A Practical Approach to Motor Vehicle Engineeringand Maintenance
Pages : 505
Size : 14 MB
In this third edition some of the older technology has
been removed and modern technology to include Level
3 topics has been included. Much emphasis has been
placed on fault diagnosis because it is such an important
part of a modern automotive technician’s work.
The careful consideration of fault diagnosis that is
undertaken in a range of examples in this edition shows
how a methodical approach to fault diagnosis, based on
good knowledge of automotive systems, can lead to
As an example, the ECU may report the fault code
P0301 that tells us that there is a misfire in number 1
cylinder. The misfire may be caused by one or more
Ignition problem, defective spark plug, defective HT
cables, defective direct ignition coil, etc.
Poor compression, badly seating valve, leaking
gasket, worn or broken piston rings.
Incorrect mixture in that cylinder, air leak, defective
It is clear that good ignition in a single cylinder is
dependent on many factors, which must be taken into
account when considering what action to take. Faults in
some of these other areas may also be recorded in fault
codes, but others will not. To locate causes of faults in
these other areas may require use of specialist equipment,
and reference to manuals and circuit diagrams e these
factors are covered in detail in several of the examples
in this book. The methodical six-step approach is high-
lighted as a sound basis for successful fault diagnosis.
Outline of the diagnostic
1. Understand the problem.
Receive the customer and listen carefully to their
description of the problem.
Understand the symptoms and check to ensure that
they are understood before proceeding.
Make notes of details.
Carry out checks and make a visual examination.
Perform a road test if thought necessary.
2. Analyse the evidence e firm up the diagnosis.
3. Verify the problem e carry out tests to confirm the
4. Find the cause e use test equipment.
5. Perform the necessary repair e consult the customer
if there are alternatives.
6. Carry out thorough tests to ensure that the fault is
cured. Ensure that the vehicle is properly prepared for
return to the customer.
I have included a number of questions at the end of most
chapters. In most cases they are designed to tease out
certain points and I hope that readers will use them as
the basis of discussion with fellow students and tutors.
Where appropriate I have included my suggested