Engine Coolant Temperature (ECT) Sensor
WARNING: This page is about a different car, the 2011 Ford F550 Super Duty and 2011 Ford F450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The ECT sensor is a 2-wire thermistor which changes resistance as temperature changes. The resistance of the sensor increases as engine temperature decreases and the voltage measured by the PCM increases. The PCM uses this information to determine TCC operation.
Intake Air Temperature (IAT) Sensor
The IAT sensor is a thermistor which changes resistance as temperature changes. The resistance of the sensor decreases as the air temperature increases. The IAT provides air temperature information to the PCM which is used to determine transmission line pressure and shift scheduling.