On-board diagnostics (OBD) is a term referring to a vehicle's self-diagnostic and reporting capability. In the United States, this capability is a requirement to comply with federal emissions standards to detect failures that may increase the vehicle tailpipe emissions to more than 150% of the standard to which it was originally certified. [1][2]
Modern on-board diagnostic systems take a lot of the guesswork out of figuring out what's wrong with your vehicle. Learn how OBD works.
A car repair resource site that helps you diagnose vehicle OBD, OBD-II, and OBD2 problems. We have many articles on how to diagnose and repair many check engine light codes.