Ford onboard diagnostic trouble codes are alphanumeric codes generated by the vehicle's onboard diagnostic computer when it detects a problem with the car or truck. Typically, a professional vehicle repair provider can read and decipher these codes using a diagnostic computer. Car owners can purchase diagnostic code readers at many major auto parts supply stores and access a list of code definitions for a specific vehicle online.
OBD systems were first installed in new vehicles during the 1990s. These systems were very basic; the codes could often be interpreted in different ways and were generally effective only for gross mechanical failures. As of 2015, modern vehicles use the OBD II system, which provides more comprehensive diagnostics and more in-depth information on the vehicle's emissions systems.
When either an OBD or OBD II system detects a problem, it generates a code and illuminates the vehicle's check engine light. This light alerts the driver that the car needs to be checked by a diagnostic reader to ascertain the problem.
OBD computers generate two different types of codes. A generic code is one that represents a standard problem or issue, such as a vehicle misfire. Generic codes are standard among all vehicle manufacturers and do not vary. Enhanced codes are specific to each manufacturer and can represent problems with equipment specific to a certain vehicle model.