Acadia 2008 uae specification awd slt ,what is the problem here engine hot a/c off even the temperature needle is only75c and not going up or down fixed to the lowest like if the car off .acually i saw this message after i drive only7minutes without a/c at night normally(a/c was already off) .i want to know what is the problem her and how to fix it, the gauge needle is only 75 the lowest fixed and even i think the engine is ok .and i tried to put the a/c on after that but i coud not .