Hello new to the forum and to my 2007 DTS. The display on my dash for the heat and AC was not working so I bought a used one on Ebay. I disconnected the battery took out the old unit, and plugged in the new one. Wala! it worked. but since then my tpms system says it need to re-learn the tire locations. And in addition my new key fob does not work @ all. Called cadillac, one service rider said I have to program the new Heat/AC control to my car???? It's got to be something simple. Any assist will be appreciated.