What are the symptoms of a damaged BMW mass air flow sensor?
2 Answers
When the mass air flow sensor is damaged, symptoms such as unstable idling, lack of power during acceleration, black smoke emission, and even failure to start may occur. Common faults of the mass air flow sensor: Common faults of the mass air flow sensor include short circuits, open circuits in the wiring, or abnormal intake air signal. These faults can prevent the ECU from accurately measuring the amount of air entering the engine, leading to improper fuel injection control, resulting in either a too rich or too lean air-fuel mixture, which affects the engine's normal operation. Function of the mass air flow sensor: The function of the mass air flow sensor in a car is to monitor the amount of air entering the engine and convert this information into an electrical signal sent to the electronic control unit (ECU). The ECU uses this signal to determine the engine's fuel injection quantity. The mass air flow sensor affects the engine's power performance. The main causes of damage to the mass air flow sensor are the long-term failure to replace the air filter or the use of low-quality air filters, which can lead to excessive accumulation of dust on the sensor's hot wire over time. This accumulation can cause inaccurate or failed resistance values, and the dust can also lead to excessive dirt buildup on the throttle body.
Last time my BMW had issues, it was shaking like dancing at idle, and wouldn't move when I stepped on the accelerator during acceleration. Normally it only burns 8 liters of fuel per 100 kilometers, but at that time it soared to over 10 liters. The malfunction indicator light was also on, glaring red and quite annoying. The mass airflow sensor is responsible for intake measurement—if it's dirty or broken, it interferes with fuel control. I drove to the repair shop, where the mechanic used a computer to diagnose the trouble code and suggested cleaning or replacing it. After cleaning, it improved a bit, but eventually, I just replaced it with a new one for 800 yuan. Now it runs much smoother. Everyone should pay more attention to vehicle abnormalities before driving—don't delay like I did, as it can affect engine lifespan.
