J1939/73_200609 Application Layer - Diagnostics



Issuing Committee
The SAE J1939 series of recommended practices are intended for light- and heavy-duty vehicle uses on- or off-road as well as appropriate stationary applications which use vehicle-derived components (e.g. generator sets). Vehicles of interest include, but are not limited to: on- and off-highway trucks and their trailers, construction equipment, and agriculture equipment and implements.
The purpose of these documents is to provide an open interconnect system for on-board electronic systems. It is the intention of these documents to allow electronic devices to communicate with each other by providing a standard architecture.
J1939-73 identifies the diagnostic connector to be used for the vehicle service tool interface and defines messages to accomplish diagnostic services. California, EPA, or EU regulated OBD requirements are satisfied with a subset of the specified connector and the defined messages. 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.
This SAE Recommended Practice has been updated to support manufacturers’ new requirements, and new On Board Diagnostic (OBD) regulatory requirements for light duty, medium duty and heavy duty vehicles. These cover the needs of US EPA, US CARB, EU, and World Wide Harmonization of OBD. The following updates made: APPENDIX G, listing non-OBD fault management narratives, DM22 (Individual Clear/Reset of Active and Previously Active DTC), DM23 (Previously Active Emission Related Faults), DM24 (SPN Support), DM25 (Expanded Freeze Frame), and DM26 (Diagnostic Readiness 3), a revised definition for DM6, and updates to the DM1 for lamp flashing and a fixed 1 second update rate, DM27 (All Pending DTCs), DM28 (Permanent DTCs), DM29 (Regulated DTC Counts), DM30 (Scaled Test Results),DM31(DTC to Lamp Association), DM32 through DM52, and the addition of 2 new FMIs (FMI 20 Data Drifted High, and FMI21 Data Drifted Low).
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SAE International Recommended Practice, Application Layer - Diagnostics, SAE Standard J1939/73_200609, Revised September 2006, Issued February 1996, https://doi.org/10.4271/J1939/73_200609.
Additional Details
Sep 8, 2006
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Content Type
Recommended Practice