Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

Coolant Temperature Sensor Location:

To test the Coolant Temperature Sensor, located in the intake manifold, proceed as follows.

Coolant Temperature Sensor:

1. Remove the Coolant Temperature Sensor from the intake manifold.

Coolant Temperature Sensor Test:

2. With the sensing portion of the Coolant Temperature Sensor immersed in hot water, check resistance between the two terminals. The sensor should be held with its threaded housing 3 mm (1/8in.) away from the surface of the hot water.
Standard Values
Water Sensor
Temperature (°F) Resistance (Kohm)
32.....................5.9
68.....................2.5
104.....................1.1
176.....................0.3


3. If the resistance deviates from the standard value, replace the sensor.

Coolant Temperature Sensor Connector Test:

NOTE: If the temperature of the engine coolant is known, then the sensor may be tested at the connector.