论文部分内容阅读
故障现象一辆上海桑塔纳志俊轿车,怠速不稳,加速不畅,在高速上行驶过程中,仪表盘上的发动机故障指示灯(也叫EPC灯)异常点亮(图1)。故障诊断接车后试车,没发现有什么明显的异常,但仪表盘上的发动机故障指示灯点亮,这说明该车电控系统确实有故障。但是用故障检测仪查询发动机控制单元的故障存储时却没有故障代码,发动机故障指示灯点亮的情况不能清除。在试车过程中发现,挂在3挡时怠速行走,发动机的运转是处于游车状态,发动机转速不是很平稳,怀疑是气缸压力
Symptom A Shanghai Santana Zhijun sedans, idling instability, poor acceleration, the process of driving at high speed, the dashboard engine fault indicator (also called EPC lamp) abnormal light (Figure 1). Fault diagnosis After the test car, did not find any obvious abnormalities, but the dashboard engine fault indicator light, indicating that the car does have electrical control system failure. However, when using the fault detector to check the fault memory of the engine control unit, there is no fault code. The fault of the engine fault indicator can not be cleared. Found in the test process, hanging in the 3 block idle speed walking, the engine is running in the state of the car, the engine speed is not very stable, the suspect is the cylinder pressure