My temp gauge work then stop work then stop what could cause that

I have the same car, and have the same issue. Every so often(EXTREMELY RANDOM) the temp guage will show nothing, the fans will kick on at 100%, and steering assist will be decreased. Mine started at around 50k miles.2 issues, 1st is the coolant temp sensor. If you pull it, it's cheaper to go ahead and change it. 2nd was the thermostat. Both are not difficult to do if have any sort of mechanical inclination. Parts are at the most 400, if you don't let a mechanic get you. She's been running like a champ since. (And id suggest flushing and changing the coolant at this time also). Best of luck to ya.