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故障现象一辆福特嘉年华车,行驶里程约为8万km,搭载有可变气门正时系统(VVT)的1.5 L发动机和4速自动变速器,因发动机故障灯异常点亮而进厂检修。故障诊断接车后试车验证故障。发动机能够正常起动,但转速偏低。此外,仪表上发动机故障灯也已点亮,说明故障确实存在。连接IDS读取故障代码,得到3个故障代码(图1)。根据故障代码的提示分析认为,故障应该与气门正时有关。用IDS读取数据流,查看配气相位正时提前的实际数值(图2),显然,正时提前的实际值与PCM所需要的数值存在很大的偏差。至此,可以基本确定发动机故障灯异常点亮
Fault phenomenon A Ford Fiesta car, mileage of about 80,000 km, equipped with a variable valve timing system (VVT) 1.5 L engine and 4-speed automatic transmission, the engine fault light abnormal lighting into the plant overhaul. After the fault diagnosis test car to verify the fault. The engine can start normally, but the speed is low. In addition, the engine fault light on the instrument has also been lit, indicating that the fault does exist. Connect the IDS read the fault code, get 3 fault codes (Figure 1). According to the fault code prompt analysis, the fault should be related to the valve timing. Using IDS to read the data stream, check the actual value of the timing advance of the gas phase (Figure 2). Obviously, the actual value of the timing advance deviates greatly from the value required by the PCM. At this point, it is basically possible to determine that the engine fault lamp is abnormally lit.