汽车怠速故障（Idle speed fault）.docVIP

汽车怠速故障（Idle speed fault） The basic idea of troubleshooting difficult problems (1) confirmation of failure The electronically controlled engine control system (ECU) controls only the electronically controlled part of the engine, not the whole of the engine, especially the mechanical part. Electronically controlled engine computer ECU cannot monitor the trouble caused by the following causes. (1) the ECU of the general low grade car can not monitor the failure of the ignition circuit, pollution or damaged spark plug and the high-voltage ignition circuit caused by the breaking of the high-voltage wire. (2) ECU can not monitor the blockage of the inlet filter screen and the fuel filter pipe of the electric gasoline pump, the oil in the oil inlet pipe or the return pipe is flat and the oil is not free or the mixture is too thin. (3) ECU can not monitor the air filter inlet or air filter element blocking or throttling the cause of the changes in air flow caused by the fault. (4) ECU can not monitor the cylinder pressure high or low, or the pressure uniformity of each cylinder. (5) ECU can not monitor the plug and pin damage, but it will cause the fault code caused by this situation. (6) ECU can not monitor the bad grounding, but it will cause the fault code caused by this situation. (7) the ECU cannot monitor the leakage or throttling of the vacuum line in the vacuum control system of the vacuum booster. However, the vacuum of the intake manifold absolute pressure sensor will be monitored and the ECU will also record the fault code. The above 10 are the reasons that the electronic control engine can not monitor, so we should pay attention to the maintenance of the electronic control engine. Whether it is an electrical fault or a mechanical fault, it is necessary to correctly distinguish the occurrence parts and the performance features so that the fault can be accurately and quickly determined and eliminated. During the inspection, if the engine is defective and the engin