SAE J1939-73 defines the diagnostics and communication diagnostics (DM) messages and procedures used on the J1939 vehicle network (CAN-based) for heavy-duty and off-highway vehicles. If you work with commercial-vehicle electronic control units (ECUs), telematics, or fleet diagnostics, J1939-73 is essential for implementing health reporting, fault codes, and retrieval of diagnostic data over the vehicle network.
Between 180 and 240 pages, depending on revision. The 2024 version is 218 pages including 50+ pages of SPN tables. Sae J1939-73 Pdf
SAE J1939-73 is a standard developed by the Society of Automotive Engineers (SAE) that defines the Diagnostics layer of the J1939 communication protocol. While the J1939 family as a whole governs how electronic control units (ECUs) communicate in heavy-duty vehicles, J1939-73 specifically outlines the procedures for identifying and reporting system failures, retrieving diagnostic data, and configuring vehicle parameters. It is the industry standard for diagnostic communication in commercial vehicles, agricultural machinery, and construction equipment. SAE J1939-73: Practical Guide for Vehicle Network Engineers
The SAE J1939 series is a standard developed by the Society of Automotive Engineers (SAE International) for vehicle bus networks used in trucks, buses, agricultural tractors, and off-highway equipment. It is based on the CAN 2.0B protocol (29-bit identifier). What is SAE J1939-73
SAE J1939-73 specifically covers the Application Layer – Diagnostics. Officially titled "Diagnostic Application Layer," this document outlines:
Simply put, if you want to read a check engine light on a CAT, Cummins, or Detroit Diesel engine, you must decode it using J1939-73.