Automobile electrical and electronic systems

Automobile

Electrical and

Electronic Systems

Fourth Edition

(Automotive Technology: Vehicle Maintenance and Repair)

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Automobile

Electrical and

Electronic

Systems

Fourth Edition

Automotive Technology:

Vehicle Maintenance and Repair

Tom Denton BA FIMI MSAE

MIRTE Cert Ed

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Fourth Edition fi rst published in 2012

by Routledge

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

Simultaneously published in the USA and Canada

by Routledge

711 Third Avenue, New York, NY 10017

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

© 1995, 2000, 2004, 2012 Tom Denton

The right of Tom Denton to be identifi ed 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 identifi cation and explanation without intent to infringe.

First edition published 1995 by Arnold, a member of Hodder Headline plc.

Third edition published 2004 by Elsevier

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

[CIP data]

ISBN: 978-0-08-096942-8 (pbk)

ISBN: 978-0-080-96943-5 (ebk)

Typeset in Helvetica

by Refi neCatch Limited, Bungay, Suffolk

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Contents

Preface xxiii

Acknowledgements xxv

Glossary of abbreviations and acronyms xxvii

Chapter 1 Development of the automobile electrical system 1

1.1 A short history 1

1.1.1 Where did it all begin? 1

1.1.2 A chronological history 4

1.2 Where next? 12

1.2.1 Current developments 12

1.2.2 Auto-electrical systems in the next millennium 12

1.2.3 Automobile systems in the next millennium –

‘The modern driver’ 13

1.2.4 An eye on the future 15

1.2.5 The death of the car – Energise? 17

Chapter 2 Electrical and electronic principles 19

2.1 Safe working practices 19

2.1.1 Introduction 19

2.1.2 Risk assessment and reduction 19

2.2 Basic electrical principles 19

2.2.1 Introduction 19

2.2.2 Electron fl ow and conventional fl ow 20

2.2.3 Effects of current fl ow 21

2.2.4 Fundamental quantities 22

2.2.5 Describing electrical circuits 22

2.2.6 Conductors, insulators and semiconductors 23

2.2.7 Factors affecting the resistance of a conductor 23

2.2.8 Resistors and circuit networks 23

2.2.9 Magnetism and electromagnetism 25

2.2.10 Electromagnetic induction 26

2.2.11 Mutual induction 26

2.2.12 Defi nitions and laws 26

2.3 Electronic components and circuits 29

2.3.1 Introduction 29

2.3.2 Components 29

2.3.3 Integrated circuits 33

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vi Contents

2.3.4 Amplifi ers 34

2.3.5 Bridge circuits 37

2.3.6 Schmitt trigger 37

2.3.7 Timers 38

2.3.8 Filters 38

2.3.9 Darlington pair 40

2.3.10 Stepper motor driver 40

2.3.11 Digital to analogue conversion 41

2.3.12 Analogue to digital conversion 42

2.4 Digital electronics 43

2.4.1 Introduction to digital circuits 43

2.4.2 Logic gates 43

2.4.3 Combinational logic 44

2.4.4 Sequential logic 45

2.4.5 Timers and counters 46

2.4.6 Memory circuits 47

2.4.7 Clock or astable circuits 49

2.5 Microprocessor systems 49

2.5.1 Introduction 49

2.5.2 Ports 49

2.5.3 Central processing unit (CPU) 50

2.5.4 Memory 50

2.5.5 Buses 50

2.5.6 Fetch–execute sequence 51

2.5.7 A typical microprocessor 51

2.5.8 Microcontrollers 53

2.5.9 Testing microcontroller systems 54

2.5.10 Programming 54

2.6 Measurement 55

2.6.1 What is measurement 55

2.6.2 A measurement system 56

2.6.3 Sources of error in measurement 56

2.7 Sensors 58

2.7.1 Thermistors 58

2.7.2 Thermocouples 59

2.7.3 Inductive sensors 60

2.7.4 Hall Effect 61

2.7.5 Strain gauges 62

2.7.6 Variable capacitance 63

2.7.7 Variable resistance 64

2.7.8 Accelerometer (knock sensors) 66

2.7.9 Linear variable differential transformer (LVDT) 68

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Contents vii

2.7.10 Hot wire air fl ow sensor 69

2.7.11 Thin fi lm air fl ow sensor 70

2.7.12 Vortex fl ow sensor 70

2.7.13 Pitot tube 71

2.7.14 Turbine fl uid fl ow sensor 71

2.7.15 Optical sensors 72

2.7.16 Oxygen sensors 72

2.7.17 Light sensors 73

2.7.18 Thick-fi lm air temperature sensor 74

2.7.19 Methanol sensor 74

2.7.20 Rain sensor 74

2.7.21 Oil sensor 75

2.7.22 Dynamic vehicle position sensors 75

2.7.23 Summary 76

2.8 Actuators 77

2.8.1 Introduction 77

2.8.2 Solenoid actuators 77

2.8.3 EGR valve 78

2.8.4 Motorized actuators 79

2.8.5 Stepper motors 80

2.8.6 Synchronous motors 84

2.8.7 Thermal actuators 84

2.9 Testing electronic components, sensors and actuators 84

2.9.1 Introduction 84

2.9.2 Testing sensors 85

2.9.3 Testing actuators 86

Chapter 3 Tools and equipment 87

3.1 Basic equipment 87

3.1.1 Introduction 87

3.1.2 Basic hand tools 87

3.1.3 Accuracy of test equipment 88

3.1.4 Multimeters 89

3.1.5 Logic probe 91

3.2 Oscilloscopes 93

3.2.1 Introduction 93

3.2.2 Waveforms 94

3.3 Scanners/Fault code readers and analysers 95

3.3.1 On-board diagnostics introduction 95

3.3.2 Serial port communications 95

3.3.3 OBD2 signal protocols 96

3.3.4 AutoTap OBD scanner 97

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viii Contents

3.3.5 Bosch KTS diagnostic equipment 99

3.3.6 Engine analysers 101

3.4 Emission testing 103

3.4.1 Introduction 103

3.4.2 Exhaust gas measurement 103

3.4.3 Exhaust analyser 104

3.4.4 Emission limits 106

3.5 Pressure testing 108

3.5.1 Introduction 108

3.5.2 Automotive pressure oscilloscope transducer 109

3.5.3 Breakout boxes 110

3.6 Diagnostic procedures 110

3.6.1 Introduction 110

3.6.2 The ‘theory’ of diagnostics 111

Chapter 4 Electrical systems and circuits 113

4.1 The systems approach 113

4.1.1 What is a system? 113

4.1.2 Vehicle systems 113

4.1.3 Open loop systems 114

4.1.4 Closed loop systems 114

4.1.5 Summary 115

4.2 Electrical wiring, terminals and switching 115

4.2.1 Cables 115

4.2.2 Colour codes and terminal designations 116

4.2.3 Harness design 119

4.2.4 Printed circuits 122

4.2.5 Fuses and circuit breakers 123

4.2.6 Terminations 125

4.2.7 Switches 127

4.3 Multiplexing 129

4.3.1 Limits of the conventional wiring system 129

4.3.2 Multiplex data bus 131

4.3.3 Overview 131

4.3.4 Controller Area Network (CAN) 133

4.3.5 CAN data signal 135

4.3.6 Local Interconnect Network (LIN) 139

4.3.7 FlexRay 141

4.4 Media oriented systems transport (MOST) 144

4.4.1 Introduction 144

4.4.2 MOST network 144

4.4.3 Protocol 145

Contents ix

4.4.4 MOST applications 146

4.4.5 Consumer device gateway 146

4.4.6 Summary 146

4.5 Automotive Ethernet 147

4.5.1 Introduction 147

4.5.2 Overview 147

4.6 Circuit diagrams and symbols 148

4.6.1 Symbols 148

4.6.2 Conventional circuit diagrams 148

4.6.3 Layout or wiring diagrams 148

4.6.4 Terminal diagrams 148

4.6.5 Current fl ow diagrams 150

4.7 Electromagnetic compatibility 150

4.7.1 Introduction 150

4.7.2 EMC problems 150

4.8 Central electrical control 153

4.8.1 Overview 153

4.8.2 Ford generic electronic module (GEM) 155

4.8.3 Communication between modules 161

4.8.4 Summary 166

4.9 Connected cars 166

4.9.1 Introduction 166

4.9.2 Smart cars and traffi c systems 166

4.9.3 Wi-Fi cars 169

4.9.4 Bluetooth 170

4.9.5 Applications (apps) 171

4.9.6 Vision enhancement 172

4.9.7 Self-help 173

4.9.8 Big brother 174

4.9.9 When computers go wrong 174

4.9.10 Summary 175

Chapter 5 Batteries 177

5.1 Vehicle batteries 177

5.1.1 Requirements of the vehicle battery 177

5.1.2 Choosing the correct battery 178

5.1.3 Positioning the vehicle battery 178

5.2 Lead-acid batteries 179

5.2.1 Construction 179

5.2.2 Battery rating 180

5.3 Maintenance, charging and testing batteries 182

5.3.1 Maintenance 182

5.3.2 Charging the lead-acid battery 182

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5.3.3 Servicing batteries 185

5.3.4 Battery faults 185

5.3.5 Testing batteries 185

5.3.6 Safety 189

5.4 Advanced battery technology 189

5.4.1 Electrochemistry 189

5.4.2 Electrolytic conduction 190

5.4.3 Ohm’s Law and electrolytic resistance 190

5.4.4 Electrochemical action of the

lead-acid battery 191

5.4.5 Characteristics 193

5.4.6 Peukert’s Law 194

5.5 Developments in electrical storage 194

5.5.1 Lead-acid 194

5.5.2 Alkaline 195

5.5.3 ZEBRA 197

5.5.4 Sodium sulphur 197

5.5.5 Swing 197

5.5.6 Fuel cells 198

5.5.7 Super-capacitors 201

5.5.8 Summary 201

Chapter 6 Charging 203

6.1 Requirements of the charging system 203

6.1.1 Introduction 203

6.1.2 Basic operating principles 203

6.1.3 Vehicle electrical loads 204

6.2 Charging system principles 206

6.2.1 Basic principles 206

6.2.2 Charging voltages 206

6.2.3 Charging circuits 207

6.2.4 Generation of electricity 207

6.2.5 Rectifi cation of AC to DC 209

6.2.6 Regulation of output voltage 212

6.3 Alternators 216

6.3.1 Bosch compact alternator 216

6.3.2 Effi cient alternators 218

6.3.3 Water-cooled alternators 219

6.3.4 Denso high-output alternators 220

6.3.5 Charging system testing procedure 220

6.4 Smart charging 221

6.4.1 Introduction and closed loop regulation 221

6.4.2 Open loop regulation 223

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Contents xi

6.4.3 Engine performance 223

6.4.4 Fault conditions 225

6.4.5 Summary 225

6.5 Advanced charging system technology 225

6.5.1 Charging system – problems and solutions 225

6.5.2 Charge balance calculation 228

6.5.3 Alternator characteristics 229

6.5.4 Mechanical and external considerations 230

Chapter 7 Starting 231

7.1 Requirements of the starting system 231

7.1.1 Engine starting requirements 231

7.1.2 Starting system design 232

7.1.3 Choosing a starter motor 234

7.2 Starter motors and circuits 236

7.2.1 Starting system circuits 236

7.2.2 Example circuits 236

7.2.3 Starter circuit testing 239

7.2.4 Principle of operation 240

7.2.5 DC motor characteristics 243

7.3 Types of starter motor 244

7.3.1 Inertia starters 244

7.3.2 Pre-engaged starters 245

7.3.3 Permanent magnet starters 247

7.3.4 Integrated starters 249

7.3.5 Electronic starter control 249

7.3.6 Starter installation 249

7.3.7 Belt-driven starter-generator 250

7.3.8 Summary 251

7.4 Advanced starting system technology 251

7.4.1 Speed, torque and power 251

7.4.2 Effi ciency 253

Chapter 8 Ignition 255

8.1 Ignition system fundamentals 255

8.1.1 Functional requirements 255

8.1.2 Generation of high tension 255

8.1.3 Advance angle (timing) 256

8.1.4 Fuel consumption and exhaust emissions 257

8.1.5 Contact breaker ignition 257

8.1.6 Plug leads 258

8.1.7 Ignition coil cores 258

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8.2 Electronic ignition 260

8.2.1 Introduction 260

8.2.2 Constant dwell systems 260

8.2.3 Constant energy systems 261

8.2.4 Hall Effect pulse generator 261

8.2.5 Inductive pulse generator 262

8.2.6 Other pulse generators 262

8.2.7 Dwell angle control (open loop) 264

8.2.8 Current limiting and closed loop dwell 265

8.2.9 Capacitor discharge ignition 266

8.3 Electronic spark advance 267

8.3.1 Overview 267

8.3.2 Sensors and input information 268

8.3.3 Electronic control unit 269

8.4 Distributorless ignition 272

8.4.1 Principle of operation 272

8.4.2 System components 273

8.5 Coil on plug (COP) ignition 273

8.5.1 General description 273

8.5.2 Control of ignition 275

8.6 Spark plugs 275

8.6.1 Functional requirements 275

8.6.2 Construction 276

8.6.3 Heat range 277

8.6.4 Electrode materials 278

8.6.5 Electrode gap 279

8.6.6 V-grooved spark plug 279

8.6.7 Choosing the correct plug 280

8.6.8 Spark plugs development 281

8.7 Summary 281

8.7.1 Overview 281

8.7.2 Testing procedure 283

8.8 Advanced ignition technology 285

8.8.1 Ignition coil performance 285

Chapter 9 Fuel control 287

9.1 Combustion 287

9.1.1 Introduction 287

9.1.2 Spark ignition engine combustion process 287

9.1.3 Range and rate of burning 289

9.1.4 Detonation 289

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Contents xiii

9.1.5 Pre-ignition 291

9.1.6 Combustion chamber 292

9.1.7 Stratifi cation of cylinder charge 292

9.1.8 Mixture strength and performance 293

9.1.9 Compression ignition (CI) engines 293

9.1.10 Combustion chamber design – diesel engine 296

9.1.11 Summary of combustion 296

9.2 Engine fuelling and exhaust emissions 297

9.2.1 Operating conditions 297

9.2.2 Exhaust emissions 297

9.2.3 Other sources of emissions 298

9.2.4 Leaded and unleaded fuel 299

9.3 Emissions and driving cycles 300

9.3.1 Exhaust emission regulations 300

9.3.2 Test cycles 301

9.4 Electronic control of carburation 304

9.4.1 Basic carburation 304

9.4.2 Areas of control 305

9.5 Fuel injection 306

9.5.1 Advantages of fuel injection 306

9.5.2 System overview 306

9.5.3 Components of a fuel injection system 310

9.5.4 Bosch ‘L’ Jetronic – Variations 314

9.5.5 Bosch Mono Jetronic – single point injection 315

9.5.6 Sequential multipoint injection 317

9.5.7 Lean burn technology 318

9.5.8 Double fuel injectors 320

9.6 Diesel fuel injection 321

9.6.1 Introduction 321

9.6.2 Injection overview 326

9.6.3 Diesel exhaust emissions 327

9.6.4 Electronic control of diesel injection 328

9.6.5 Rotary Pump System 329

9.6.6 Common rail system 332

9.6.7 Electronic unit injection (EUI) – diesel fuel 337

9.6.8 Diesel lambda sensor 339

9.6.9 Exhaust emission treatments 340

9.7 Summary 341

9.7.1 Overview 341

9.7.2 Diagnosing fuel control systems 342

9.8 Advanced fuel control technology 343

9.8.1 Air–fuel ratio calculations 343

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Chapter 10 Engine management 345

10.1 Combined ignition and fuel introduction 345

10.1.1 Introduction 345

10.1.2 Variable inlet tract 346

10.1.3 Combustion fl ame and pressure sensing 346

10.1.4 Wide range lambda sensors 347

10.1.5 Injectors with air shrouding 347

10.2 Exhaust emission control 347

10.2.1 Engine design 347

10.2.2 Combustion chamber design 347

10.2.3 Compression ratio 348

10.2.4 Valve timing 348

10.2.5 Manifold designs 348

10.2.6 Charge stratifi cation 348

10.2.7 Warm up time 348

10.2.8 Exhaust gas recirculation 349

10.2.9 Ignition system 350

10.2.10 Thermal after-burning 350

10.2.11 Catalytic converters 350

10.2.12 Closed loop lambda control 353

10.3 Engine management systems 354

10.3.1 Motronic M3 354

10.3.2 DI-Motronic 365

10.3.3 ME-Motronic principles 370

10.4 Other aspects of engine management 371

10.4.1 Introduction 371

10.4.2 Variable valve timing 371

10.4.3 Lean burn engines 374

10.4.4 Two-stroke engines 374

10.4.5 Combustion control system 375

10.4.6 Active cooling 377

10.4.7 Engine trends – spark ignition 379

10.4.8 Transonic combustion 380

10.4.9 Formula 1 engine technology 381

10.4.10 Diagnosing engine management systems 382

10.5 Advanced engine management technology 385

10.5.1 Speed density and fuel calculations 385

10.5.2 Ignition timing calculation 386

10.5.3 Dwell calculation 388

10.5.4 Injection duration calculation 388

10.5.5 Developing and testing software 389

10.5.6 Simulation program 391

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