I have a '15 Rubicon JKU and the ATC works well when the vehicle first starts up but drive it for awhile and as soon as the temp is satisfied it never come back on. When you are driving in cold weather that means windows ice up and it gets really cold inside. I've taken it in twice, the friggen dealership won't drive it long enough for it to happen to them so as far as they are concerned there isn't anything wrong. I really wish I had found one with manual controls when I had bought this one. Any luck getting help from someone other than the dealer?

 

I would request that one of the techs ride with you while you show them whats happening.

My wife's WK2 has the ATC and it should come back on once the temps in the vehicle rise or go lower than whatever temp you set it too. Or as soon as you manually increase the speed of the fan or hit the defrost button, it will go into manual mode until you hit the "auto" button.

 

I have it in my 2011 and really dislike it. Primarily because the temperature settings for heat are 'max' (which is the breath from hell) then the next down from that is like 86 degF and that's not warm enough.. so you can cook yourself or have lukewarm temperature.