It can be the CUE unit itself, the HMI, or a loose connection. Only thing you could try yourself is the connections, rechecking the ones on the CUE and also on the HMI. These might be helpful for the HMI:
HMI Access / Glovebox Teardown
Looking to add Navtool or MVI module and looking for video on how to access the HMI module. Any help would be appreciated. I have a 13 ATS Performance
CUE and center cluster not working
Hi all, So I picked up my 2014 ATS last Monday, and by Friday evening the CUE system was entirely dead. Screen doesn't come on, no music, steering wheel controls don't light up. I drove it about 5 minutes to a restaurant, and when I came out to it after eating all was well. I went out later in...