DTC P0101: Mass Airflow Sensor System Performance: Description

Mass Airflow (MAF) sensor measures amount of air entering engine during a given time. PCM uses MAF sensor information for fuel delivery calculations. MAF sensor readings during acceleration are much higher than those during deceleration or idle.

PCM calculates what MAF sensor reading should be when received from sensor under certain conditions using engine speed (RPM), throttle position, and barometric pressure parameters. When certain test conditions are met, PCM will compare its calculated MAF value to actual value received from sensor. If difference is too great, DTC will set.