Q: Do all cars have an OBD system?

Virtually all vehicles from the 1987 model year to the present day have an OBD system. Some earlier model year vehicles, but not all, have some semblance of an OBD system. However, their diagnostic abilities are severely limited.

There are several levels of on-board diagnostics, starting with OBD 0. This system was used by Asian vehicle manufacturers and provided minimal control functions. Domestic vehicle manufacturers started with OBD I, which was used from about 1987 to 1995. In 1996, OBD II was employed for greater monitoring and control of vehicle systems. All manufacturers have greatly enhanced their OBD II systems over the past 20 years, but we have not applied the OBD III name at this time.