Ice Possible
WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) illuminates the ICE POSSIBLE message in the driver information center (DIC) when the outside air temperature drops below 2.5°C (36.5°F). The IPC receives a class 2 message from the body control module (BCM) indicating the outside air temperature.