SAE J1939-73 Diagnostics Application Layer defines the SAE J1939 messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. Diagnostic messages (DMs) provide the utility needed when the vehicle is being repaired. Diagnostic messages 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. Diagnostic messages 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, or EU regulated OBD requirements are satisfied with a subset of the specified connector and the defined messages.
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Changes made to address issues identified during the development and of the SAE J1939-84 test capability.
Text added to limit the number of SPNs that need to be reported in DM24 for data stream, freeze frame or test results. Also made DM24 require the use of destination specific addressing.
Added Table H1 to define 3 different classes of OBD devices (primary, secondary and J1939 contributor)
References to SAE J1939-71 were corrected to take into account SAE J1939 Digital Annex creation.
Added the definition of an OBD Device.
Updated DM13 figures and Suspend Signal definition.
Updated figure H3 2013 ARB 13 CCR1971.1 J1939 Diagnostic Message Signal Chart.
Updated MIL On time (SPN 3295) and Time since code clear (SPN 3296), to have unique hybrid and non-hybrid requirements.