"Purpose This document supersedes SAE J1979 Apr 2002@ and is technically equivalent to ISO 15031-5:2006@ with the addition of new capabilities required by revised regulations from the California Air Resources Board (see Section 1.2). This document is intended to satisfy the data reporting requirements of On-Board Diagnostic (OBD) regulations in the United States and Europe@ and any other region that may adopt similar requirements in the future. This document specifies: a. message formats for request and response messages@ b. timing requirements between request messages from external test equipment and response messages from vehicles@ and between those messages and subsequent request messages@ c. behavior of both the vehicle and external test equipment if data is not available@ d. a set of diagnostic services@ with corresponding content of request and response messages@ to satisfy OBD regulations@ This document includes capabilities required to satisfy OBD requirements for multiple regions@ model years@ engine types@ and vehicle types. Those regulations are not yet final for some regions@ and are expected to change in the future. This document makes no attempt to interpret the regulations and does not include applicability of the included diagnostic services and data parameters for various vehicle applications. The user of this document is responsible to verify the applicability of each section of this document for a specific vehicle@ engine@ model year and region. This document is based on the Open Systems Interconnection (OSI) Basic Reference Model in accordance with ISO/IEC 7498 and ISO/IEC 10731 which structures communication systems into seven layers as shown in Table 1. Differences from SAE J1979 APR2002 The following are the technical differences between this document and the preceding SAE J1979: APR2002. Modifications to the ISO/DIS 15031-5:April 30@ 2002 (basis for SAE J1979 APR2002) prior to publication of ISO 15031-5: 2006: ? Section 4 ?C ""Symbols and Abbreviated Terms"" was added@ which changed all subsequent section numbers ? Paragraph 5.2.2.4 ?C Implementation guidance example for ISO 9141-2 and ISO 14230-4 protocols ? Paragraph 5.2.2.7 ?C Implementation guidance example for ISO 15765-4 protocol ? Paragraph 5.2.4.3.5 ?C Data not available test conditions for protocols: ISO 9141-2@ ISO 14230-4 and SAE J1850 ? Paragraph 5.2.4.3.7 ?C Data not available test conditions for protocol: ISO 15765-4 Diagnostics on CAN ? Paragraph 5.2.6 ?C Invalid Signals ? Paragraphs 6.1.1 and 7.1.1 ?C Added note about mandatory support of Service $01@ PID $00 ? Paragraphs 6.6.1 and 7.6.1 ?C Additional discussion for Service $06 data for OBD monitors that have multiple tests ? Paragraph 6.9.3.3 ?C Additional description for the MessageCount parameter based on InfoType ? Paragraph 7.1.1@ 7.2.1@ 7.6.1@ 7.8.1@ and 7.9.1 ?C Added clarification for support of requests containing multiple data items ? Paragraph 7.6.3.4 ?C Example for Use of Standardized Test IDs for Misfire Monitor ? Paragraph 7.9.4.2 ?C Added InfoType $0A for ECU name ? Paragraph B.2 ?C Added discussion of signals received via distributed networks ? Appendix B ?C Added PIDs $4F to $5A ? Appendix G ?C Added InfoTypes $09 and $0A for ECUNAME Modifications since publication of ISO 15031-5:2006@ and addition of new data requirements from the California Air Resources Board: ? Paragraph 7.2.4.2 ?C Added example Case #3 to clarify reporting of multiple freeze frames ? Section 7.10 ?C Service $0A for ISO 15765-4 - Request Emission-Related Diagnostic Trouble Codes with Permanent Status ? Paragraph B.2 ?C Clarification of signals received via distributed networks and added example figure ? Paragraph B.3 ?C Inferred Signals ? Paragraph B.4 ?C Revised PID structure used for newer PIDs ? Appendix B ?C Added Figure B2 that illustrates sensor and actuator definitions and locations ? Appendix B ?C Updated PIDs $01 and $41 to include support for compression ignition engines (Byte B@ bit 3 used to indicate different descriptions for Byte C and Byte D) ? Appendix B ?C Added Figure B3 to explain the use of PIDs $13 and $1D to determine how many data bytes will be reported for Service $01@ PIDs $06 to $09 and PIDs $55 to $58. ? Appendix B ?C Additional values and descriptions for PID $1C to specify OBD requirements ? Appendix B ?C Consistent use of ""LAMBDA"" instead of ""EQ_RAT"" for external test equipment to display equivalence ratio for PIDs $24 to $2B@ $34 to $3B@ and $44 ? Appendix B ?C Added PIDs $5B to $87 ? Appendix D ?C Renamed ""Oxygen Sensor"" to ""Exhaust Gas Sensor"" in multiple OBDMIDs; Added OBD MIDs in the range between $85 to $99 and $AE to $B3 ? Appendix E ?C Added Unit and Scaling IDs $34 to $39 and $B1 ? Appendix G and the example in Paragraph 7.9.4.2 ?C Expanded InfoType $08 In-use Performance Tracking data for compression ignition engines; Modified InfoType $0A for ECUNAME Additional differences: ? Minor rewording of Paragraphs 1 and 2 ? Use of ""."" instead of ""@"" to indicate decimal values ? Some of the message examples for diagnostic service definitions have been modified to demonstrate different possible responses@ and to include use of newly added data values NOTE: Both this document and the ISO 15031-5 document are intended to satisfy the requirements of OBD requirements in the United States and Europe@ and any other region that may adopt similar requirements in the future. Those regulations change with time@ and often when a requirement is introduced in one region@ it will later also become a requirement in another region. The ISO task force responsible for ISO 15031-5 and the SAE task force work closely together to maintain consistency in diagnostic reporting requirements in these two documents@ and to ensure usability of these documents for all regions. The goal is to maintain identical technical content in the two documents@ but this document may need to change if additional capabilities are required for the U.S. before the ISO document can be modified to include those changes. "
SAE J1979-2007 history
2024SAE J1979DA-2024 J1979-DA, Digital Annex of E/E Diagnostic Test Modes
2023SAE J1979DA-2023 J1979-DA, Digital Annex of E/E Diagnostic Test Modes
2023SAE J1979-3-2023 Brake-Stroke Indicator Design Guideline for Cam or Disc Air-Brake Actuators
2022SAE J1979DA-2022 J1979-DA, Digital Annex of E/E Diagnostic Test Modes
2022SAE J1979-3-2022 E/E Diagnostic Test Modes: Zero Emission Vehicle Propulsion Systems on UDS (ZEVonUDS)
2021SAE J1979DA-2021 J1979-DA, Digital Annex of E/E Diagnostic Test Modes
2021SAE J1979-DA-2021 Digital Annex of E/E Diagnostic Test Modes (See Also SAE J1979; Includes Access to Additional Content)
2019SAE J1979DA-2019 J1979-DA, Digital Annex of E/E Diagnostic Test Modes
2019SAE J1979-DA-2019 Digital Annex of E/E Diagnostic Test Modes (See Also SAE J1979)
2017SAE J1979DA-2017 J1979-DA, Digital Annex of E/E Diagnostic Test Modes
2017SAE J1979-DA-2017 Digital Annex of E/E Diagnostic Test Modes (See Also SAE J1979)