start engine and run at 3000 rev/min without
accessory load.
8.Rotate carbon pile load control to achieve
greatest output (amps) without allowing voltage
to fall below 12.0 V. A reading in amps, of
generator output, minus 10% to allow for EFI
and Ignition loss, should be obtained.
9.Run engine at 3000 rev/min, switch selector to
regulator test, read voltmeter. A reading of 13.6
to 14.4 V should be obtained.
10.Switch selector to diode/stator test, switch on
headlamps to load generator. Raise engine
speed to 3000 rev/min, read voltmeter, needle
must be within 'OK' range.TESTING IN POSITION
Charging circuit resistance test.
1.Connect a low range voltmeter between
generator terminal marked B+ and positive
terminal of battery.2.Switch on headlamps, start engine. Run engine
at approximately 3000 rev/min. Note voltmeter
reading.
3.Transfer voltmeter connections to frame of
generator and negative terminal of battery, and
again note voltmeter reading.
4.If reading exceeds 0.5 volt on positive side or
0.25 volt on negative side, there is a high
resistance in charging circuit which must be
traced and remedied.