Component Tests and General Diagnostics

1. Ensure ignition is in the OFF position, then disconnect coolant temperature sensor electrical connector and connect a digital volt/ohmmeter between sensor terminals.
2. Measure resistance between sensor terminals. Resistance should be 7.0-13.0 K Ohms.
3. Run engine until coolant temperature reaches approximately 200°F, then measure resistance. Resistance should be .7-1.0 K Ohms.
4. Proceed as follows:
a. Measure wiring harness resistance between Powertrain Control Module (PCM) terminal 28 and coolant sensor harness connector. Resistance should not exceed 1 ohm.
b. Measure wiring harness resistance between Powertrain Control Module (PCM) terminal 51 and coolant sensor harness connector. Resistance should not exceed 1 ohm.
5. If resistance is not as specified, replace coolant sensor or repair wiring harness.