Ice Possible
WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The driver information center (DIC) displays the ICE POSSIBLE message when the outside air temperature drops below 2°C (36°F). When the temperature rises above 5.5°C (42°F), the ICE POSSIBLE message turns OFF. The DIC receives a GMLAN message indicating the outside air temperature from the body control module (BCM).