ISO 15031-6:20 15为机动车辆的电气/电子车载诊断（OBD）系统在检测到故障时需要报告的标准化故障诊断代码（DTC）提供了一致性。它还为与这些代码相关联的统一消息（文本描述符）提供了指导。 ISO 15031-6:20 15规定了以下定义的规则和指南:a)诊断故障代码格式，由寻址格式、结构和消息组成；b)SAE J2012-DA中包含的标准化故障诊断代码和描述集的描述。可以根据两种格式的两个不同列表来解码DTC的两个最高有效字节:DTC格式标识符0016和0416；以及c)SAE J2012中包含的被称为故障类型的标准化诊断故障代码子类型集的描述-DA（仅在使用3字节故障诊断码时适用）。 ISO 15031-6:20 15规定了定义新诊断故障代码的所有一般规则和指南。它参考了SAE J2012-DA（数字附件），其中包括所有标准化DTC（数字和文本描述符）以及所有称为故障类型的诊断故障代码子类型。

ISO 15031-6:2015 provides uniformity for standardized diagnostic trouble codes (DTC) that electrical/electronic On-Board Diagnostic (OBD) systems of motor vehicles are required to report when malfunctions are detected. It further provides guidance for uniform messages (text descriptor) associated with these codes. ISO 15031-6:2015 specifies the rules and guidelines for the definition of the following: a) the diagnostic trouble code format, which consists of addressing format, structure and messages; b) a description of the standardized set of diagnostic trouble codes and descriptions contained in SAE J2012-DA. The two most significant bytes of a DTC may be decoded according to two different lists in two formats: DTC Format Identifier 00₁₆ and 04₁₆; and c) a description of the standardized set of diagnostic trouble codes subtypes known as failure types contained in SAE J2012-DA (applies only when 3-byte DTCs are used). ISO 15031-6:2015 specifies all general rules and guidelines to define new diagnostic trouble codes. It references SAE J2012-DA (Digital Annex), which includes all standardized DTCs (number and text descriptor) as well as all diagnostic trouble codes subtypes known as failure types.