M18

Hi guys. I just recently acquired a 2007 523i LCI Manual some 2 weeks ago. Car has been running perfectly fine. Its just that today my AC wouldn't blow cold air like it used to and I got a "Engine too Hot..Drive Moderately" msg on the idrive. I got the msg after a 10 minute short drive as soon as i parked in the garage. One thing that I've noticed is that the big fan near the radiator is not turning when the AC is on. How should I go about diagnosing this problem? And another thing, how hot is this engine designed to run on? After accessing the hidden OBC settings, I got a max temp of 107? is that too much for this car?