Normal parameters of Cruze air flow sensor

Under normal circumstances, the air flow signal data at idle speed is about 2.5g/s; If it is less than 2.0g/s, the air intake system is leaking; If it is greater than 4.0g/s, it means that the engine has extra load. The normal value of air flow of each engine is different. The greater the displacement, the greater the air flow value.

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The air flow signal is one of the main signals that the engine electronic control unit (ECU) controls the concentration of mixed steam. If the intake air volume increases, the injection quantity controlled by ECU is also large, and vice versa. Faults of air flow sensors can be divided into two categories. One is that the signal exceeds the specified range, indicating that the air flow sensor is faulty.

Modern electronically controlled vehicles have fail-safe function. When the signal of a sensor fails, the electronic control unit (ECU) will replace it with a fixed value, or replace the signal of the faulty sensor with the signal of other sensors. After the air flow sensor fails. ECU replaces it with the signal of throttle position sensor.

The other is inaccurate signal (i.e. performance drift). Inaccurate air flow sensor signal may be more harmful than no signal. This is because. Because the signal is not beyond the specified range. The electronic control unit (ECU) will control the fuel injection quantity according to this inaccurate air flow signal, so it will often cause the mixed steam to be too thin or too rich. If there is no air flow signal, ECU will use the signal of throttle position sensor instead, and the idle speed of the engine is relatively stable.

The electronic control unit (ECU) will control the fuel injection quantity according to this inaccurate air flow signal, so it will often cause the mixed steam to be too thin or too rich. If there is no air flow signal, ECU will use the signal of throttle position sensor instead, and the idle speed of the engine is relatively stable.

Finally, because the signal of the air flow sensor is the main basis for controlling the air-fuel ratio, the infrared exhaust gas analyzer can be used to measure the exhaust gas composition of the engine at idle speed and 2000 rpm.

If it is too different from the standard value, it is likely to be a fault caused by poor performance of the air flow sensor.