Day 6 - Coolant Temperature Sensor

Measurement:

Water Temperature	Resistance
20℃	2.5kΩ
30℃	1.8kΩ
40℃	1.3kΩ
50℃	900Ω
60℃	670Ω
70℃	490Ω
80℃	303Ω
85℃	239Ω
90℃	200Ω

Graph:

Coolant Temperature Sensor or Engine Coolant Temperature

It is usually a negative temperature co-efficient thermistor.(NTC-as the temperature increases, the resistance decreases) ECT sensor usually has two wires and located near a coolant passage.

The purpose of ECT sensor is to let ECU know what the engine temperature is.

Reference site: http://www.howstuffinmycarworks.com/CTS_coolant_temp_sensor.html
http://www.aa1car.com/library/coolant_sensors.htm
http://www.auto-repair-help.com/auto_diagnostics/coolant_temperature_sensor.php