Rodeo 2WD V6-3.2L (2003)
Intake Air Temperature Sensor: Description and Operation
The intake air temperature (IAT) sensor is a thermistor which changes its resistance based on the temperature of air entering the engine. Low temperature
produces a high resistance of 100,000 ohms at -40 °C (-40 °F). High temperature causes low resistance of 70 ohms at 130 °C (266 °F). The PCM
supplies a 5-volt signal to the sensor through a resistor in the PCM and monitors the signal voltage. The voltage will be high when the incoming air is
cold. The voltage will be low when the incoming air is hot. By measuring the voltage, the PCM calculates the incoming air temperature. The IAT sensor
signal is used to adjust spark timing according to the incoming air density.
The Tech 2 displays the temperature of the air entering the engine. The temperature should read close to the ambient air temperature when the engine is
cold and rise as underhood temperature increases. If the engine has not been run for several hours (overnight), the IAT sensor temperature and engine
coolant temperature should read close to each other. A fault in the IAT sensor circuit will set DTC P0112 or DTC P0113.
