What protocol is used to connect to a car?

The protocol, as a means of communication, is automatically determined when connecting to the control unit: KWP-1281, KWP-2000, CAN, or UDS. It is impossible to change the connection protocol.

If the car supports CAN/UDS connection, a check is performed to see if the control unit supports this type of connection. If it is not available, regular data transmission via K-Line is used for further processes.