Sensor, Coolant Temperature: Description

The Engine Coolant Temperature (ECT) sensor is used to sense engine coolant temperature. The ECT is located at the cylinder head on the left side.
The ECT sensor is a two-wire Negative Thermal Coefficient (NTC) sensor. Meaning, as engine coolant temperature increases, resistance (voltage) in the sensor decreases. As temperature decreases, resistance (voltage) in the sensor increases.