OBD2 to USB Diagnostic Tool Adapter (ELM327 Analog) The interfaces support J1850 VPW, J1850 PWM, ISO-9141-2, ISO 14230 (KWP2000). Files: Project SCH&PCB - ORCAD 9.2 HEX File for PIC18F2455 Adapter Build Image

There are two primary ISO documents that describe how to perform OBD communications on K- line between a “tester” and a “vehicle”. There are actually several ISO and SAE documents, but these two are the main ones that describe all aspects of the