Air Flow Meter/Sensor: Description and Operation

Description

Mass Air Flow Sensor (MAFS) is a hot-film type sensor and is located in between the air cleaner and the throttle body. It consists of a tube, a sensor assembly and a honey cell and detects the intake air quantity flowing into the intake manifold.
While the intake air coming out of the air cleaner flows by the honey cell, it becomes laminar flow, and then it passes the hot-film. At this time, heat transfer is generated by convection and this sensor loses its energy. This sensor detects the mass air flow by using the energy loss and transfers the information to the ECM by frequency. By using this signal, the ECM can calculate fuel quantity and ignition timing.