KWP2000最初是基于K线的诊断协议，由于K线物理层和数据链路层在网络管理和通讯速率上的局限性，使得K线无法满足日趋复杂的车载诊断网络的需求。而CAN网络（Controller Area Network）由于其非破坏性的网络仲裁机制、较高的通讯速率（可达1M bps）和灵活可靠的通讯方式，在车载网络领域广受青睐，越来越多的汽车制造商把CAN总线应用于汽车控制、诊断和通讯-KWP2000 initial diagnosis is based on K-line protocol, as K line physical layer and data link layer in the network management and communication speed on the limitations, making K lines can not meet the increasingly complex vehicle diagnostic networks. The CAN network (Controller Area Network) network because of its non-destructive arbitration mechanism, the higher the communication rate (up to 1M bps) and the flexible and reliable means of communication, in-vehicle networking is widely popular, more and more cars manufacturers to CAN bus used in automotive control, diagnosis and communication