Engine Coolant Temperature Sensor Operation

The engine coolant temperature sensor provides an input to the Powertrain Control Module (PCM) on circuit K2. The sensor also operates the engine coolant temperature gauge in the instrument cluster on circuit G20. Description and Operation

From circuit K2, the engine coolant temperature sensor draws up to 5 Volts from the PCM. The sensor is a variable resistor. As coolant temperature changes, the resistance in the sensor changes, causing a change in current draw. The K2 circuit connects to cavity 28 of the PCM connector, and cavity 1 of the sensor connector.

The PCM provides a ground for the engine coolant temperature sensor signal (circuit K2) through circuit K4. Circuit K4 connects to cavity 51 of the PCM connector and cavity 2 of the sensor connector