Passport 4WD V6-3.2L SOHC (6VD1) (1994)
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Intake Air Temperature Sensor: Description and Operation
CONSTRUCTION AND OPERATION
The Intake Air Temperature (IAT) Sensor is a Thermistor, a Resistor which changes value based on the temperature of air entering the Engine.
Low temperature produces a high resistance (100,000 Ohms at -40°C/-40°F), while high temperature causes low resistance (70 ohms at 130°C/266
°F). The Engine Control Module (ECM) supplies a 5-volt signal to the sensor through a resistor in the ECM and measures the voltage. The
voltage will be high when the intake air is cold, and low when the air is hot. By measuring the voltage, the ECM knows the IAT. The IAT Sensor
is also used to control Spark Timing and delays Exhaust Gas Recirculation when intake air is cold. A failure in the IAT Sensor Circuit should set
either DTC 23-A/B.
