众所周知,汽车是由千百个零部件组成的有机整体,当某一零件的尺寸、位置或者性能发生变化时,相邻的零件或者相关的配合关系会发生微妙的变化。另一方面,新型汽车的电子控制系统越来越复杂,向着功能综合化和控制单元通信网络化方向发展。例如,动力系统控制模块(PCM)同时控制着发动机和自动变速器;无论是数据总线故障还是挂接在总线上的任何一个控制单元出现故障,都 As we all know, the car is composed of hundreds of parts of the organic whole, when a part of the size, location or performance changes, the adjacent parts or related relationship between the subtle changes. On the other hand, the new car’s electronic control system is more and more complex, to the functional integration and control unit communication network development. For example, the powertrain control module (PCM) controls both the engine and the automatic transmission; neither the data bus nor any of the control units attached to the bus fail