All I can do is tell you to check the cts wiring circuit. How many wires to the sensor, 2? If two wires that should be voltage and ground, key on, use digital multimeter.
You could take those wires loose on both ends and do an ohms test.
Maybe instrument cluster--computer--or a wiring circuit somewhere.
Maybe you have air in the coolant system, that can effect your gage.
Tuesday, November 10th, 2015 AT 11:56 AM