Cars · Wiring
OBD0 CN3 Serial Port Pinout and Function
OBD0 ECUs feature a 5-pin serial port labeled CN3 with pinout and functionality similar to OBD1 CN2.
OBD0 ECUs typically feature a 5-pin serial port labeled CN3. This port shares the same pinout and similar functionality to the OBD1 CN2 port.
Note
CN3 is the standard serial communication interface on OBD0 ECUs, enabling diagnostic and tuning access via serial protocol.