Intake Air Temperature Sensor Location - Page 585
Intake Air Temperature Sensor: Description and Operation
Intake Air Temperature (IAT) Sensor
The intake air temperature (IAT) sensor is internal to mass air flow (MAF) sensor. It is a variable resistor. The IAT sensor has a signal circuit and a low
reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT
signal circuit and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature
increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT signal circuit. With lower sensor
resistance, the ECM detects a lower voltage on the IAT signal circuit.
