5.4 发动机集中控制系统的其他功能5.4.1 故障自诊断功能故障自诊断是指ECU监测控制系统的工作状况,并在发生故障时,将故障信息以代码的形式存入存储器内,同时接通故障指示灯的电路,以告知驾驶员检查或维修发动机。其工作原理如下:系统正常工作时,ECU不断收到各种传感器输入的信号,而且ECU输入、输出信号的电平都是在规定范围内变化的;当ECU在一段时间内收不到某一传感器的输入信号,或 5.4 Other functions of engine centralized control system 5.4.1 Fault self-diagnosis function Fault self-diagnosis refers to the working status of ECU monitoring and control system and stores the fault information in the form of code in the event of a fault, Indicator light circuit to inform the driver to check or repair the engine. Its working principle is as follows: When the system works normally, ECU receives the signal that various sensors input constantly, and the level of ECU input, output signal all changes within the stipulated range; When ECU can not receive a certain period of time Sensor input signal, or