本文件规定了诊断服务的数据链路独立要求，该要求允许诊断测试仪（客户机）控制车载电子控制单元（ECU、服务器）中的诊断功能，如电子燃油喷射、自动变速箱、防抱死制动系统等，该系统与嵌入道路车辆中的串行数据链路相连。 它指定了通用服务，允许诊断测试仪（客户端）停止或恢复数据链路上的非诊断消息传输。 本文件不适用于两个电子控制单元之间车辆通信数据链路上的非诊断信息传输。 然而，为了利用车辆通信数据链路上的诊断服务来执行双向诊断数据交换，本文件不限制ECU中的车载测试仪（客户端）实现。 本文件未规定任何实施要求。

This document specifies data link independent requirements of diagnostic services, which allow a diagnostic tester (client) to control diagnostic functions in an on-vehicle electronic control unit (ECU, server) such as an electronic fuel injection, automatic gearbox, anti-lock braking system, etc. connected to a serial data link embedded in a road vehicle. It specifies generic services, which allow the diagnostic tester (client) to stop or to resume non-diagnostic message transmission on the data link. This document does not apply to non-diagnostic message transmission on the vehicle's communication data link between two electronic control units. However, this document does not restrict an in-vehicle on-board tester (client) implementation in an ECU in order to utilize the diagnostic services on the vehicle's communication data link to perform bidirectional diagnostic data exchange. This document does not specify any implementation requirements.