1 The most important conditions for the normal operation of the electronic control engine in the third country are that the low-pressure oil circuit and the high-pressure oil circuit can be established, the injector is free from faults, and the ECU, crankshaft sensor, camshaft sensor, water temperature sensor and oil pressure sensor are free from faults.

2. Digital multimeter, fault decoder and ordinary test lamp are commonly used in the maintenance of electronically controlled diesel engine, but in order to accurately and quickly determine the cause of the fault, some other practical test tools are needed, such as rail pressure quick test lamp, injector quick test controller, injector current test pliers, etc.

3. If the electronically controlled engine cannot be started, first check whether the engine ECU is powered on. When the key is turned on, the engine fault light will light up for a while. Otherwise, the engine ECU is not energized. Check the power cord of ECU, etc. If yes, check whether the fuel injector has current with current test pliers, and check whether the rail pressure can be established at idle speed and low speed with rail pressure quick test lamp. These two situations are indispensable.

4. If the engine can't start, directly measure the power supply current on the fuel injector with the current clamp. Generally, there is a current of about 150 Ma-350 Ma, indicating that there is basically no problem with the engine ECU.

5. If the injector current provided by the engine ECU is normal and the high pressure in the oil circuit is normal, it is difficult to judge whether the injector can inject oil. It is a very direct, simple and feasible method to use the rapid detection controller of injector provided by this station to check on the common injector calibrator (usually where the oil pump is checked). The injector rapid detection controller simulates the pulse voltage provided by the engine ECU, and the power-on time is only 3.5 milliseconds, and the intermittent time is 45 milliseconds (measured by oscilloscope), so as to quickly judge whether the injector is available.

6. The engine doesn't work well, the acceleration fails, the cylinder is broken, black smoke and blue smoke are emitted. , you can check the low-pressure oil circuit, high-pressure oil circuit, high-pressure pump, fuel injector, ECU, crankshaft sensor, camshaft sensor, accelerator pedal sensor, intake pressure sensor, etc. , and check and eliminate them one by one according to the fault codes provided by the decoder. The key point is to check whether the rail pressure measured by the rail pressure quick test lamp changes correspondingly when the accelerator pedal is added or subtracted.

7. The basic points of troubleshooting for the electronic control engine of National III are the oil pressure in the oil circuit, whether there is a signal in the circuit and whether the injector can work normally. Automobile fault decoder can only provide approximate fault direction, and sometimes the fault information provided is not accurate.