Temperature bars don’t change ?

Ok let me start by saying nothing was / is wrong with the bike .
It was a loose nut behind the bars causing the issue. I had the wrong screen up and have been looking at my maintenance schedule . The bars on both screens look the same except for the wrench or thermometer at the top. Problem solved by riding to my local shop and having them “ fix” it for me . I gotta say I felt rather dumb at that point but am happy the mystery is solved
 
loose nut behind the bars of what?