Coolant Temperature Sensors

The coolant temperature sensor is located within the engine cooling jacket. It measures temperature by means of electrical resistance. In most cases this is done using a negative temperature coefficient, that is to say, as the temperature increases, the resistance within the sensor decreases. 

A regulated voltage from the vehicles ECU, typically 9 volts, decreases with this resistance as it passes through the sensor. This lower voltage is returned to the ECU via the signal wire. The ECU can then calculate the engine temperature.

Manufactured to the highest standards, the Autotec range of coolant temperature sensors are available for a broad range of UK and European applications.