故障现象一辆2005年产卡罗拉轿车,起动发动机时,有时需要2次或者2次以上才可以起动着机,每次起动,发动机曲轴在起动机的带动下都能正常转动,发动机起动后运转正常,车辆可以正常行驶,仪表盘上的发动机故障指示灯点亮。故障诊断用故障检测仪读取故障代码,故障代码为P0340,其含义是凸轮轴位置传感器电路故障。查阅该车维修手册,故障代码P0340的故障设置条件为:发动机起动或 Symptom A 2005 Corolla sedan, start the engine, sometimes need two or more than two can start the machine, each start, the engine crankshaft can be driven by the starter can be normal, the engine starts operating normally , The vehicle can travel normally, and the engine fault indicator on the dashboard lights up. Fault diagnosis Read fault code with fault detector, the fault code is P0340, which means the fault of the camshaft position sensor circuit. Check the car repair manual, fault code P0340 fault setting conditions are: engine start or