Evaporator Low Ambient Protection
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
The refrigerant temperature at the evaporator air temperature sensor controls cycling of the compressor clutch to prevent freezing of the evaporator core. The compressor is disabled when the temperature goes below 3°C (37°F). The compressor is enabled when the temperature exceeds 4°C (39°F).