The Intake Air Temperature (IAT) sensor is a thermistor that changes its resistance in response to the engine intake air temperature. This sensor has two wires: 1 is for a 5-volt reference supply from the Powertrain Control Module(PCM), and the remaining wire is ground.
The variation in the reference voltage is monitored by the PCM to determine air temperature. If the intake air is cold, the resistance is high, which results in a high signal voltage. On the other hand, if the intake air temperature is high, the resistance decreases, resulting in a low signal voltage.
The OBDII DTCP0111 means that the PCM observed a change that exceeded the expected limit in a shorter time than expected in the AIT Sensor signal circuit.