SAE International has released a new version of the J1939-73 document. It specifies diagnostics messages (DMs).
THE 190-PAGES DOCUMENT DEFINES CAN messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. The specification has been released first in 1996; the last version was published in 2015. The updated version replaces approximately 54 places, where a cross reference was lost in the publication process resulting in reference of “See 0”. It also replaces many other lost links found during review. Additionally, some confusing formatting is fixed.
The specified DMs provide the utility needed when the vehicle is being repaired. They are also used during vehicle operation by the networked electronic control modules to allow them to report diagnostic information and self-compensate as appropriate, based on information received.
DMs include services such as periodically broadcasting active diagnostic trouble codes, identifying operator diagnostic lamp status, reading or clearing diagnostic trouble codes, reading or writing control module memory, providing a security function, stopping/starting message broadcasts, reporting diagnostic readiness, monitoring engine parametric data, etc. California, EPA (Environmental Protection Agency), or Europe Community regulated OBD (on-board diagnostics) requirements are satisfied with a subset of the specified connector and the defined messages.
News and reports