The standard defines over 60 diagnostic messages that facilitate both real-time monitoring and repair-shop diagnostics.
The document is the definitive standard for the diagnostic application layer in heavy-duty vehicles, such as trucks, buses, and agricultural machinery. It defines the specific messages, known as Diagnostic Messages (DMs) , and the Diagnostic Trouble Codes (DTCs) used to report and troubleshoot issues across a vehicle's Electronic Control Units (ECUs) . Current Version and Access sae j193973 pdf exclusive
: Tracks how many times the fault has happened. Strategic Use Cases The standard defines over 60 diagnostic messages that
: Used to Clear/Reset previously active DTC information. such as trucks
: Identifies the failed component (e.g., Engine Oil Pressure).