The malfunction diagnosis system that discussed in the paper uses car body network instead of the K and L line network, it unites the two abstract network to one, predigests the inner network more.

• 本文论述的车载故障诊断系统，使用车身网络CAN网取代故障诊断专用的K线、L线网络，将两种独立的网络合而为一，进一步简化车内网络的复杂程度。