F 250 4WD Super Duty V8-6.4L DSL Turbo (2008)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the
temperature increases, and resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor terminals
and provides electrical signals to the PCM corresponding to temperature.
A cooling system concern such as low coolant or coolant loss could cause an overheating condition. As a result, damage to major engine components
could occur. Using both the ECT sensor and fail-safe cooling strategy, the PCM prevents damage by allowing air cooling of the engine and limp home
capability.