Airflow Meter

All models except Supra, use a potentiometer type airflow meter incorporating an air temperature sensor. Supra models use an airflow meter which has a lumimus diode and a photo transistor. The lumimus diode emits light which reflects off of a mirror to the photo transistor.

The airflow meter causes incoming air to swirl into a vortex. When air swirls, it vibrates a leaf spring which has the mirror attached to it. As the mirror moves, the photo transistor picks up the movement of reflected light. The airflow meter sends this signal to the ECU.