Air Flow Meter

AIR FLOW METER (M1.7-M42 SYSTEMS)







To determine the proper air/fuel ratio, the total volume of air drawn into the engine is measured by an Air Volume Sensor. The sensor then produces a varying voltage signal, to the ECM that "represents" the inducted air volume.

A potentiometer is connected to the AFM flap and converts the mechanical movement of the sensing flap into an electrical signal to the ECM. The wiper arm of the potentiometer is linked directly to the sensing flap by its pivot shaft. As air flow causes the sensing flap to move, the wiper arm of the potentiometer sends a varying voltage signal to the ECM.

Attached to the sensing flap is a compensation flap that moves within a closed chamber. This creates a dampening effect on flap movement for pulsations in the intake system caused by cylinder filling and valve operation.