CSS J1939-73 DBC File
Heavy Duty Diagnostics (DM1, DM2, …)
The SAE J1939-73 DBC file contains decoding rules for converting J1939 diagnostic messages (DM1, DM2, …) to ‘physical values’. This lets you identify issues in e.g. trucks, tractors and buses.
DBC is a CAN database format used in most automotive tools – incl. CSSCAN software/APIs.
The download includes a legal J1939-73 DBC and license, based on the J1939-73 PDF standard (also included). CSS offer this in collaboration with SAE.
Tip: You can combine this with CSS J1939 DBC.
What is a DBC file?
A DBC file is a standardized method for storing the “rules” on how to interpret raw CAN bus data. In particular, it contains details on what ‘signals’ (e.g. RPM, Vehicle Speed, …) are contained within which ‘messages’ (i.e. CAN IDs).
In the J1939 standard, messages are referred to as Parameter Group Numbers (PGN) and signals as Suspect Parameter Numbers (SPN).
Further, a DBC file includes names, descriptions, positions and lengths of the signals – as well as how to offset and scale them.
This DBC file download includes:
- A J1939-73 DBC file with details for DM1, DM2, …, DM52
- The J1939-73 standard PDF
- One legal license (1 user, 1 PC) matching the J1939-73 license
CSS Electronics acts as a re-seller for the Society of Automotive Engineers (SAE) for the J1939 database file. Terms include the SAE terms related to purchase.
When is the database useful?
CSS J1939 protocol is used across most heavy-duty vehicles, including commercial trucks, tractors, transit buses etc. Because the protocol is standardized, you can use CSS J1939 DBC file to decode data across the majority of heavy-duty vehicle brands/models.
CSS J1939-73 DBC file complements CSS J1939 DBC by adding decoding information on the CSS J1939 diagnostic messages, also known as DM1, DM2 etc. These messages contain critical information on potential issues in a heavy-duty vehicle through warning lamp statuses and Diagnostic Trouble Codes (DTC). The latter contain information on which part of the vehicle has issues (through an SPN identifier) and e.g. what type of failure is present (though a failure mode identifier).