Build an Arduino/ESP32 OBD2 K-Line Tool
Older cars often speak K-Line instead of CAN. This Arduino/ESP32 library offers a practical starting point for connecting to those ECUs, provided you add a proper protected transceiver. The repository’s examples and source should confirm supported protocols, timing, wiring, and diagnostic commands before any vehicle connection.
Read the build on github.com: Build an Arduino/ESP32 OBD2 K-Line Tool