IAT Sensor

The scan tool range is -40°C to 151°C (-40°F to 304°F). The PCM converts the resistance of the intake air temperature sensor to degrees. The PCM uses the intake air temperature (IAT) to adjust fuel delivery and spark timing according to incoming air density. The IAT is also compared to the engine coolant temperature (ECT) at startup in order to identify cold starts for the HO2S heater and the EVAP diagnostics.