The volume air flow sensor directly measures the amount of the air flowing into the engine. The sensor is mounted between the air cleaner assembly and the air cleaner outlet tube.
The sensor utilizes a shutter valve that measures the amount of air entering the engine. The sensor does this by sending a signal, generated by the sensor as the shutter opens and closes, to the PCM. The signal is used by the PCM to calculate the injector pulse width, which controls the air/fuel ratio in the engine. The sensor and plastic housing are integral and must be replaced if found to be defective.
The volume air flow sensor also contains an intake air temperature sensor and fuel pump switch.