On a standard OBD-II connector, what is the function of Pin 6?

Pin 6 on a standard OBD-II connector is designated as the CAN High communication line. This line plays a crucial role in vehicle data communication, especially in vehicles equipped with Controller Area Network (CAN) systems, which are commonly used for various electronic components in modern vehicles. The CAN protocol allows multiple microcontrollers to communicate with each other without a host computer, facilitating a more efficient exchange of information between different systems like the engine control unit, transmission control, and other modules.

Understanding this is important because the proper functioning of vehicle diagnostics relies heavily on effective communication over these pins. A malfunction in the CAN High line can impede the ability to gather diagnostic trouble codes (DTCs) and other vital information for vehicle repair and maintenance. Hence, recognizing the role of each pin in the OBD-II connector is essential for a smog repair technician, as it directly impacts the diagnostic capabilities of the vehicle.