Automotive mechanical and electrical systems

Automobile Mechanical and

Electrical Systems

The second edition of Automobile Mechanical and Electrical Systems concentrates on core technologies

to provide the essential information required to understand how different vehicle systems work. It gives a

complete overview of the components and workings of a vehicle from the engine through to the chassis

and electronics. It also explains the necessary tools and equipment needed in effective car maintenance

and repair, and relevant safety procedures are included throughout.

Designed to make learning easier, this book contains:

Photographs, fl ow charts and quick reference tables

Detailed diagrams and clear descriptions that simplify the more complicated topics and aid revision

Useful features throughout, including defi nitions, key facts and ‘safety fi rst’ considerations.

In full colour and with support materials from the author’s website (www.automotive-technology.org), this

is the guide no student enrolled on an automotive maintenance and repair course should be without.

Tom Denton is a Fellow of the Institute of the Motor Industry and a Member of the Institute of Road

Transport Engineers and of the Society of Automotive Engineers. He has written over 20 textbooks, along

with support materials, and world-leading eLearning courses.

Second Edition

Tom Denton

Automobile Mechanical and

Electrical Systems

Second edition published 2018

by Routledge

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

and by Routledge

711 Third Avenue, New York, NY 10017

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

© 2018 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 published by Butterworth-Heinemann 2011

First edition published by Routledge 2014

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

A catalog record for this book has been requested

ISBN: 978-1-138-50058-7 (hbk)

ISBN: 978-0-415-72578-1 (pbk)

ISBN: 978-1-315-85663-6 (ebk)

Typeset in Univers

by Apex CoVantage, LLC

v

Preface viii

About the author ix

Acknowledgements x

1 Overview and introduction 1

1.1 Vehicle categories 1

1.1.1 Layouts 1

1.1.2 Types and sizes 2

1.1.3 Body design 2

1.1.4 Chassis type and body panels 2

1.1.5 Main systems 5

1.1.6 Summary 6

1.2 The motor industry 6

1.2.1 Introduction 6

1.2.2 Types of motor vehicle companies 6

1.2.3 Company structure 10

1.2.4 Role of a franchised dealer 10

1.2.5 Reception and booking systems 10

1.2.6 Parts department 10

1.2.7 Estimating costs and times 11

1.2.8 Job cards and systems 11

1.2.9 Invoicing 12

1.2.10 Warranties 12

1.2.11 Computerized workshop system 12

1.3 Working safely 15

1.3.1 Introduction 15

1.3.2 The key UK regulations and laws 16

1.3.3 Health and safety law: what you

need to know 16

1.3.4 Personal protective

equipment (PPE) 18

1.3.5 Identifying and reducing hazards 20

1.3.6 Moving loads 21

1.3.7 Vehicle safety 24

1.3.8 Safety procedures 24

1.3.9 Fire 24

1.3.10 Clean working environment 27

1.3.11 Signage 28

1.3.12 Environmental protection 29

1.4 Basic science, materials, mathematics

and mechanics 29

1.4.1 Introduction 29

1.4.2 Units 31

1.4.3 Velocity and acceleration 32

1.4.4 Friction 32

1.4.5 Pressure 32

1.4.6 Centre of gravity or centre

of mass 32

1.4.7 Oscillation 33

1.4.8 Energy, work and power 33

1.4.9 Force and torque 34

1.4.10 Mass, weight and force 34

1.4.11 Volume and density 34

1.4.12 Heat and temperature 35

1.4.13 Percentages 35

1.4.14 Fractions 36

1.4.15 Ratios 36

1.4.16 Areas 36

1.4.17 Volumes 36

1.4.18 Indices 36

1.4.19 Drawings 37

1.4.20 Mechanical machines 37

1.4.21 Gears 38

1.4.22 Hydraulics 39

1.4.23 Materials and properties 39

1.5 Tools and equipment 40

1.5.1 Hand tools 40

1.5.2 Test equipment 41

1.5.3 Workshop equipment 42

1.6 Workshop bench skills 42

1.6.1 Introduction 42

1.6.2 Fitting and machining 43

1.6.3 Filing 44

1.6.4 Drilling 44

1.6.5 Cutting 45

1.6.6 Thread cutting 45

1.6.7 Joining 46

1.6.8 Nuts and bolts 47

1.6.9 Adhesives 48

1.6.10 Soldering 49

1.6.11 Brazing 49

1.6.12 Welding 49

1.6.13 Shrinking 50

1.6.14 Compression fi tting 50

1.6.15 Riveting 50

Contents

Contents

vi

1.6.16 Gaskets 50

1.6.17 Sealants 51

1.6.18 Oil seals 51

1.7 Servicing and inspections 51

1.7.1 Introduction 51

1.7.2 Rules and regulations 52

1.7.3 Service sheets 52

1.7.4 Road test 53

1.7.5 Effects of incorrect adjustments 53

1.7.6 Maintenance and inspections 56

1.7.7 Information sources 56

2 Engine systems 59

2.1 Engine mechanical 59

2.1.1 Introduction and operating cycles 59

2.1.2 Engine operating details 66

2.1.3 Engine components 78

2.2 Engine lubrication 95

2.2.1 Friction and lubrication 95

2.2.2 Methods of lubrication 96

2.2.3 Lubrication system 97

2.2.4 Oil fi lters 99

2.2.5 Oil pumps 100

2.2.6 Standards 101

2.3 Engine cooling 103

2.3.1 Introduction 103

2.3.2 System operation 104

2.3.3 Interior heater 113

2.4 Air supply, exhaust and emissions 114

2.4.1 Air pollution and engine

combustion 114

2.4.2 Reducing pollution 115

2.4.3 Air supply system 117

2.4.4 Exhaust systems 119

2.4.5 Catalyst systems 121

2.4.6 Emission control systems 122

2.4.7 Turbocharging and supercharging 125

2.5 Fuel systems 128

2.5.1 Introduction 128

2.5.2 Petrol fuel injection systems 132

2.5.3 Diesel fuel injection systems 147

2.6 Ignition systems 158

2.6.1 Ignition overview 158

2.6.2 Electronic ignition 161

2.6.3 Distributorless ignition

system (DIS) 162

2.6.4 Coil on plug (COP) direct ignition

system 164

2.6.5 Spark plugs 165

2.7 Electric and hybrid cars 166

2.7.1 Types of electric vehicle 166

2.7.2 The EV experience 167

2.8 Engine systems: new developments

and updates 168

2.8.1 Spark plug electrode designs 168

2.8.2 V6 diesel with electric

turbocharging 169

2.8.3 Water injection 170

2.8.4 Cylinder deactivation 171

2.8.5 Dynamic skip fi re 172

2.8.6 Diesel particulate fi lters 172

2.8.7 Oil fi lter modules 174

2.8.8 Miller cycle 175

2.8.9 Cooled EGR 175

3 Electrical systems 177

3.1 Electrical and electronic principles 177

3.1.1 Electrical fundamentals 177

3.1.2 Electrical components and

circuits 181

3.1.3 Electronic components 188

3.2 Engine electrical 190

3.2.1 Batteries 190

3.2.2 Starting system 196

3.2.3 Charging system 200

3.3 Lighting and indicators 204

3.3.1 Lighting systems 204

3.3.2 Stoplights and reverse lights 207

3.3.3 Interior lighting 208

3.3.4 Lighting circuits 208

3.3.5 Indicators and hazard lights 210

3.4 Body electrical and electronic systems 212

3.4.1 Washers and wipers 212

3.4.2 Horns 215

3.4.3 Obstacle avoidance 216

3.4.4 Cruise control 216

3.4.5 Seats, mirrors, sunroofs, locking

and windows 217

3.4.6 Screen heating 222

3.4.7 Security systems 222

3.4.8 Safety systems 223

3.5 Monitoring and instrumentation 226

3.5.1 Sensors 226

3.5.2 Gauges 228

3.5.3 Global Positioning System (GPS) 230

3.6 Air conditioning 233

3.6.1 Air conditioning fundamentals 233

3.6.2 Air conditioning components 235

3.7 Electrical systems: new developments

and updates 237

3.7.1 Touchscreen with haptic

feedback 237

3.7.2 Navigation and the new NDS

data standard 237

3.7.3 Battery diagnostics 239

3.7.4 Alternator developments 240

3.7.5 Electronic starter motor control

and stop-start system 242

Contents

vii

3.7.6 Advanced driver assistance

systems (ADAS) 243

3.7.7 BMW laser headlamps 244

4 Chassis systems 245

4.1 Suspension 245

4.1.1 Overview of suspension 245

4.1.2 Dampers/shock absorbers 253

4.1.3 Suspension layouts 255

4.1.4 Active suspension 258

4.2 Steering 260

4.2.1 Introduction to steering 260

4.2.2 Steering racks and boxes 262

4.2.3 Steering geometry 267

4.2.4 Power steering 273

4.3 Brakes 276

4.3.1 Disc, drum and parking

brakes 276

4.3.2 Hydraulic components 282

4.3.3 Brake servo operation 284

4.3.4 Braking force control 285

4.3.5 Anti-lock brake systems 286

4.3.6 Traction control 290

4.4 Wheels and tyres 291

4.4.1 Wheels and rims 291

4.4.2 Tyre basics 295

4.4.3 Tread patterns 298

4.4.4 Tyre pressure monitoring 299

4.4.5 Tyre pressure monitoring and

the law in Europe 300

4.4.6 Spare wheels and extended

mobility 301

4.5 Chassis systems: new developments

and updates 302

4.5.1 Electric power steering 302

4.5.2 Electronic parking brake 304

4.5.3 Carbon ceramic brakes 305

4.5.4 Antilock braking system

(ABS) update 306

4.5.5 Predictive active ride control 308

5 Transmission systems 309

5.1 Manual transmission clutch 309

5.1.1 Clutch operation 309

5.1.2 Types of clutch 311

5.2 Manual transmission gearbox 314

5.2.1 Gearbox operation 314

5.2.2 Gear change mechanisms 316

5.2.3 Gears and components 318

5.3 Automatic transmission 321

5.3.1 Introduction and torque

converter 321

5.3.2 Automatic transmission

components 325

5.3.3 Constantly variable transmission 331

5.3.4 Direct shift gearbox 332

5.4 Transmission driveline 336

5.4.1 Propshafts and driveshafts 336

5.4.2 Wheel bearings 339

5.4.3 Four-wheel drive 342

5.5 Final drive and differential 344

5.5.1 Final drive 344

5.5.2 Differential 346

5.6 Transmission systems: new

developments and updates 349

5.6.1 Electronic clutch 349

5.6.2 Automatic transmission with

nine speeds 350

6 Automotive Technology Academy 351

6.1 Introduction 351

6.2 Resources 352

Index 353

viii

Preface

One of the things that I fi nd most interesting about automotive technology is how it advances and changes. It is

also interesting that ideas from many years ago often return to favour. In this book, I have therefore concentrated

on core technologies, in other words how things work, rather than giving details about specifi c vehicles or

manufacturers. However, I have included some examples of existing and upcoming technologies as a guide to

how things are changing.

This book is the fi rst in the ‘Automotive Technology: Vehicle Maintenance and Repair’ series:

Automobile Mechanical and Electrical Systems

Automobile Electrical and Electronic Systems

Automobile Advanced Fault Diagnosis

Electric and Hybrid Vehicles

Alternative Fuel Vehicles.

This book concentrates on essential knowledge and will cover everything you need to get started with your

studies, no matter what qualifi cation (if any) you are working towards. When you want more detailed information,

you can move on to the other books. I hope you fi nd the content useful and informative.

Comments, suggestions and feedback are always welcome at my website:

www.automotive-technology.org

On this site, you will also fi nd lots of free online resources to help with your studies. Check out Chapter 6 for

more information about the amazing resources to go with this and my other books. These resources work with

the book, and are ideal for self-study or for teachers helping others to learn.

Good luck and I hope you fi nd automotive technology as interesting as I still do.

ix

About the author

Tom Denton has been researching and writing best-selling

automotive textbooks for over 25 years. His published work is

endorsed by all leading professional organizations and used by

automotive students across the world. He has taught college

students at all levels, and always helped them achieve the best

results. Tom was also a Staff Tutor and is currently an Associate

Lecturer for the Open University.

His post graduate education in all aspects of technology and

education, as well as many years of practical experience, has 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, 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 over 20 textbooks, Tom has created amazing support materials and eLearning courses.

x

Acknowledgements

Over the years many people have helped in the production of my books. I am therefore very grateful to the

following companies who provided information and/or permission to reproduce photographs and/or diagrams:

AA

AC Delco

ACEA

Alpine Audio Systems

Audi

Autologic Data Systems

BMW UK

Brembo brakes

C&K Components

Citroën UK

Clarion Car Audio

Continental

CuiCAR

Delphi Media

Eberspaecher

Fluke Instruments UK

Flybrid systems

Ford Motor Company

FreeScale Electronics

General Motors

GenRad

haloIPT (Qualcomm)

Hella

HEVT

Honda

Hyundai

Institute of the Motor Industry

Jaguar Cars

Kavlico

Loctite

Lucas UK

LucasVarity

Mahle

Mazda

McLaren Electronic Systems

Mennekes

Mercedes

Mitsubishi

Most Corporation

NGK Plugs

Nissan

Oak Ridge National Labs

Peugeot

Philips

PicoTech/PicoScope

Pierburg

Pioneer Radio

Porsche

Renesas

Robert Bosch Gmbh/Media

Rolec

Rover Cars

Saab Media

Scandmec

SMSC

Snap-on Tools

Society of Motor Manufacturers

and Traders (SMMT)

Sofanou

Sun Electric

T&M Auto-Electrical

Tesla Motors

Thrust SSC Land Speed Team

Toyota

Tracker

Tula

Unipart Group

Valeo

Vauxhall

VDO Instruments

Volkswagen

Volvo Media

Wikimedia

ZF Servomatic

If I have used any information, or mentioned a company name that is not listed here, please accept my apologies

and let me know so it can be rectifi ed as soon as possible.

CHAPTER 1

Automobile Mechanical and Electrical Systems. 978-0-415-72578-1 © 2018 Tom Denton.

Published by Taylor & Francis. All rights reserved.

1

1.1 Vehicle categories

1.1.1 Layouts

This section is a general introduction to the car as a

whole. Over the years many unusual designs have

been tried, some with more success than others. The

most common is, of course, a rectangular vehicle with

a wheel at each corner! To take this rather simple idea

further, we can categorize vehicles in different ways.

For example, by layout (Figs 1.1–1.4), such as:

front engine driving the front wheels

front engine driving the rear wheels

front engine driving all four wheels

rear engine driving the rear wheels

mid-engine driving the rear wheels

mid-engine driving all four wheels.

The following paragraphs and bullet points highlight

features of the vehicle layouts mentioned above.

Common abbreviations for these layouts are given in

Table 1.1.

A common layout for a standard car is the front￾engine, front-wheel drive vehicle. This is because a

design with the engine at the front driving the front

wheels has a number of advantages:

It provides protection in the case of a front-end

collision.

Engine cooling is easier because of the air fl ow.

Cornering can be better if the weight is at the front.

Front-wheel drive adds further advantages if the

engine is mounted sideways-on (transversely).

There is more room in the passenger compartment.

The power unit can be made as a complete unit.

The drive acts in the same direction as the steered

wheels are pointing.

Rear-wheel drive from a front engine was the method

used for many years. Some manufacturers have

Overview and introduction

Figure 1.1 Front-engine, front-wheel drive Figure 1.2 Front-engine, rear-wheel drive

1 Overview and introduction

2

continued its use, BMW for example. A long propeller

shaft from the gearbox to the fi nal drive, which is part

of the rear axle, is the main feature. The propshaft has

universal joints to allow for suspension movement.

This layout has some advantages:

Weight transfers to the rear driving wheels when

accelerating.

Complicated constant velocity joints, such as used

by front-wheel drive vehicles, are not needed.

Four-wheel drive combines all the good points

mentioned above but makes the vehicle more

complicated and therefore expensive. The main

difference with four-wheel drive is that an extra

gearbox known as a transfer box is needed to link

the front- and rear-wheel drive.

The rear engine design has not been very popular but

it was used for the bestselling car of all time: the VW

Beetle. The advantages are that weight is placed on

the rear wheels, giving good grip, and the power unit

and drive can be all one assembly. One downside is

that less room is available for luggage in the front.

The biggest problem is that handling is affected

because of less weight on the steered wheels. Flat￾type engines are the most common choice for this

type of vehicle.

Fitting the engine in the mid-position of a car has

one major disadvantage: it takes up space inside the

vehicle. This makes it impractical for most ‘normal’

vehicles. However, the distribution of weight is very

good, which makes it the choice of high-performance

vehicle designers. A good example is the Ferrari

Testarossa. Mid-engine is the term used to describe

any vehicle where the engine is between the axles,

even if it is not in the middle.

Key fact

In a mid-engine car the distribution of weight is

very good.

1.1.2 Types and sizes

Vehicles are also categorized by type and size as in

Table 1.2.

1.1.3 Body design

Types of light vehicle can range from small two-seat

sports cars to large people carriers or sports utility

vehicles (SUVs). Also included in the range are light

commercial vehicles such as vans and pick-up trucks.

It is hard to categorize a car exactly as there are

several agreed systems in several different countries.

Figures 1.5–1.13 show a number of different body

types.

1.1.4 Chassis type and body panels

The vehicle chassis can be of two main types:

separate or integrated. Separate chassis are usually

used on heavier vehicles. The integrated type, often

called monocoque, is used for almost all cars. The two

main types are shown here in Figures 1.14 and 1.15.

Key fact

A vehicle chassis can be of two main types:

separate or integrated.

Table 1.1 Common abbreviations

FWD Front-wheel drive

RWD Rear-wheel drive

AWD All-wheel drive

4WD Four-wheel drive

Figure 1.3 Rear-engine, rear-wheel drive Figure 1.4 Mid-engine, rear-wheel drive

Table 1.2 Common abbreviations and defi nitions

LV Light vehicles (light vans and cars) with an MAM of up to 3500 kg, no more than eight passenger seats. Vehicles weighing

between 3500 kg and 7500 kg are considered mid-sized

LGV A large goods vehicle, known formerly and still in common use, as a heavy goods vehicle or HGV. LGV is the EU term for trucks

or lorries with an MAM of over 3500 kg

PCV A passenger-carrying vehicle or a bus, known formerly as omnibus, multibus or autobus, is a road vehicle designed to carry

passengers. The most common type is the single-decker, with larger loads carried by double-decker and articulated buses,

and smaller loads carried by minibuses. A luxury, long-distance bus is usually called a coach

LCV Light commercial vehicle; the formal term in the EU for goods vehicles with an MAM of up to 3.5 tonnes. In general language,

this kind of vehicle is usually called a van

MAM: maximum allowed mass; EU: European Union

Figure 1.5 Saloon car. (Source: Volvo Media) Figure 1.6 Estate car. (Source: Ford Media)

Figure 1.7 Hatchback. (Source: Ford Media) Figure 1.8 Coupé. (Source: Ford Media)

Figure 1.9 Convertible. (Source: Ford Media) Figure 1.10 Concept car. (Source: Ford Media)

Figure 1.11 Light van. (Source: Ford Media) Figure 1.12 Pick-up truck. (Source: Ford Media)

Figure 1.13 Sports utility vehicle (SUV). (Source: Ford Media)

Figure 1.14 Ladder chassis Figure 1.15 Integrated chassis