I have a 2008 Pontiac GT, regularly maintained and all runs fine. Just one problem that has popped up over the last few weeks since the warmer weather has arrived: On the computer readout in the dash, if the “Coolant” display shows a temperature (say, 83C or what have you), then the AC works. However, much of the time the Coolant reading shows “—” (3 blank dashes), and the AC does not work. It’s still been quite cool around here (Toronto area) so I haven’t needed the AC much but it’s heating up and I’d sure love to take care of this if possible. Thanks for any help!