发动机维修1（Engine maintenance 1）.docVIP

发动机维修1（Engine maintenance 1） Electronic control engine maintenance skills (Tianjin Dongli District East China Automotive repair factory Xie Li) two pages, submenu1 preface, the next page Electronic control engine maintenance, based on understanding the working principle of the electronic components, determine the fault position is mainly to master the skills, according to the fault phenomena, from simple to complex, from easy to difficult,. Split into two, and gradually reduce the scope of the fault, until the fault location. Here are some of the electronic engine maintenance and judgment skills for readers to borrow. When the ignition switch turns to ON, will the engine fault light be lit to determine whether the power relay and the ECU are energized? The ignition switch to the computers power signal can be judged by the fault light, because the computer only receives the ignition switch power signal to output the signal, lights the fault lamp. Of course, check the premise in the faulty lamp bulb / line under normal conditions. This method is mainly used to determine whether the power signal of the ignition switch of ECU is working normally when not in the car. Open the tank cover, switch key, or start the engine. Do you hear the pump pump sound from the tank mouth to tell if the pump is working?. There are only 4 ways to control the gasoline pump: 1. according to the engine crankshaft speed control; 2. control by air flow panel; 3. control the speed of the fuel pump according to the working conditions (starting, idle speed, load); 4. by oil pressure and generator control. ECU makes the gasoline pump work generally consists of two steps (some models only second steps: 1) received signal to the ignition switch power supply pump relay output signal to the steam pump closed 3 - 5 seconds; 2 received control signal (above 4 one) to the pump relay output signal to the closed steam pump. Judge: open the ignition switch (ECU fault light) gasoline pump without 3 - 5 second