It appears there is just one coolant temperature sensor, and it is an input to the instrument cluster. From there the data is transmitted to the Engine Computer. If the sensor or its wiring are defective, a diagnostic fault code would be set directing you to that circuit. It is much more likely the instrument cluster is defective. That is a computer module so it is very unreliable compared to when gauges were simple circuits.
The only component location drawing I can find doesn't show the coolant temperature sensor. It only shows a cylinder head temperature sensor. There was a reference to the front of the engine as you already know. Another section referenced that sensor being on a hose to the heater core.
This drawing is from Mitchell ProDemand.
Thursday, January 28th, 2016 AT 4:23 PM