STANDARDS & COMMITTEES SAE J2012 and the changing world of diagnostic trouble codes Cal/Amp By Brian BUCK, Member of SAE's J2012 Diagnostic Trouble Code Task Force and Global Technical Lead at GM Aftersales and Engineering-Service Diagnostics and Programming. The world of diagnostic trouble codes (DTCs) is changing in a big way. SAE J2012, the industry standard method for creating and assigning common DTCs since the 1990s, is being updated in important ways to support the new SAE J1979-2 and SAE J1979-3 standards. The SAE J2012 Diagnostic Trouble Code Task Force is a subcommittee of the Vehicle EE System Diagnostic Standards Committee 38 March 2024 and has been hard at work for the last 18 months preparing for these changes in the base specification and the associated digital annex. Both updates will have downstream enhancements for the OEM community, the aftersales community, as well as facilities that provide inspection and maintenance testing and period technical inspection with standardized test equipment. The base SAE J2012 standard, which describes how DTC numbers are defined and partitioned, is being updated to support diagnostics in complex vehicle UPDATEhttps://www.sae.org/standards/content/j2012_201612/ https://www.sae.org/standards/content/j2012_201612/ https://www.sae.org/standards/content/j1979-2_202104/ https://www.sae.org/standards/content/j1979-2_202104/ https://www.sae.org/standards/content/j1979-3_202310/ https://standardsworks.sae.org/standards-committees/j2012-diagnostic-trouble-code-task-force https://standardsworks.sae.org/standards-committees/j2012-diagnostic-trouble-code-task-force