Gentex 261 Mirror Temp Display?

I have a Gentex GNTX261 OnStar mirror from a 02 LeSabre that I am trying to get working in my project truck. It has a single line display that currently displays the compass. I am trying to find out if it is possible for this mirror to display the outside temperature instead. I notice when the mirror powers up, I can see *F and *C lights on the right side of the display. I hooked up my ambient air temp sensor to pins 6 and 7 on the connector.

Is there some way on this mirror to switch between compass and temp? The only buttons I have available is the power button, a button with a white circle, the blue onstar button, and the red emergency button. I've tried holding the buttons, the only button that does something when you hold it is power (for the compass settings).

Thanks,

Greg