Heat Protection Power Transfer Unit
WARNING: This page is about a different car, the 2015 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
During excessive use or trailer towing the AWD system may implement a heat protection mode to protect the power transfer unit from damage. The AWD system will reduce commanded torque only to situation deemed critical for minimal function. Once the maximum temperature limit is reached, then FWD only is commanded.