. This is a real-time broadcast that screams "Active Fault!" across the CAN bus. It includes a Diagnostic Trouble Code (DTC)
: Identifies the standard diagnostic connector (typically the J1939-13 9-pin Deutsch connector) used for service tool interfaces . Key Diagnostic Messages (DMs) sae j193973 pdf exclusive
Full PDF versions are generally not "free" or public; they require a license from the SAE Standards Store. sae j193973 pdf exclusive
Diagnostic communication is organized into "DMs." Each DM has a specific purpose: DM1 (Active DTCs): Periodically broadcast to show current issues. DM2 (Previously Active DTCs): Used to retrieve historical fault data. DM11 (Clear Active DTCs): sae j193973 pdf exclusive