The main purpose of this Recommended Practice is to verify that vehicles are capable of communicating a minimum subset of information, in accordance with the diagnostic test services specified in SAE J1979: E/E Diagnostic Test Modes, or the equivalent document ISO 15031-5: Communication Between Vehicle and External Equipment for Emissions-Related Diagnostics – Part 5: Emissions-related diagnostic services.
Any software meeting these specifications will utilize the vehicle interface that is defined in SAE J2534, Recommended Practice for Pass-Thru Vehicle Programming.
Changes have been made to this document in order to keep pace with changes made to the California Air Resources Board legislation: Title 13, California Code Regulations, Section 1968.2, Malfunction and Diagnostic System Requirements for 2004 and Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines, 1971.1. On-Board Diagnostic System Requirements--2010 and Subsequent Model-Year Heavy-Duty Engines, and Regulation (EC) No 715/2007 of the European Parliament and of the Council of June 20, 2007 on type approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information as amended by Commission Regulation (EC) 692/2008.
Some clarifications and functional enhancements have also been included in this document.