Sentra L4-1.8L (QG18DE) (2004)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
ECT SENSOR
Component Description
The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The
modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature.
The electrical resistance of the thermistor decreases as temperature increases.
CAUTION: Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the ECM's transistor. Use ground other
than ECM, such as body ground.