You Should Know About The Car Compatibility with OBD-II

One of the ubiquitous questions asked by inCarDoc users is about the compatibility with OBD2. “What are the limits, not allowing the car to be compatible with OBD2?” - a question which is asked frequently. Step by step we will try to figure out all the nuances of OBD2 support.

WHAT DOES OBD-II MEAN?

OBD – acronym decrypts On-Board Diagnostic of the vehicle. OBD-II standard used since 1996 and allows electronics to engage with ECU software.

DOES MY CAR HAVE OBD-II?

All models sold in the USA after 1996 must be OBD-II compliant. Please note, that country does not mean"formal" brand's headquarter location, but rather destination country. Pay attention, not to the question: “Where the car was made?”, but to the question “Where did you buy it?”. Brief and in detail:

Cars produced since mentioned year supports OBD2

For example, Subaru Forester 1999 model/year, supplied to the USA must have OBD-II support. While a similar model for the EU might have no OBD-II in 1999. Also, need to mention that manufacturers might start to supply OBD-II compliant models bit in advance of formal legislation date.

To verify that your vehicle is OBD 2/OBD II compliant by looking under the hood for a sticker indicating compliance ("OBD-II compliant "or" OBD-II certified).

WHERE IS THE OBD-II CONNECTOR LOCATED?

To find out whether your car supports OBD-II standard, you may examine the 16 pin-out DLC - Diagnostic Link Connector of a trapezoidal shape. PINs from 1 to 16 have a special assignment, e.g. Pin 4 - Chassis Ground or Pin 16 - Battery Power.

The connector is located on the driver's side, under the dashboard.

WHAT COMMUNICATION PROTOCOL DOES THE VEHICLE USE?

The reason, why automobile may not be 100% compatible with OBD2, is Communication Protocol. However, this problem rarely concerns modern cars.

The OBDII standard includes hardware and software requirements for the vehicle. However, manufacturers have the opportunity to choose Communication Protocols. It is important to note that Engine Family is the main factor, not the manufacturer. Certification is only related to the engine.

The Communication Protocol is part of the program, and allow to transfer troubles on the scanner. Portable “for home use” scanners are usually adapted to a single Communication Protocol, while universal scanner consoles include the decoding software and firmware for all five protocols in their units.

Requirements for software include mandatory support for the car one of the protocols.

For example, the 1995 model year certificates for the SNS3.0VJG1EK (engine) Nissan Maxima is NOT fully obd2 compliant. AND SNS2.4VJG2EK (engine) Nissan Altima 100% support OBD2.

Today, OBD-II supports SAE J2012 – the latest standard which comprises the corresponding trouble codes -Diagnostic trouble codes (DTC’s).

Also, read: The difference between UDS and OBD protocols