Volume Airflow Meter (VAF)

The VAF is mounted in the air inlet, between air cleaner and throttle body. It measures the volume of air entering into the engine by monitoring the position of a movable door. A potentiometer, attached to VAF door, signals door position to the PCM. The PCM translates door position to volume of air entering the engine.

The VAF also contains an air temperature sensor. The temperature of air entering the engine is monitored and transmitted to the PCM. The PCM is programmed to compute airflow and air temperature, so fuel flow can be adjusted to obtain optimum air/fuel mixture. The VAF also contains a fuel pump switching circuit to cut fuel pump operation when the engine is off.