Data link connector

he control modules of a given vehicle and access on-board diagnostics and live data streams.

OBD-II diagnostic connector

Type A female connector

Type B female connector

The OBD-II DLC (post-1996 vehicles) is usually located under the instrument panel on the driver side, though there are several exceptions. The SAE J1962 specification provides for two standardized hardware interfaces, called type A and type B. Both are female, 16-pin (2x8), D-shaped connectors, and both have a groove between the two rows of pins. But type B has the groove interrupted in the middle, so it isn't possible to plug a type A male connector into a type B socket. It is possible, however, to mate a type B male plug in a type A female socket.

The type A connector is used for vehicles that use 12V supply voltage, whereas type B is used for 24V vehicles and it is required to mark the front of the D-shaped area in blue color.

The OBD-II connector is required to be within 2 feet (0.61 m) of the steering wheel or somewhere within reach of the driver).

See also

• OBD-II PIDs – list of data readable with a scan tool
• ELM327 – common integrated circuit inside scan tools
• OBDuino – onboard computer made with Arduino that has the scan tool functions