ISO 9141-2. This protocol has an asynchronous serial data rate of 10.4 kbit/s. It is somewhat similar to RS-232; however, the signal levels are different, and communications happens on a single, bidirectional line without additional handshake signals. ISO 9141-2 is primarily used in Chrysler, European, and Asian vehicles.
- pin 7: K-line
- pin 15: L-line (optional)
- UART signaling
- K-line idles high, with a 510 ohm resistor to Vbatt
- The active/dominant state is driven low with an open-collector driver.
- Message length is Max 260Bytes. Data field MAX 255.
IC3, IC4 are Si 9241aey or Si9243aey, both can be used but pins are diffrent
Used for Volkswagen, Audi, Skoda, Seat. + opel bu only K-line