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]
OBD systems give the vehicle owner or repair technician access to the status of the various vehicle sub-systems. The amount of diagnostic information available via OBD has varied widely since its introduction in the early 1980s versions of onboard vehicle computers. Early versions of OBD would simply illuminate a tell-tale light if a problem was detected, but would not provide any information as to the nature of the problem. Modern OBD implementations use a standardized digital communications port to provide real-time data and diagnostic trouble codes which allow malfunctions within the vehicle to be rapidly identified.
- ^ CarTechBooks. "OBD-I & OBD-II: A Complete Guide to Diagnosis, Repair & Emissions Compliance". CarTechBooks. Retrieved September 15, 2023.
- ^ "Regulations for Emissions from Vehicles and Engines". US Environmental Protection Agency. April 15, 2016. Retrieved June 2, 2024.