Reno L4-2.0L (2006)
Intake Air Temperature Sensor: Description and Operation
Intake Air Temperature Sensor Description
The Intake Air Temperature (IAT) sensor is a thermistor, a resistor which changes value based on the temperature of the air entering the engine. Low
temperature produces a high resistance (4,500 Ohms at -40 degrees C [-40 degrees F]), while high temperature causes a low resistance (70 Ohms at
130 degrees C [266 degrees F]).
The Engine Control Module (ECM) provides 5 V to the IAT sensor through a resistor in the ECM and measures the change in voltage to determine the
IAT. The voltage will be high when the manifold air is cold and low when the air is hot. The ECM knows the intake IAT by measuring the voltage.
The IAT sensor is also used to control spark timing when the manifold air is cold. A failure in the IAT sensor circuit sets a diagnostic trouble code
P0112 or P0113.