The original on-board diagnostics (OBD-I) refers to most cars manufactured 1981 – 1995. Unfortunately, due to no clear set of standards for OBD-I cars, there are different ways used to communicate and interface with the car’s computer, which allowed for multiple interpretations amongst vehicle manufacturers. The following tables highlight the differences for domestic makes. All you have to do is choose the correct adapter cable.
Beginning in 1996, all passenger cars and light trucks (8,500 lbs. GVW or less) built for sale in the U.S. were required to be OBD II-compliant. In California, the GVW limit is 14,000 lbs. GWV stands for Gross Vehicle Weight. This information usually can be found on a sticker located on the driver’s doorframe.
Vehicles over 8500 lbs (14,000 lbs. California) are considered heavy duty and are exempt from the requirement to be OBD-II compliant. Usually a scanner from the manufacturer or from a higher end tool company is required in order to interface with heavy-duty vehicles.
Although some 1994 & 1995 vehicles are OBD-II compliant, no OBD-II vehicles were manufactured before 1994.
Here are three ways to determine if your vehicle is OBD II equipped:
- All OBD-II cars and light trucks will have a 16-pin “D” shaped diagnostic connector. If your connector has fewer pins, don’t worry. Manufacturers are not required to use all 16 pins and they can use them as they see fit. It should be located on the driver’s side, under the dash near the steering wheel. Connector placement may vary slightly depending on the manufacturer. Please Note: Some 1994 & 1995 vehicles (most notably GM) may be equipped with the OBD-II 16 pin connector but are not OBD-II compliant. For these vehicles, be sure to check the VECI decal as outlined in #2 below.
- Refer to the Vehicle Emissions Control Information Decal that is located in the engine compartment.
- Refer to the manufacturer’s certified service manual containing emissions information.
Note: Many 1996 and newer vehicles (notably heavy-duty trucks) are equipped with the 16-pin OBD-II connector, but they do not link with OBD-II scanners. Plugging one of our scanners into a non-compliant vehicle will not damage the vehicle or the tool. A Link Error message will be displayed on the scanner.