Coolant Temperature Sensor/Switch (For Computer): Description and Operation

The Engine Coolant Temperature (ECT) Sensor, detects the temperature of engine coolant and supplies the Information to Electronic Control Assembly (ECA).

The ECT sensor is threaded into the heater outlet fitting or cooling passage on the engine. For engine control applications, the ECT signal is used to modify ignition timing, EGR flow, and air to fuel ratio as a function of engine coolant temperature. On electronic instrument cluster applications, the ECT output is used to control a coolant temperature indicator.