OBD II was mandated for all vehicles sold in the United States in 1996.

• A. True
• B. False
• C. Not sure
• D. Unknown

Answer: (A)

OBD-II became a federal requirement for all new light-duty vehicles produced for sale in the United States starting with the 1996 model year. That means from 1996 onward, every new car and light truck sold in the US had to include the OBD-II system, with a standardized diagnostic port, codes, and data formats. Earlier OBD-I systems varied by manufacturer and weren’t mandated in the same universal way, so the 1996 model year deadline is what made OBD-II universal for new vehicles. In other words, the rule targets model-year 1996 vehicles, not necessarily calendar year 1996, which is why the statement is true. This standardization also brought a common 16-pin connector and consistent trouble codes, making diagnostics across different makes much easier.