Hey did you ever find a fix for this? I too have a 2014 sonic SAME EXACT issue!I just purchased a 2014 Chevy Sonic Saturday. My touchscreen is not working. It comes on and boots completely fine, but it doesnt work as a touchscreen! I tried using my finger, nail, a stylus, nothing works. I can see all of the options but can't use them. I can only control the stereo from the steering wheel controls. I also contacted the dealership and was told it would be $600 for a "screen repair". I'm hoping maybe it will be a fuse issue as well? Any suggestions?