The MAF Sensor (Mass Airflow Sensor) tells the PCM (Powertrain Control Module) the amount of air entering the engine by a series of voltages. This data is used to calculate the engine load, the amount of fuel needed to inject, and the time when gear changes are necessary.
When the voltage sent by the MAF Sensor to the vehicle computer is below normal values, even though it is within the range set by the manufacturer, the DTC code P1102 OBDII will be set.