Vehicle Interface – OpenXC

The Vehicle Interface (VI) is piece of hardware that connects
to the car’s CAN bus, translates proprietary CAN messages to the standard
OpenXC message format and sends the output over USB, Bluetooth,
or 3G/Ethernet/WiFi to a host device.

The OBD-II port has one standard pin pair for a single CAN bus, but many
automakers expose other buses on additional, non-standard pin pairs. For this
documentation, we’ll use this nomenclature:

OBD-II Pin Pair OpenXC Bus Name Other common name
6 (+) and 14 (-) CAN1 CAN high / CAN low from ISO 15765-4 and SAE-J2284
3 (+) and 11 (-) CAN2-1 Ford secondary, Chrysler CCD
1 (+) and 8/9 (-)* CAN2-2 Ford: infotainment, GM: J2411
* If available, Pin 8 on Ford B, C platforms and Pin 9 on Ford D platforms. This is typically not available.

Most vehicle data is available from CAN1, and all vehicle interfaces connect
to that

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