The volume air flow sensor is incorporated within the air cleaner; it functions to convert the amount of engine air intake to pulse signals of a frequency proportional to the amount of engine air intake, and to input those signals to the ECM. The ECM then, based upon those signals, calculates the amount of fuel injection and ignition timing.
The power for the volume air flow sensor is supplied from the MFI relay to the volume air flow sensor, and is grounded at the ECM. The volume air flow sensor, by intermitting the flow of the 5 volts applied from the ECM, produces pulse signals.