On Board Vehicle Diagnostics

Vehicle on-board diagnostics has been evolving rapidly over the last 20 years. What began as a small set manufacturer-specific tests and communication protocols has evolved into a complex, comprehensive diagnostic system able to detect literally hundreds of failures that could cause drivability concerns or emission increases. This rapid evolution has been driven, in part, by California’s OBD-II regulations as well as need for manufacturers to provide comprehensive diagnostics to allow technicians to service the complex engine and transmission controls on today’s vehicles. As the technology improves, states are relying on on-board diagnostics for Inspection/Maintenance programs in place of more costly tailpipe emission tests. The recent introduction of a standardized CAN communication link provides fast and easy access to internal control module data and opens the way for new wireless telematics technologies like prognostics and remote diagnostics. This paper explores the history and future opportunities brought about by this OBD technology.