Temp ran up to 210 degrees Put in new 185 thermostat temp still reads 200 why? on 2006 Pontiac Solstice

I knew to burp trapped air from motor. What else can be done could it be a bad sensor?

Asked by for the 2006 Pontiac Solstice
the computor sensors need 200 deg to function properly thats the design
1 more answer , 1 more comment
Is the cooling fan (radiator) coming on by 215F? If so , what's the problem? Normal operating temp is over 200F. Putting the wrong (to cold) thermostat in will create other problems.
the temp. never got that hot beforei did put same temp thermostat [185f] back in .