Land Rover Discovery 99my To 03my Electrical Library 3rd Edition Rover Manual

							Discovery
Electrical Library
LRL 0529 NDERL03MY  22/2/02  12:23 pm  Page 2 
						

							DISCOVERY 99MY to 03MY
ELECTRICAL LIBRARY
LRL0529ENG(3)
Published by Land Rover
© Land Rover 2003
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form, electronic, mechanical, 
recording or other means without prior written permission from Land Rover. 
						

							CONTENTS
DISCOVERY SERIES II 1
INTRODUCTION ........................................................................... 1.1
ABOUT THIS DOCUMENT  ............................................................................... 1.1
ELECTRICAL PRECAUTIONS  ......................................................................... 1.3
HARNESS REPAIRS  ........................................................................................ 1.6
ABBREVIATIONS ............................................................................................. 1.9
HOW TO USE THIS DOCUMENT  .................................................................. 1.11
FAULT DIAGNOSIS  ........................................................................................ 1.14
WIRE COLOUR CODES  ................................................................................. 1.15
FUSE DETAILS  ............................................................................  2.1
ENGINE COMPARTMENT FUSE BOX  ............................................................ 2.2
PASSENGER COMPARTMENT FUSE BOX  .................................................... 2.5
LH/RH SATELLITE FUSE BLOCKS (SEATS)  .................................................. 2.8
EARTH POINTS AND HEADER JOINTS  ....................................  3.1
DESCRIPTION AND OPERATION  ..............................................  4.1
ANTI-THEFT ALARM  ........................................................................................ 4.1
CENTRAL DOOR LOCKING (CDL)  .................................................................. 4.7
WINDOWS - FRONT  ....................................................................................... 4.11
WINDOWS - REAR  ......................................................................................... 4.14
SUNROOF ...................................................................................................... 4.19
MIRRORS ....................................................................................................... 4.24
FOLDING MIRRORS (JAPAN ONLY)  ............................................................. 4.29
ELECTRIC SEATS  .......................................................................................... 4.31
MANUAL SEATS ............................................................................................. 4.35
DIAGNOSTIC SOCKET  .................................................................................. 4.37
BODY CONTROL UNIT (BCU)  ....................................................................... 4.39
STARTING AND CHARGING - Td5  ................................................................ 4.40
STARTING AND CHARGING - V8  .................................................................. 4.44
ENGINE MANAGEMENT - Td5  ...................................................................... 4.47
ENGINE MANAGEMENT - V8  ........................................................................ 4.48
IGNITION AND SHIFT INTERLOCK (NAS/JAPAN ONLY)  ............................. 4.49
CRUISE CONTROL - V8 ENGINES  ............................................................... 4.53
CRUISE CONTROL - Td5 ENGINES .............................................................. 4.58
ELECTRONIC AUTOMATIC TRANSMISSION (EAT)  .................................... 4.59
ACTIVE CORNERING ENHANCEMENT (ACE)  ............................................. 4.63
SELF LEVELLING AND ANTI-LOCK BRAKING SYSTEM (SLABS)  .............. 4.66
ANTI-LOCK BRAKING SYSTEM (ABS)  .......................................................... 4.70 
						

							CONTENTS
2DISCOVERY SERIES II
SUPPLEMENTARY RESTRAINT SYSTEM (SRS)  ......................................... 4.75
AIR CONDITIONING (A/C)  ............................................................................. 4.77
HEATER BLOWER - FRESH/RECIRCULATED AIR MOTOR 
(NON A/C VEHICLES)  .................................................................................... 4.84
FUEL BURNING HEATER (FBH) - Td5 ONLY  ............................................... 4.87
COOLING FAN ................................................................................................ 4.89
HEATED REAR WINDOW (HRW)  .................................................................. 4.92
HEATED FRONT SCREEN (HFS)  .................................................................. 4.95
FRONT WIPERS AND WASHERS  ................................................................. 4.98
REAR WIPERS AND WASHERS .................................................................. 4.103
BRAKE/REVERSE LAMPS  ........................................................................... 4.107
HEADLAMP LEVELLING  .............................................................................. 4.110
LIGHTS ON ALARM  ...................................................................................... 4.112
HEAD/SIDE AND NUMBER PLATE LAMPS  ................................................ 4.114
FRONT FOG LAMPS  .................................................................................... 4.118
REAR FOG GUARD LAMPS  ........................................................................ 4.121
INDICATORS AND HAZARDS ...................................................................... 4.124
INTERIOR LAMPS  ........................................................................................ 4.129
INTERIOR ILLUMINATION  ........................................................................... 4.133
INSTRUMENTS ............................................................................................ 4.135
HORNS ......................................................................................................... 4.143
CLOCK .......................................................................................................... 4.144
CIGAR LIGHTER  .......................................................................................... 4.145
ACCESSORY SOCKET  ................................................................................ 4.147
IN-CAR ENTERTAINMENT (ICE)  ................................................................. 4.148
TRAILER SOCKET  ....................................................................................... 4.162
PARK DISTANCE CONTROL (PDC)  ............................................................ 4.163
CONNECTOR ...............................................................................  5.1
CIRCUIT REFERENCE NUMBERS  .................................................................. 5.1 
						

							INTRODUCTION
DISCOVERY SERIES II 1.1
INTRODUCTIONABOUT THIS DOCUMENT
GENERAL
This document is intended to assist in diagnosing electrical faults, and should be used in 
conjunction with the Electrical Circuit Diagrams. The document is divided into the following 
sections:
1.INTRODUCTION – includes Electrical Precautions, a list of Abbreviations and general 
information on how to use the document.
2.FUSE DETAILS – provides details of location, rating in Amperes and circuit(s) 
protected.
3.EARTH POINTS AND HEADERS – provides details of earth points, earth and power 
headers, including a plan view of the vehicle to aid location.
4.DESCRIPTION AND OPERATION – provides an explanation of how each of the 
systems operates.
5.CONNECTOR DETAILS – details of connectors including a location photograph, face 
view and pin-out table.
NOTE: Before starting electrical checks on the vehicle, ensure that the relevant mechanical 
functions operate satisfactorily.
References
References to the LH or RH side given in this document are made when viewing the vehicle 
from the rear.
Operations covered in this document do not include reference to testing the vehicle after 
repair. It is essential that work is inspected and tested after completion and, if necessary, a 
road test of the vehicle undertaken, particularly where safety related items are concerned.
CAUTION: Before undertaking any electrical work on a vehicle ALWAYS read the 
ELECTRICAL PRECAUTIONS. 
						

							INTRODUCTION
1.2DISCOVERY SERIES II
Battery voltage
Open Circuit Voltage Test
Before commencing diagnosis of electrical problems, verify the condition of the battery is 
acceptable by using the open circuit voltage test.
1. Switch off all electrical loads on the vehicle.
2. Adjust digital multimeter to read dc volts on the appropriate scale.
3. Connect test probes across battery terminals ensuring that polarity is correct and 
record the voltage displayed.
A reading of 12.3V or more is acceptable; any battery which reads less than this will 
need charging.
NOTE: If the vehicle has been used within a period of 8 hours prior to the test, surface 
charge must be removed from the battery by switching the headlamps on for approximately 
30 seconds. Wait a further 60 seconds before checking the open circuit voltage.
Battery voltage is used as a known reference for ascertaining whether or not circuits are 
receiving sufficiently high voltage for components to function correctly. This reference is only 
a guide since most electronic circuits are designed to function over a wide range of voltages. 
In addition, consideration must be given to readings affected by voltage drop across certain 
components and fluctuations due to cable lengths. 
						

							INTRODUCTION
DISCOVERY SERIES II 1.3
ELECTRICAL PRECAUTIONS
General
The following guidelines are intended to ensure the safety of the operator whilst preventing 
damage to the electrical and electronic components fitted to the vehicle. Where necessary, 
specific precautions are detailed in the relevant sections of this document, reference to 
which should be made prior to commencing repair operations.
Equipment – Prior to commencing any test procedure on the vehicle, ensure that the 
relevant test equipment is working correctly and any harness or connectors are in good 
condition. This particularly applies to mains lead and connections.
WARNING: Before commencing work on an ignition system, all high tension 
terminals, adapters and diagnostic equipment for testing should be inspected to 
ensure that they are adequately insulated and shielded to prevent accidental personal 
contact and to minimise the risk of shock. Wearers of surgically implanted pacemaker 
devices should not work in close proximity to ignition circuits or diagnostic 
equipment.
Polarity – Never reverse connect the vehicle battery and always observe the correct polarity 
when connecting test equipment.
High Voltage Circuits – Whenever disconnecting live ht circuits, always use insulated pliers 
and never allow the open end of the ht lead to come into contact with other components, 
particularly ECUs. Since high voltage spikes can occur on the terminals of the coil while the 
engine is running, exercise caution when measuring the voltage at these points.
Connectors and Harnesses – The engine compartment of a vehicle is a particularly hostile 
environment for electrical components and connectors. Always ensure these items are dry 
and oil free before disconnecting and connecting test equipment. Never force connectors 
apart either by using tools or by pulling on the wiring harness. Always ensure locking tabs 
are disengaged before removal and note orientation to enable correct reconnection. Ensure 
that any protective covers and substances are replaced if disturbed.
Before removing a faulty component, refer to the Workshop Manual for removal procedures. 
Ensure the ignition switch is turned to the OFF position, the battery is disconnected (see 
Battery Disconnecting) and any disconnected harnesses are supported to avoid any 
undue strain at the terminals. When replacing the component keep oily hands away from 
electrical connection areas and push connectors home until any locking tabs fully engage. 
						

							INTRODUCTION
1.4DISCOVERY SERIES II
Battery disconnecting
Before disconnecting the battery, switch off all electrical equipment. If the radio is to be 
serviced, ensure the security code has been deactivated. When the battery is disconnected, 
certain data such as radio code, clock time, °C/°F on ATC panel and adaptive setups will be 
lost. On vehicles with battery backed-up sounder (BBUS) fitted, if the battery is disconnected 
with the alarm armed, the BBUS will sound.
CAUTION: To prevent damage to electrical components, ALWAYS disconnect the 
battery when working on the vehicle electrical system. The earth lead must be 
disconnected first and reconnected last. Always ensure that battery leads are routed 
correctly and are not close to any potential chafing points.
Battery charging
Recharge the battery out of the vehicle and keep the top well ventilated. While being 
charged or discharged, and for approximately fifteen minutes afterwards, batteries emit 
hydrogen gas. This gas is inflammable.
Always ensure any battery charging area is well ventilated and that every precaution is taken 
to avoid naked flames and sparks.
Disciplines
Switch off ignition prior to making any connection or disconnection in the system as electrical 
surge caused by disconnecting live connections can damage electronic components.
Ensure hands and work surfaces are clean and free of grease, swarf, etc. as grease collects 
dirt which can cause tracking or high-resistance contacts.
When handling printed circuit boards, treat them as you would a disc – hold by the edges 
only; note that some electronic components are susceptible to body static.
Connectors should never be subjected to forced removal or refit, especially inter-board 
connectors, damaged contacts will cause short-circuit and open-circuit conditions.
Prior to commencing test, and periodically during test, touch a good earth, i.e. cigar lighter 
socket, to discharge body static as some electronic components are vulnerable to static 
electricity. 
						

							INTRODUCTION
DISCOVERY SERIES II 1.5
Grease for electrical connectors
Some under bonnet and under body connectors are protected against corrosion by the 
application of a special grease during production. Should connectors of this type be 
disturbed, repaired, or replaced, a grease of this type, available under part number BAU 
5811, should again be applied. Do not apply grease to any connectors that do not have 
grease applied as standard.
NOTE: The use of other greases must be avoided as they can migrate into relays, switches 
etc. contaminating the contacts and leading to intermittent operation or failure.