This document supersedes SAE J2012 APR2002, and is technically equivalent to ISO 15031-6:2005 with the exceptions described in Section 1.2.

This document is intended to define the standardized Diagnostic Trouble Codes (DTC) that On-Board Diagnostic (OBD) systems in vehicles are required to report when malfunctions are detected.

This document includes: a. Diagnostic Trouble Code format; b. A standardized set of Diagnostic Trouble Codes and descriptions; c. A standardized set of Dianostic Trouble Codes subtypes known as Failure Types