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

Intake Air Temperature Sensor:

PCM Wiring:

Voltage Versus Temperature Chart:

DESCRIPTION
This sensor measures the temperature of the air/fuel mixture in the intake manifold, and sends this information to the PCM. The IAT sensor is a thermistor whose resistance changes as a function of temperature. When the temperature is low, the resistance is high. Resistance decreases as the temperature increases. The IAT sensor is a two wire sensor that receives a reference or signal voltage from the PCM.

PURPOSE
The IAT sensor provides intake air temperature information to the PCM for the use in calculating intake air density. The PCM uses IAT, MAP, and engine speed to calculate the quantity of air flowing into the engine. A failure in the IAT sensor circuit should set a code P037 or P038. An intermittent failure can set a code P071.


LOCATION
Top right hand side of engine, under intake manifold cover.