Airflow Meter

Airflow meter measures the mass flow rate of the incoming air. It then sends an output signal to the ECU, where output is converted into an intake air signal (engine load).

Air flowing around the hot wire removes heat. Temperature of the hot wire is very sensitive to the mass flow rate of air. The higher the temperature of the hot wire, the higher its resistance value. The change in temperature, or resistance, is determined by the mass flow of air.

After the engine is turned off, the ECU heats up the hot wire to approximately 1832°F (1000°C) to burn off dust which adheres to hot wire during vehicle operation. The self-cleaning operation occurs only if the engine is operated above 1500 RPM, after driving vehicle at 12 MPH or higher, and when cylinder head temperature is less than 239°F (115°C).