Mass Airflow Sensor

Mass Airflow (MAF) sensor is located in throttle body. Sensor is a resistor with voltage applied to maintain resistor at a constant high temperature. When intake air flows past resistor, resistor cools off and additional voltage is required to keep resistor at high temperature. Measured voltage is used to determine quantity of air flowing in to engine. PCM uses this signal to control fuel mixture, ignition timing and other outputs.