says AC turned off high engine temp as soon as I turned the car on yesterda morn

What is your question?

Fan runs after car shut off yesterday .The temp needle stood on C yesterday and today. Check engine light came on this morning. Fan did not run after I shut the car off this morning. Diagnostic says cap loose. I adjusted the gas cap and tightened it and started the car. Made it run for 2 minutes then shut it off. Fan ran for 3 minutes. Would this be a sensor? No leaks from car. Engine sounded weird yesterday like it's not getting the gas to stay on. It did not shut off maybe air got in there?

What makes this problem better or worse?

gas cap loose - will the problem go away ?

How long has your 2013 Cadillac ATS had this problem?

since yesterday