DTC P0101: MAF System Performance: Description

Mass Airflow (MAF) sensor is an airflow meter that measures amount of air entering engine. Powertrain Control Module (PCM) uses MAF sensor signal in order to provide correct fuel delivery for a wide range of engine speeds and loads. A small quantity of air entering engine indicates deceleration or idle. A large quantity of air entering engine indicates an acceleration or high load situation. MAF sensor has an ignition 1 voltage circuit, a ground circuit and a signal circuit. PCM applies a voltage to sensor on signal circuit. Sensor uses voltage in order to produce a frequency based on inlet airflow through sensor bore. PCM uses barometric pressure, throttle position, and engine RPM in order to calculate a predicted MAF value. PCM compares actual MAF sensor signal to predicted MAF value in order to determine if signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. DTC sets if actual MAF sensor signal is not within a predetermined range of calculated MAF value.