汽车用的SAEJ1979协议资料，很重要的哦-Automotive SAEJ1979 agreement with the data, it is very important, oh

包括了iso14230和saej1979，iso14230规定了OBD2系统的物理层以及数据链路层，saej1979是应用层的协议-Includes iso14230 and saej1979, iso14230 provides OBD2 system, as well as the physical layer data link layer, saej1979 is the application layer protocol