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.
New OBD compliance codes added, see section 22.214.171.124.
Clarifications to DM19, CVN and CAL ID message incorporated.
Proprietary SPN use clarifications and precautions added.
DM1 clarifications on lamp and lamp flash state use for EURO VI, see table 5 (table 24 removed and all references are
now to Table 5), see appendix K, and appendix I.
Added EURO VI to table 1, table 2, and to the OBD Compliance table as part of DM5. Added new diagrams relative to EURO VI, see Appendix H FIG H5-6 and Appendix K.
Added DM53 Active Service Only DTCs, DM54 Previously Active Service Only DTCs, and DM55 Service Only Clear All DTCs. The Service Only DTCs are not to be displayed to vehicle operators but used to convey information to service and repair locations.
Added clarification for DM5 and DM26 OBD readiness byte and bit order. Added clarification to DM1 to not use MIL lamp bits for conveying OBD readiness at Key On.
Incorporated updates for DM5, DM10, and DM26 SPN regarding byte placement.
Added another example use case to FMI 8.
Added to the Proprietary SPN reserved block.
Added language about Direct Lamp Control for lamp test, readiness,discrimentatory MIL. Add new DM7 option to get all OBD Test Results for all required monitors.
Added new DM56 for Model Year and Engine Certification Family.
Updated and clarified table 18 In-use Monitor Ratio Reporting
Updated appendix J table J1 to define SPN FMI for EGR catalyst.
Added DM19 requirements for Cal ID and CVN when reporting multiple pairs.
Added new networks to DM13, Stop Start Broadcast message, proprietary network #1 and #2 and J1939 Network #4.
Forward and Scope updated to the common format for the J1939 set of documents.
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