POST UPDATED IN May, 2021
The Intake Air Temperature sensor is a thermistor and, in some cases, it is integrated with the MAF Sensor. It has 2 cables: one ground and the other 5-volt signal. The resistance is approximately 100 ohms when the air is at about 10 ° C, and when the air is at about 130 ° C, the resistance would be about 70 ohms, indicating that when the temperature increases, the internal resistance of the transducer, which is located inside the sensor, decreases, and in this way there is a lower voltage between the pull-up voltage and the voltage drop that causes the decrease in the resistance of the sensor.
Its function is similar to that of the ECT sensor (Engine Coolant Temperature) because it has a negative coefficient. It also contributes to the ECM (Engine Control module) to decide the amount of mixture to be injected, since the positive ions inside the injector can vary due to the air temperature. In this way, the Engine Control Module makes the decision to make the injection pulse wider or not.