02 Grand Prix Outside Air Temp. Rear View Mirror readings off!!!

The temp on my rear view mirror inside the car is way off when it's 10 degrees out side it reads -27 degrees etc... Is there a sensor or modual to replace or do i have to replace the whole mirror assy.??? Please help

Thanks

There is an ambient air temp sensor mounted behind the grill in the front of the car that reads the temp for the mirror (and the auto climate control if equipped). GM part #10248414. Dealer retail is only $9.43.

Thank you very much!!! :)