ItsNotAFedora

I was able to capture the runaway temp + button and stopping it with the propellant from a compressed air can.

I found an easy way to treat the symptom when it occurs. It isn't a fix, but it is better than nothing. I give it a short blast from a can of compressed air turned upside down. This does a quick super cool of the button which stops the bad behavior every time. Twice recently the phantom button started up again after about ten minutes but the quick chill stopped it. It seems like a full "one Mississippi" count works the best. Full write up with picture here. I'll see if I can post a short video next time it happens but doubt that a 10MB limit will allow that.

Follow up. The runaway temperature increase has starting sporadically occurring again. Each time a quick hit of refrigerant immediately stopped the unwanted behavior. Hoping it stops once the weather cools off.

My 2013 Lincoln MKS with touch controls (FCIM) for audio and HVAC recently started having the runaway temperature + button problem. For those unfamiliar the temperature starts rising on it's own until it maxes out at 85. Using either the steering wheel or touch screen controls one can fight this trying to force the temperature down. In my case, the problem seemed to happen when the interior got really hot while parked. It would stop once I got the car cooled off a bit. Prior to the runaway temp increase issue, I noticed that the driver's side + button sometimes would not work when touched. These button work on capacitance and over time, heat seems to cause some defect with the driver's side temperature + button (see first photo below) on the front console. This defect causes the button to send inputs to the environmental control module as if someone was pressing the + button continuously. Turning off the HVAC is not a workaround because the car is programmed to turn the heat or air on as soon as it receives an input from any of the temperature +/- buttons. I tried something that, so far, has stopped the runaway temperature increase problem. About ten days ago, I got in the car and the temperature started increasing on it's own. I was bit surprised as the interior wasn't all that hot. Also, the phantom inputs were sporadic rather than continuous. I stopped by Wally World and bought a can of compressed air, the type for cleaning computers. My theory was that if heat caused the touch button to go off on its own, maybe super cooling that area would stop it. After said purchase, I started the car and the temperature was still increasing on its own. I inverted the can and hit is with a two or three second burst of the propellant (second photo below). The button and surrounding area frosted over and immediately the temperature stopped increasing on its own. The button appears to be completely dead (touching it does nothing) now and I have not experienced the runaway temperature increase since I super cooled the button. As previously stated, a dead + button on the panel is a minor inconvenience given the multiple ways to adjust the temperature, including voice controls.