The symptom you are describing wouldn't be caused by a bad temperature sensor.  Most likely it is a bad control panel with a stuck Temperature button.

Less likely but not something you can rule out is a bad connection of the control panel or a bad circuit board (portion that interfaces with the control panel).

Only way to resolve this with 100% certainty is by parts substitution.  Control panel would be replaced 1st and if problem is still there then the circuit board is replaced.  It likely is the control panel though, so I would suggest you buy that. 50% restocking charge if it is returned.  Send a picture of Control Panel as well as the serial #s and I can see if we carry yours.  Send to my email directly [email protected]

Dieter