Coolant Temperature Sensor Test

Disconnect electrical connector from coolant temperaute sensor. Coolant temperature sensor is installed in thermostat housing. Using a DVOM, check resistance between ECU connector terminal "C10" to sensor connector and ECU connector terminal "D3" to sensor connector. See Fig 1 .

If resistance is greater than one ohm, repair wiring harness. Measure resistance of sensor between sensor terminals. Refer to COOLANT TEMPERATURE SENSOR RESISTANCE table. Replace coolant temperature sensor if not within specification.

COOLANT TEMPERATURE SENSOR RESISTANCE ⁽¹⁾

°F (°C)

Ohms

212 (100)

185

160 (70)

450

100 (38)

1600

70 (20)

3400

40 (4)

7500

20 (-7)

13,500

0 (-18)

25,500

-40 (-40)

100,700

⁽¹⁾	Values given are approximate.

Fig 1: ECU Electrical Connector Terminal Identification

Courtesy of CHRYSLER MOTORS.