Diagnostic systems monitor everything from cylinder misfires to improperly closed gas caps. Starting with why we need scanners to work effectively on modern cars, this book teaches readers how to choose the right tool (from the bewildering array of scanners, ranging from hand-held units to computer software), how to use it, and what each code means. It also includes a complete guide to online information sources as well as a comprehensive list of codes. From hand-held, dedicated units to software that turns PCs and palm pilots into powerful diagnostic scanners, auto enthusiasts today have a variety of methods available to make use of on-board diagnostic systems. And, not only can they be used to diagnose operational faults, they can be used as low-budget data acquisition systems and dynamometers, so you can maximize your vehicle s performance. Beginning with why scanners are needed to work effectively on modern cars, this book teaches you how to choose the right scanner for your application, how to use the tool, and what each code means. How To Use Automotive Diagnostic Scanners is illustrated with photos and diagrams to help you understand OBD-I and OBD-II systems (including CAN) and the scanners that read the information they record. Also included is a comprehensive list of codes and what they mean. From catalytic converters and O2 sensors to emissions and automotive detective work, this is the complete reference for keeping your vehicle EPA-compliant and on the road!