The first generation of OBD systems – known as “OBD1” – was introduced in 1981. Because each vehicle manufacturer developed its own system, there was no standardization among this generation of technology.
As a result, manufacturer-specific OBD I systems required a variety of diagnostic software and hardware. In general, OBD1 vehicles were built through model year 1995.
In search of a better solution, the Environmental Protection Agency () later established standards for improved vehicle diagnostics. The resulting standards — known as “OBD 2,” “Global OBD II” or “Generic OBD 2” – are part of a system the Society of Automotive Engineers (SAE) developed to regulate automotive electronic diagnosis. OBD 2 is required for all vehicles (imported and domestic) sold in the U.S. beginning in 1996 which dictates the use of a common diagnostic link connector and software for monitoring fuel and emission systems. Technicians are able to use the same tool to test any OBD 2 compliant vehicle without special adapters or manufacturer-specific tools which are necessary for OBD1 vehicles.
OBD II systems are more sophisticated than OBD1 – they seek out potential problems sooner and alert the driver to these issues through the “Check” light or Malfunction Indicator Light ( ). By alerting the owner of malfunctions as they occur, repairs can be sought promptly, which results in fewer from the vehicle.