alright, i had this happen, so there are two separate coolant temp sensors, one runs the fan and the other runs the block temp for the dash, not sure about a 2010 but my 08 has a single coolant sensor to the left of the alternator (if looking at the engine bay) when mine overheated it caused the coolant to boil and back up into the expansion tank and force steam out through the cap. terrifying but after thinking about throwing parts at it, plug it in and run a diagnostic that allows you to shut off the fan as it heats up. if its that sensor like mine that thing controls the overheat sensor on the dash and the fan from kicking on. hope this helps.