Sable V6-183 3.0L DOHC VIN S MFI (1997)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
Engine Coolant Temperature (ECT) Sensor
PURPOSE
The Engine Coolant Temperature (ECT) sensor measures varying engine coolant operating temperatures, providing the information to the Powertrain
Control Module (PCM). The ECT signal is used to modify ignition timing, EGR flow and air/fuel mixture.
OPERATION
The varying temperature, and thus varying resistance, affects the voltage drop across the sensor terminals, providing electrical signals to the PCM.
CONSTRUCTION
The ECT is a thermistor device in which resistance decreases as the temperature increases, and increases as the temperature decreases.
Thermistor-type sensors are considered passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of
the passive sensor causes a variation in total current flow.
