What is an OBD II connection?
OBD stands for On-Board Diagnostics.
Most 1996 and newer vehicles have standardized computer systems (also known as OBDII) that continually monitor the electronic sensors of engines and emission control systems, including the catalytic converter, while the vehicle is being driven to ensure they are working as designed.
The OBD II connection would typically be found under the steering wheel area or in the passenger footwell. The OBD II connection is used for the diagnostic machine to connect to, thus enabling access to the On Board Computer (ECU) for the purposes of fault analysis, software updates etc.