How do I know whether my vehicle is OBD2 compliant?

Commission Directive 70/220/EEC, Annex I: 8.1.

Vehicles with positive-ignition engines With effect from 1 January 2000 for new types and from 1 January 2001 for all types, vehicles of category M1, except vehicles the maximum mass of which exceeds 2500 kg, and vehicles of category N1 class I, must be fitted with an on-board diagnostic (OBD) system for emission control in accordance with Annex XI. [...]

Note that here "European Union" means countries which were members of the EU in 2000.

Commission Directive 70/220/EEC, Annex I:

8.2. Vehicles with compression-ignition engines Vehicles of category M1, except - vehicles designed to carry more than six occupants including the driver, - vehicles whose maximum mass exceeds 2500 kg, from 1 January 2003 for new types and from 1 January 2004 for all types, must be fitted with an on-board diagnostic (OBD) system for emission control in accordance with Annex XI.

Note that here "European Union" means countries which were members of the EU in 2003.

Other regions passed laws requiring OBD2 compliance for newer vehicles. Here is an approximate list of countries and model years where laws require OBD2 compliance for light duty vehicles.

If your vehicle does not fall into any of the above categories, look under the hood and try to locate a label that explicitly states that the vehicle was designed to comply with OBD-2 legislation.

In this case, OBD2 is used as a general term and can mean any of the following:

• OBD II (California ARB)
• EOBD (European OBD)
• JOBD (Japanese OBD)

You can also consult your vehicle owner's manual and perhaps contact your local dealer. However, be aware of the fact that many dealers do not know the difference between OBD and OBD2. If the vehicle is not OBD2 compliant, you cannot use a generic OBD2 scan tool to obtain diagnostic information from your vehicle.

No, not necessarily. A lot of European and Asian manufacturers equipped their vehicles with D-shaped 16-pin connectors long before they began installing OBD2 systems on those vehicles. One curious thing to note here is the fact that most non-EOBD compliant vehicles had a DLC that does not fully conform to SAE J1979.