Why is my 2012 Toyota Camry touch screen not working?

There are a few different reasons why the touch screen in a 2012 Toyota Camry would fail, and to narrow them down, more information is needed. For example, how exactly is the touchscreen "not working" Is it showing black Is it just not accepting Your touch gestures Is it accepting them, but the rest of the car isn't complying (like, speakers not playing music, etc) If the entire screen remains black, then You've most likely got a failed head unit / touch screen. There's not much that can be done for this, aside from total replacement. If You've got a blue screen, it would indicate a software failure that requires reflashing a proprietary system. Honestly, I don't even know if dealers can do this. In conclusion, Your issue can be as simple as a wiring issue, or as serious as full failure. Without more details, it's impossible to say.