Air Temperature Sensor ( Ambient / Intake ): Description and Operation

The air temperature sensor, located in the air intake elbow, is a negative temperature coefficient (NTC) thermistor. NTC means that the resistance of the thermistor decreases as the sensed temperature increases. The air temperature.sensor construction differs from the coolant temperature sensor in that the thermistor element is exposed by holes in the tip of the housing. The holes are designed to allow fast response in measuring air temperature changes while at the same time providing the necessary mechanical protection. Pin 1 of the sensor is connected to ground through the ECM. The ECM applies 5 volts to pin 2 of the sensor and monitors the voltage across the sensor pins. The theoretical full voltage range is from 5-0 volts representing maximum cold to maximum hot.

The ECM convents the monitored voltage into a digital number that is used to control the ignition timing strategy.

Intake Air Temperature Sensor:

Temperature Charts: