Automotive Diagnostic Systems : Understanding OBD I and OBD II

Learn everything there is to know about automotive diagnostic systems.

The electronic control unit (ECU) and other electronic controls are connected to every major system of a car built within the past 20-plus years. However, when there is a problem or an error code, many enthusiasts do not know how to go about fixing the problem. Using this book, an affordable scanner, and other common tools, the average enthusiast can diagnose and fix most common problems, rather than bringing the vehicle to a dealership for repair with shop rates of $100 per hour or more.

In this revised edition, author Keith McCord recounts the history of automotive onboard diagnostic systems, the creation of the rudimentary OBD-I systems, and the development and evolution of OBD-II. Currently, OBD-II is the industry standard, and this book provides a thorough explanation of this system. The main features, capabilities, and characteristics are detailed. It shows how to access the port connector on the car, the serial data protocols, and what the serial data means. To understand the diagnostic trouble codes (DTCs), the numbering system is defined, and a table of common DTCs is shown. Most importantly, McCord provides a thorough process for troubleshooting problems and tracing a problem to its root, explaining why DTCs may not lead to the source of the underlying problem and ultimately resolving the problem. Also, this book will bring you up to date on the latest controller area network (CAN) bus systems necessary for the technology employed in the most modern automobiles.

Almost anyone can attach a scanning tool to the serial port and read the error code, but the key to fixing problems is using an effective troubleshooting process that resolves all the issues that may be contributing or creating the problem. McCord provides sound procedures, insight, and information for resolving most ECU and computer-control problems at home with affordable consumer-grade scanners.