扫描工具：第一代协议

[中文适用范围]： SAE J1978-1 指定了 OBD-II 扫描工具提供的一组补充功能。这些功能提供对符合 SAE J1978-1 的任何车辆上所有受监管的 OBD（车载诊断）服务的完整、高效和安全的访问。本文档的 SAE J1978-1 内容旨在满足 OBD-1 的要求。 II 扫描工具符合美国现行车载诊断 (OBD) 法规的要求。本文件规定： 一种在配备 OBD 的车辆和 OBD-II 扫描工具之间建立通信的方法。由 OBD-II 扫描工具提供的一组诊断服务，以便执行 SAE J1979 和 SAE J1979-2 中定义的服务。 SAE J1978 文档系列的介绍，其中 SAE J1978-1 涵盖 SAE J1979 中定义的第一代协议功能，SAE J1978-2 涵盖 SAE J1979-2 中定义的第二代协议功能。 [外文原描述]： SAE J1978-1 specifies a complementary set of functions to be provided by an OBD-II scan tool. These functions provide complete, efficient, and safe access to all regulated OBD (on-board diagnostic) services on any vehicle which complies to SAE J1979.The content of this document is intended to satisfy the requirements of an OBD-II scan tool as required by current U.S. OBD regulations.This document specifies:• A means of establishing communications between an OBD-equipped vehicle and an OBD-II scan tool.• A set of diagnostic services to be provided by an OBD-II scan tool in order to exercise the services defined in SAE J1979. In addition, SAE J1978-1 covers first generation protocol functionality defined in SAE J1979 plus automatic protocol determination for all SAE J1979/J1979-2/J1979-3 application content.• The presentation of the SAE J1978 document family, where SAE J1978-1 covers first generation protocol functionality defined in SAE J1979 and protocol determination for SAE J1979, SAE J1979-2, and SAE J1979-3, and SAE J1978-2 covers second generation protocol functionality defined in SAE J1979-2.The SAE J1978 document family does not preclude the inclusion of additional capabilities or functions in an OBD-II scan tool. However, it is the responsibility of the OBD-II scan tool designer to ensure that no such capability or function can adversely affect either an OBD-equipped vehicle, which may be connected to the OBD-II scan tool, or to the OBD-II scan tool itself.