Air Flow Meter/Sensor: Description and Operation

Mass Air Flow Sensor Construction And Operating Characteristics:

PURPOSE

The Mass Air Flow Sensor converts the incoming air to a voltage signal that is measured by the ECM.

LOCATION

Mounted to the air cleaner box.

OPERATION

A heated wire is subjected to the incoming air flow.
As heat is dissipated by the wire an electrical signal is sent to the ECM. As the temperature of the wire decreases, so does it's resistence. The control circuit regulates current I in relation to the varying resistance value RH so that VA always equals VB. The ECM receives the voltage value from VA and converts it into an air flow rate.