W 3500 L4-5.2L DSL Turbo (2006)
Intake Air Temperature Sensor: Description and Operation
Intake Air Temperature (IAT) Sensor
The intake air temperature (IAT) sensor is fitted between the air cleaner and turbocharger internal to the mass air flow (MAF) sensor. The IAT sensor 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.
