Ice Possible
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The IPC illuminates the ICE POSSIBLE message in the 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.