Engine Coolant Temperature Sensor

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

Check resistance between engine coolant temperature sensor terminals as shown in the figure.

Fig 1: Checking Resistance Between Engine Coolant Temperature Sensor

Courtesy of NISSAN MOTOR CO., U.S.A.

< Reference data >

ENGINE COOLANT TEMPERATURE SENSOR REFERENCE DATA

Temperature °C (°F)	Resistance kΩ
20 (68)	2.1 - 2.9
50 (122)	0.68 - 1.0
90 (194)	0.236 - 0.260

If NG, replace engine coolant temperature sensor.

Fig 2: DTC P0128 Thermostat Function - Temperature/Resistance Graph
Courtesy of NISSAN MOTOR CO., U.S.A.