What is OBD?

OBD-II is a standard enforced on vehicle manufactures to allow to on-board diagnostic information.

Modern vehicles rely upon computers to control and monitor all aspects of the vehicle's operation. Today's car contains numerous on-board electronic control units (ECU's) which are advanced computers responsible for engine management, transmission, anti-lock brakes and many other functions too.

Each ECU relies upon a variety of sensors to monity vehicle operation such as speed, engine RPM, coolant temperature, and oxygen sensors. While driving, if the vehicle's on-board computer system detects a problem the computer reports the error using a DIagnostic Trouble Code. A Diagnostic Trouble Code number is the method by which the ECU reports a problem with the vehicle. Only scan tools may be used to access these diagnostic trouble codes.