Onboard Diagnostics 1 (OBD1) Trouble Codes

The onboard diagnostics 1 (OBD1) system was designed for light and medium duty vehicles older than 1996. The system uses diagnosis trouble codes (DTCs) to alert you when a vehicle experiences a malfunction. DTCs help vehicle mechanics and owners with a rich expertise in vehicle maintenance understand problems with the vehicle and where the root of the vehicle’s problem or problems may lie. Different DTCs represent specific problems in your vehicle. The DTCs are not standardized, as they vary from manufacturer to manufacturer.

These codes were created by the Society of Automotive Engineers (SAE) to help vehicles comply with emission regulations. SAE is now called SAE International, and it is the professional organization that develops standards for automotive engineers.