Advanced automotive fault diagnisis : Automotive technology : Vehicle maintenance and repair

DIAGNOSTICS: TEST DON’T GUESS

Learn all the skills you need to pass Level 3 and Level 4 Vehicle Diagnostics courses from IMI, City & Guilds, and

BTEC, as well as ASE, AUR, and other higher-level qualifications.

Along with 25 new real-life case studies, this fifth edition of Advanced Automotive Fault Diagnosis includes

new content on diagnostic tools and equipment: VCDS, decade boxes, scanners, pass-through, sensor simulators,

breakout boxes, multimeter updates for HV use and more. It explains the fundamentals of vehicle systems and

components, and it examines diagnostics principles and the latest techniques employed in effective vehicle main￾tenance and repair. Diagnostics, or faultfinding, is an essential part of an automotive technician's work, and as

automotive systems become increasingly complex there is a greater need for good diagnostic skills.

Ideal for students, included throughout the text are useful definitions, key facts, and ‘safety first’ notes. This

text will also assist experienced technicians to further improve their performance and keep up with recent industry

developments.

Tom Denton has been researching and writing best-selling automotive textbooks for more than 25 years. His pub￾lished work is endorsed by all leading professional organisations and used by automotive students and technicians

across the world. His postgraduate education in all aspects of technology and education combined with many years

of practical industry experience have given him a broad base from which to approach and teach this interesting, yet

challenging, subject.

As a Fellow of the Institute of the Motor Industry and a Member of the Institute of Road Transport Engineers

and the Society of Automotive Engineers, he keeps in contact with the latest technologies and innovations across

all aspects of this fascinating industry. As well as publishing more than 30 textbooks, Tom has created amaz￾ing support materials and eLearning courses. Learn more about Tom's textbooks and his online Automotive

Technology Academy at:

www.automotive-technology.org.

Advanced Automotive

Fault Diagnosis

Advanced Automotive

Fault Diagnosis

Automotive Technology: Vehicle Maintenance and Repair

Fifth Edition

Tom Denton

Fifth edition published 2021

by Routledge

2 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN

and by Routledge

52 Vanderbilt Avenue, New York, NY 10017

Routledge is an imprint of the Taylor & Francis Group, an informa business

© 2021 Tom Denton

The right of Tom Denton to be identified as author of this work has been

asserted by him in accordance with sections 77 and 78 of the Copyright,

Designs and Patents Act 1988.

All rights reserved. No part of this book may be reprinted or reproduced or

utilised in any form or by any electronic, mechanical, or other means, now

known or hereafter invented, including photocopying and recording, or in any

information storage or retrieval system, without permission in writing from

the publishers.

Trademark notice: Product or corporate names may be trademarks or

registered trademarks, and are used only for identification and explanation

without intent to infringe.

First edition published by Elsevier 2000

Second edition published by Elsevier 2006

Third edition published by Routledge 2012

Fourth edition published by Routledge 2017

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library

Library of Congress Cataloging-in-Publication Data

Names: Denton, Tom, author.

Title: Advanced automotive fault diagnosis: automotive technology: vehicle

maintenance and repair / Tom Denton.

Description: Fifth edition. | Abingdon, Oxon; New York, NY: Routledge,

2021. | Includes index.

Identifiers: LCCN 2020015717 (print) | LCCN 2020015718 (ebook)

| ISBN 9780367330521 (paperback) | ISBN 9780367330545 (hardback)

| ISBN 9780429317781 (ebook)

Subjects: LCSH: Automobiles–Maintenance and repair. | Fault location

(Engineering)

Classification: LCC TL152 .D3934 2021 (print) | LCC TL152 (ebook)

| DDC 629.28/7–dc23

LC record available at https://lccn.loc.gov/2020015717

LC ebook record available at https://lccn.loc.gov/2020015718

ISBN: 978-0-367-33054-5 (hbk)

ISBN: 978-0-367-33052-1 (pbk)

ISBN: 978-0-429-31778-1 (ebk)

Typeset in Sabon LT Std

by Cenveo® Publisher Services

v

Contents

Preface xix

Acknowledgements xxi

1 Introduction

1

1.1 Diagnosis

1

1.1.1 What is needed to find faults?

1

1.2 Safe working practices

2

1.2.1 Introduction

2

1.2.2 Risk assessment and reduction

2

1.2.3 High voltage vehicles

2

1.2.4 IMI TechSafe™

4

1.3 Terminology

4

1.3.1 Introduction

4

1.4 Report writing

4

1.4.1 Introduction

4

1.4.2 Example report

5

1.4.2.1 Introduction

5

1.4.2.2 Test criteria

5

1.4.2.3 Facilities/Resources

5

1.4.2.4 Test procedures

5

1.4.2.5 Measured results

6

1.4.2.6 Analysis of results

6

1.4.2.7 Conclusions

6

2 Diagnostic techniques

7

2.1 Introduction

7

2.1.1 Logic

7

2.1.2 Data

7

2.1.3 Where to stop?

7

2.2 Diagnostic process

8

2.2.1 Six-stage process

8

2.2.2 The art of diagnostics

8

2.2.3 Concern, cause, correction

9

2.2.4 Root cause analysis 10

2.2.5 Summary 11

2.3 Diagnostics on paper 12

2.3.1 Introduction 12

2.3.2 Examples 12

2.3.3 How long is a piece of string? 12

vi Contents

2.4 Real-world diagnostics 13

2.4.1 Introduction 13

2.4.2 What do you know? 13

2.4.3 Training 13

2.4.4 The customer 13

2.4.5 How much does diagnostics cost? 14

2.4.6 How much should you charge? 14

2.4.7 Diagnostic sequence 16

2.4.8 Efficiency 17

2.4.9 Summary 17

2.5 Mechanical diagnostic techniques 17

2.5.1 Check the obvious first 17

2.5.2 Noise, vibration and harshness 18

2.5.3 Noise conditions 18

2.5.4 Vibration conditions 18

2.5.5 Road test 19

2.5.6 Engine noises 20

2.5.7 Sources of engine noise 20

2.6 Electrical diagnostic techniques 21

2.6.1 Check the obvious first 21

2.6.2 Test lights and analogue meters – warning 21

2.6.3 Generic electrical testing procedure 21

2.6.4 Volt drop testing 21

2.6.5 Testing for short circuits to earth 23

2.6.6 On and off load tests 23

2.6.7 Black box technique 23

2.6.8 Sensor to ECU method 24

2.6.9 Flight recorder tests 24

2.6.10 Faultfinding by luck – or is it logic? 24

2.6.11 Colour codes and terminal numbers 25

2.6.12 Back probing connectors 26

2.7 Systems 27

2.7.1 What is a system? 27

2.7.2 Vehicle systems 27

2.7.3 Open-loop systems 27

2.7.4 Closed-loop systems 28

2.7.5 Block diagrams 28

2.8 Pass-through 28

2.8.1 Overview 28

2.8.2 Software 30

3 Tools and equipment 31

3.1 Range of equipment 31

3.1.1 Introduction 31

3.1.2 Basic hand tools 31

3.1.3 Multimeter 31

3.1.4 Diagnostic scanners overview 32

3.1.4.1 VCDS 32

3.1.4.2 Snap-on Verdict 33

3.1.4.3 TopDon Artipad1 33

Contents vii

3.1.5 Oscilloscope 34

3.1.6 Breakout box 34

3.1.7 Battery tester 35

3.1.8 Insulation tester 36

3.1.9 Thermal camera 36

3.1.10 Sensor simulator 36

3.1.11 Actuator driver 37

3.1.12 Logic probe 37

3.1.13 Accuracy of test equipment 38

3.2 Multimeters 38

3.2.1 Introduction 38

3.2.2 Categories 40

3.2.3 Taking measurements 41

3.2.3.1 Voltage 41

3.2.3.2 Resistance 41

3.2.3.3 Current 41

3.2.4 What is an open circuit voltage and how do you know zero is zero? 42

3.2.5 Voltage drop testing example 43

3.2.6 Insulation testing 43

3.3 Oscilloscopes 44

3.3.1 Operation 44

3.3.2 High voltages and safety 45

3.3.3 AC–DC 45

3.3.4 Channels 45

3.3.5 Making connections 46

3.3.6 Non-invasive measurement 46

3.3.7 Wiggly lines 47

3.3.8 Example equipment 47

3.3.8.1 Snap-on Verdict 47

3.3.8.2 PicoScope 48

3.3.9 Waveform library 50

3.3.10 PicoDiagnostics 50

3.3.11 Pressure sensor 50

3.3.12 Noise and vibration 50

3.4 Diagnostic tools 53

3.4.1 On-board diagnostics 53

3.4.2 Diagnostic trouble codes 53

3.4.3 Example scanners 54

3.4.3.1 Basic DIY 54

3.4.3.2 VCDS 56

3.4.3.3 ArtiPad 56

3.4.3.4 How many scanners do you need? 57

3.4.4 Live data 57

3.4.5 Serial port communications 60

3.4.6 OBD2 signal protocols 60

3.4.7 Engine analysers 61

3.5 Emission testing 62

3.5.1 Introduction 62

3.5.2 Exhaust gas measurement 62

3.5.3 Exhaust analyser 62

3.5.4 Emission limits 63

viii Contents

3.6

Pressure testing

6

4

3.6.1

Introduction 64

3.6.2

Oscilloscope transducer

6

4

3.6.3

Pressure analysis

6

5

4

Sensors, actuators and oscilloscope diagnostics

7

3

4.1

Introduction 73

4.2

Sensors 73

4.2.1

Introduction and sensor diagnostics

7

3

4.2.2

Inductive sensors

7

3

4.2.2.1

Crankshaft and camshaft sensors

75

4.2.2.2

ABS speed sensor

75

4.2.2.3

Inductive distributor pick-up

7

7

4.2.3

Variable resistance

7

8

4.2.3.1

Throttle position potentiometer

7

9

4.2.3.2

Airflow meter – air vane

8

0

4.2.4

Hot wire airflow sensor

8

1

4.2.4.1

Airflow meter – hot wire

8

1

4.2.5

Thermistors 82

4.2.5.1

Coolant temperature sensor

8

3

4.2.6

Hall effect sensors

8

4

4.2.6.1

Hall effect distributor pick-up

8

4

4.2.6.2

ABS Hall sensor

8

4

4.2.6.3

Road speed sensor (Hall effect)

8

4

4.2.7

Piezo accelerometer

8

5

4.2.7.1

Knock sensor

8

5

4.2.8

Oxygen sensors

8

6

4.2.8.1

Oxygen sensor (Titania)

8

7

4.2.8.2

Oxygen sensor (Zirconia)

8

8

4.2.9

Pressure sensors

8

9

4.2.9.1

Strain gauges

8

9

4.2.9.2

Fuel pressure

8

9

4.2.9.3

Manifold absolute pressure

9

0

4.2.10

Variable capacitance

9

0

4.2.10.1

Oil quality sensor

9

2

4.2.11

Optical sensors

9

2

4.2.12

Dynamic position sensors

9

2

4.2.13

Rain sensor

9

3

4.3

Actuators 94

4.3.1

Introduction 94

4.3.2

Testing actuators

9

4

4.3.3

Motorised and solenoid actuators

9

5

4.3.3.1

Motors 95

4.3.3.2

Rotary idle speed control valve

9

5

4.3.3.3

Stepper motors

9

6

4.3.4

Solenoid actuators

9

7

4.3.4.1

Single-point injector

9

8

4.3.4.2

Multi-point injector

100

4.3.4.3

Common rail diesel injector

101

4.3.4.4

Idle speed control valve

102

Contents ix

4.3.4.5 Exhaust gas recirculation valve 102

4.3.4.6 Carbon canister and other valves 102

4.3.5 Thermal actuators 103

4.4 Engine waveforms 104

4.4.1 Ignition primary 104

4.4.2 Ignition secondary 104

4.4.3 Diesel glow plugs 107

4.4.4 Alternator waveform 107

4.4.5 Relative compression petrol 108

4.5 Communication networks 109

4.5.1 Introduction 109

4.5.2 CAN 109

4.5.3 LIN 110

4.5.4 FlexRay 112

4.5.5 Time-triggered CAN 112

4.5.6 Byteflight 112

4.5.7 Ethernet 113

4.6 Summary 115

Acknowledgement 115

5 On-board diagnostics 117

5.1 History 117

5.1.1 Introduction 117

5.1.2 Vehicle emissions and environmental health 117

5.1.3 History of the emissions control legislation 118

5.1.4 Introduction of vehicle emissions control strategies 119

5.2 What is on-board diagnostics? 119

5.2.1 OBD scenario example 120

5.2.2 Origins of OBD in the USA 121

5.2.3 P code composition 121

5.2.4 European on-board diagnostics and global adoption 122

5.2.5 Summary 122

5.3 Petrol/Gasoline on-board diagnostic monitors 122

5.3.1 Introduction 122

5.3.2 Legislative drivers 122

5.3.3 Component monitoring 123

5.3.4 Rationality testing 123

5.3.5 Circuit testing 123

5.3.6 Catalyst monitor 123

5.3.7 Evaporative system monitor 124

5.3.8 Fuel system monitoring 125

5.3.9 Exhaust gas recirculation monitor 127

5.3.10 Secondary air monitor 128

5.3.11 Monitors and readiness flags 128

5.4 Misfire detection 129

5.4.1 Misfire monitor 129

5.4.2 Crank speed fluctuation 131

5.4.3 Ionising current monitoring 131

5.4.4 Cylinder pressure sensing 132

5.4.5 Exhaust pressure analysis 133

x Contents

5.5 OBD overview 133

5.5.1 Introduction 133

5.5.2 OBD2 134

5.5.3 EOBD 135

5.5.4 Features and technology of current systems 136

5.5.4.1 MIL activation logic for detected malfunctions 136

5.5.4.2 MIL healing 136

5.5.4.3 Healing of the fault memory 137

5.5.4.4 Freeze frame 137

5.6 Driving cycles 137

5.6.1 Introduction 137

5.6.2 Europe 137

5.6.3 USA 138

5.6.4 Worldwide harmonized light vehicles test procedure 139

5.7 Future developments in diagnostic systems 140

5.7.1 OBD3 140

5.7.2 Diesel engines 141

5.7.3 Rate-based monitoring 141

5.7.4 Model-based development 141

5.7.5 OBD security 141

5.7.6 Summary 142

Acknowledgement 142

6 Engine systems 143

6.1 Introduction 143

6.2 Engine operation 143

6.2.1 Four-stroke cycle 143

6.2.2 Cylinder layouts 143

6.2.3 Camshaft drives 144

6.2.4 Valve mechanisms 145

6.2.5 Valve and ignition timing 145

6.3 Diagnostics – engines 147

6.3.1 Systematic testing example 147

6.3.2 Test equipment 147

6.3.2.1 Compression tester 147

6.3.2.2 Cylinder leakage tester 147

6.3.3 Test results 148

6.3.4 Engine fault diagnosis table 1 148

6.3.5 Engine fault diagnosis table 2 148

6.4 Fuel system 149

6.4.1 Introduction 149

6.4.2 Engine management 149

6.5 Diagnostics – basic fuel system 149

6.5.1 Systematic testing example 149

6.5.2 Test equipment 150

6.5.2.1 Exhaust gas analyser 150

6.5.2.2 Fuel pressure gauge 150

6.5.3 Test results 150

6.5.4 Fuel fault diagnosis table 1 151

6.5.5 Fuel fault diagnosis table 2 151

Contents xi

6.6 Ignition 151

6.6.1 Basics 151

6.6.2 Advance angle (timing) 152

6.6.3 Electronic ignition 152

6.6.4 Hall effect distributor 153

6.6.5 Inductive distributor 154

6.6.6 Current-limiting and closed-loop dwell 154

6.6.7 Programmed ignition/electronic spark advance 154

6.6.8 Distributorless ignition 156

6.6.9 Direct ignition 158

6.6.10 Spark plugs 159

6.7 Diagnostics – ignition system 161

6.7.1 Testing procedure 161

6.7.2 Ignition fault diagnosis table 161

6.7.3 Ignition components and testing 161

6.7.4 DIS diagnostics 163

6.7.5 Coil on plug (COP) diagnostics 163

6.7.6 Spark plugs 164

6.8 Emissions 166

6.8.1 Introduction 166

6.8.2 Exhaust gas recirculation (EGR) 166

6.8.3 Catalytic converters 167

6.9 Diagnostics – emissions 168

6.9.1 Testing procedure 168

6.9.2 Emissions fault diagnosis table 168

6.10 Fuel injection 168

6.10.1 Introduction 168

6.10.2 Injection systems 170

6.10.3 Fuel injection components 171

6.10.3.1 Airflow meter 171

6.10.3.2 Electronic control unit (ECU) 171

6.10.3.3 Fuel pump 171

6.10.3.4 Fuel filter 171

6.10.3.5 Lambda sensor 171

6.10.3.6 Temperature sensor 171

6.10.3.7 Fuel injectors 172

6.10.3.8 Idle or fast idle control actuator 172

6.10.3.9 Fuel pressure regulator 172

6.10.3.10 Throttle position switch 172

6.10.4 Fuel mixture calculation 172

6.11 Diagnostics – fuel injection systems 173

6.11.1 Testing procedure 173

6.11.2 Fuel injection fault diagnosis table 173

6.12 Diesel injection 173

6.12.1 Introduction 173

6.12.2 Electronic control of diesel injection 175

6.12.3 Common rail (CR) diesel systems 176

6.12.4 Diesel exhaust emissions 177

6.12.5 Catalytic converter diesel 177

6.12.6 Diesel particulate filters 178

6.12.7 Selective catalytic reduction 179

xii Contents

6.13 Diagnostics – diesel injection systems 180

6.13.1 Test equipment 180

6.13.1.1 Smoke meter 180

6.13.1.2 Injector tester 180

6.13.2 Diesel injection fault diagnosis table 180

6.13.3 Diesel engine smoke 180

6.13.3.1 White or grey smoke 181

6.13.3.2 Blue smoke 181

6.13.3.3 Black smoke 181

6.13.4 Glow plug circuit 181

6.13.5 Diesel systems 182

6.14 Engine management 182

6.14.1 Introduction 182

6.14.2 Closed-loop lambda control 183

6.14.3 Engine management operation 184

6.14.4 Gasoline direct injection (GDI) 187

6.14.5 ECU calibration 189

6.15 Diagnostics – combined ignition and fuel systems 190

6.15.1 Testing procedure 190

6.15.2 Combined ignition and fuel control fault diagnosis table 192

6.15.3 Fuel pump testing 193

6.15.4 Injector testing 193

6.15.5 ECU fuel trim diagnostics 193

6.16 Air supply and exhaust systems 197

6.16.1 Exhaust system 197

6.16.2 Catalytic converters 198

6.16.3 Air supply system 199

6.17 Diagnostics – exhaust and air supply 199

6.17.1 Systematic testing 199

6.17.2 Test results 199

6.17.3 Exhaust and air supply fault diagnosis table 1 200

6.17.4 Exhaust fault diagnosis table 2 200

6.18 Cooling 200

6.18.1 Air-cooled system 200

6.18.2 Water-cooled system 200

6.18.3 Sealed and semi-sealed systems 201

6.18.4 Thermal management systems 202

6.19 Diagnostics – cooling 202

6.19.1 Systematic testing 202

6.19.2 Test equipment 202

6.19.2.1 Cooling system pressure tester 202

6.19.2.2 Antifreeze tester 203

6.19.2.3 Temperature meter/thermometer 203

6.19.3 Test results 203

6.19.4 Cooling fault diagnosis table 1 203

6.19.5 Cooling fault diagnosis table 2 203

6.20 Lubrication 204

6.20.1 Lubrication system 204

6.20.2 Oil filters 204

Contents xiii

6.20.3 Oil pumps 204

6.20.4 Crankcase ventilation engine breather systems 205

6.21 Diagnostics – lubrication 206

6.21.1 Systematic testing 206

6.21.2 Test equipment 206

6.21.2.1 Oil pressure test gauge 206

6.21.2.2 Vacuum gauge 206

6.21.3 Test results 206

6.21.4 Lubrication fault diagnosis table 1 207

6.21.5 Lubrication fault diagnosis table 2 207

6.22 Batteries 207

6.22.1 Safety 207

6.22.2 Lead-acid batteries 207

6.22.3 Battery rating 208

6.23 Diagnostics – batteries 208

6.23.1 Servicing batteries 208

6.23.2 Maintenance-free 208

6.23.3 Charging 209

6.23.3.1 Smart chargers 209

6.23.4 Battery faults 210

6.23.5 Testing batteries 210

6.23.6 Battery diagnostics 211

6.24 Starting 215

6.24.1 Starter circuit 215

6.24.2 Pre-engaged starters 215

6.24.3 Keyless starting system 217

6.25 Diagnostics – starting 218

6.25.1 Circuit testing procedure 218

6.25.2 Starting fault diagnosis table 220

6.26 Charging 220

6.26.1 Introduction 220

6.26.2 Basic principles 221

6.26.3 Rectification of AC to DC 221

6.26.4 Regulation of output voltage 222

6.26.5 Basic charging circuits 224

6.26.6 Smart charging 224

6.27 Diagnostics – charging 225

6.27.1 Testing procedure 225

6.27.2 Charging fault diagnosis table 226

7 Chassis systems 227

7.1 Brakes 227

7.1.1 Introduction 227

7.1.2 Principle of hydraulic braking 227

7.1.3 Disc and drum brake systems 228

7.1.4 Brake adjustments 229

7.1.5 Servo-assisted braking 229

7.1.6 Brake fluid 230

xiv Contents

7.2 Diagnostics – brakes 230

7.2.1 Systematic testing 230

7.2.2 Test equipment 230

7.2.2.1 Brake fluid tester 230

7.2.2.2 Brake roller test 230

7.2.3 Dial gauge 231

7.2.4 Test results 231

7.2.5 Brakes fault diagnosis table 1 232

7.2.6 Brakes fault diagnosis table 2 232

7.2.7 Brake hydraulic faults 233

7.2.8 Electronic brake system bleeding 233

7.3 Antilock brakes 233

7.3.1 Introduction 233

7.3.2 Requirements of ABS 233

7.3.3 General system description 234

7.3.4 ABS components 234

7.3.4.1 Wheel speed sensors 234

7.3.4.2 Electronic control unit 235

7.3.4.3 Hydraulic modulator 235

7.4 Diagnostics – antilock brakes 236

7.4.1 Systematic testing procedure 236

7.4.2 Antilock brakes fault diagnosis table 236

7.4.3 Bleeding antilock brakes 236

7.5 Traction control 236

7.5.1 Introduction 236

7.5.2 Control functions 236

7.5.3 System operation 236

7.6 Diagnostics – traction control 238

7.6.1 Systematic testing 238

7.6.2 Traction control fault diagnosis table 238

7.7 Steering and tyres 240

7.7.1 Construction of a tubeless radial tyre 240

7.7.2 Steering box and rack 240

7.7.3 Power-assisted steering 241

7.7.4 Steering characteristics 241

7.7.5 Camber 242

7.7.6 Castor 243

7.7.7 Swivel axis inclination 244

7.7.8 Tracking 245

7.7.9 Scrub radius 245

7.8 Diagnostics – steering and tyres 246

7.8.1 Systematic testing 246

7.8.2 Test equipment 246

7.8.2.1 Tyre pressure gauge and tread depth gauge 246

7.8.2.2 Tracking gauges 246

7.8.2.3 Wheel balancer 246

7.8.3 Four-wheel alignment 246

7.8.4 Test results 247

7.8.5 Tyres fault diagnosis table 247

7.8.6 Tyre inflation pressures 247

7.8.7 Steering fault diagnosis 248