Rio Cinco L4-1.6L DOHC 16V (2003)
Air Flow Meter/Sensor: Description and Operation
The Mass Air Flow (MAF) Sensor is the most direct method of measuring engine load because it measures the mass of air intake. This is also known as a
"hot-wire" sensor because it depends on the measurement of current flowing through heated wires to measure air flow. The hot wire is heated to specific
temperature differential above incoming air. Two wires inside the MAF Sensors are exposed to a portion of the airflow entering the engine:
The ambient temperature wire or "cold wire" isn't heated so this wire is the temperature of the surrounding air and serves as the reference temperature.
The hot wire is heated by the MAF to be a certain amount above the ambient air. As soon as air flows over the wire, both wires are cooled. The control
circuits then apply more voltage to keep the hot wire at the original temperature differential. This creates a voltage signal monitored by the ECM. The
greater the air flow and wire cooling, the greater the signal.
