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

MAT & CTS Sensor Characteristics:

PURPOSE
Measures intake air temperature.

LOCATION
On the air cleaner.

OPERATION
The Intake Air Temperature (IAT) sensor is a thermistor in series with a fixed resistor within the engine control module (ECM), that measures the temperature of the air entering the intake manifold. The ECM applies 5 volts to the sensor. The ECM monitors the voltage across the IAT sensor and converts it into a temperature reading. When the outside air temperature is cold, the IAT sensor resistance is high, and when the outside air temperature is warm, the IAT sensor resistance is low; Therefore, when the air temperature is cold the ECM will receive a low voltage input, and when the air temperature is warm the ECM will receive a high voltage input. The IAT sensor is located on the air cleaner.