J1939/73_202208 : Application Layer - Diagnostics - SAE International
Facilitates the movement of large data blocks, such as software updates or calibration files. Stop Start Broadcast: Sae J1939-73 Pdf
While robust, J1939-73 has limitations: it does not define flashing or reprogramming of ECUs (covered in J1939-73’s companion, J1939-71 for parameter assignment). Also, the original CAN at 250 or 500 kbps is becoming bandwidth-constrained for advanced diagnostics with many ECUs. SAE has therefore extended the standard to to support CAN FD (flexible data-rate) for larger payloads. J1939/73_202208 : Application Layer - Diagnostics - SAE
The J1939-73 standard updates roughly every 18–24 months. The 2023 and 2024 revisions introduced: SAE has therefore extended the standard to to
"The Heavy-Duty Truck's Diagnostic Puzzle: Cracking the SAE J1939-73 Code"
DM1 includes an occurrence count field (0–126). Many mechanics see a code and ignore the count. A count of 120 means the fault has happened repeatedly; clear and test drive before replacing parts.
The SAE J1939-73 PDF document covers several key aspects of the J1939 protocol, including: