3
Auto Engine Performance and Driveability is designed
to help you diagnose and repair the complex engine and
computer control systems on the automobile. Most com-
plaints related to engine performance result from problems
caused by the failure of a sensor, output device, or compo-
nent. Troubleshooting today’s vehicles takes complex test
procedures, much service information, and elaborate test
equipment. In addition, fuel economy and exhaust emis-
sions must be closely controlled to meet federal and state
guidelines.
For you, the technician, knowledge is the key to servicing
a vehicle. Reading is a necessity to absorb the information in
manuals, troubleshooting charts, and schematics. Some basic
knowledge of mathematics and electrical theory is necessary
to understand the operation of computer control systems and
how those systems affect the vehicle. Experimentation and
random parts changing can no longer be performed. Both
are simply too time-consuming and expensive.
You must be able to use service information, test
equipment, and, most importantly, your reasoning and
logic skills to find the cause of a problem. Simply being
able to perform diagnostic tests is not enough. You must
be able to evaluate the test results to determine what they
mean. Chapters 12 and 13 provide you with a seven-step
diagnostic process that will help you locate the cause of
performance problems. This seven-step process can also
be used in diagnosing any system, not just those that are
automotive related. Once you learn this process, you will
find it invaluable in other automotive classes.
Auto Engine Performance and Driveability has been
written to help you develop those skills necessary to prop-
erly diagnose and fix driveability problems. Each chapter
of the textbook begins with learning objectives that pro-
vide focus for the chapter. A list of technical terms used in
the chapter appears after the objectives. These terms are
printed in bold italic type and are defined when first used.
Society of Automotive Engineers (SAE J1930) standardized
sensor and electronics terminology is used throughout the
text. Each chapter concludes with a summary and review
questions. Additionally, the following features appear
throughout the book.
Note: A note may highlight important
technical information, present information
related to the topic, or cross-reference
the material.
Caution: A caution identifies a situation that
may result in damage to the vehicle, tools,
or equipment if the proper procedure is not
followed.
Warning: A warning identifies operations
that have the potential for injury.
One of the reasons you are reading this book is to
prepare for ASE certification, which is important for any
technician. To help you in this area, ASE-type questions
are included at the end of every chapter. Advanced ASE
questions are included in the advanced chapters. These
questions require reading schematics, referencing trouble
codes, and analyzing data. These questions are similar to
those found on the ASE Advanced Engine Performance
(L1) test. One of the final chapters is devoted to a detailed
explanation of the ASE test procedures, including how to
register for and take the tests.
Introduction