Engine Coolant Temperature Sensor

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.

Fig 1: Identifying Engine Coolant Temperature Sensor, Gasket And Terminal

Courtesy of NISSAN NORTH AMERICA, INC.

VOLTAGE AND RESISTANCE REFERENCE DATA

Engine coolant temperature

Voltage⁽¹⁾

Resistance

-10°C (14°F)

4.4 V

7.0 - 11.4 kΩ

20°C (68°F)

3.5 V

2.37 - 2.63 kΩ

50°C (122°F)

2.2 V

0.68 - 1.00 kΩ

90°C (194°F)

0.9 V

0.236 - 0.260 kΩ

⁽¹⁾	These data are reference values on the diagnosis tool.

Fig 2: Engine Coolant Temperature Sensor Resistance Graph

Courtesy of NISSAN NORTH AMERICA, INC.