I drive a 2014 Chevy Silverado LT 5.3L 2WD. Driving only 20 minutes in December weather, parked then noticed cooling fans running high, and temperature gauge reading 160, then I shut off the truck and the cooling fans continued running for a few minutes then stopped. I started the truck and the fans started up again. The check engine light turned on, so went to get it tested at the auto parts and got a P0128 Coolant Thermostat trouble code. I purchased a Coolant temperature sensor because weather was cold and AC was not being used. Upon replacing the sensor the following day while engine was cold, I started the truck and fans turned on again. I did go and buy a Thermostat kit with housing, disconnected the battery and replaced the Thermostat, restarted the truck and fans didn't turn on and temperature gauge indicating a rising temperature.