Intake Air Temperature (IAT) Sensor

IAT is a thermistor (variable resistor) wired in series with a fixed resistor inside ECM. IAT sensor measures temperature of outside air entering intake manifold. IAT sensor resistance changes with respect to intake air temperature. High intake air temperature decreases IAT sensor resistance. Low intake air temperature increases IAT sensor resistance.

Sensor resistance modifies a reference voltage that is supplied and monitored by ECM. The ECM uses this information to calculate intake air density and quantity of air. For IAT sensor locations, see INTAKE AIR TEMPERATURE SENSOR (IAT) LOCATION table.