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

Coolant Temperature Sensor:

CAUTION: A high input impedance digital volt-ohm meter (DVOM) is required when testing sensors on these vehicles. A low input impedance meter could seriously damage certain components of this system.

Disconnect the coolant temperature sensor electrical connector, and check the resistance across its two terminals. The resistance should be less than 1,000 ohms when the engine is at normal operating temperature. See the following resistance chart to verify that the coolant temperature sensor is within its range.


Temperature-to-Resistance Values
(Approximate)

~F ~C Ohms

212 100 185
160 70 450
100 38 1,600
70 20 3,400
40 4 7,500
20 -7 13,500
0 -18 25,000
-40 -40 100,700