Power Transfer Unit
WARNING: This page is about a different car, the 2018 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
The power transfer unit is a gearbox that attaches to the transmission and directs power to the rear driveshaft at all times. Engine coolant is directed to the power transfer unit to remove excess heat via an integrated cooler. The power transfer unit also contains a temperature sensor that is monitored by the PCM and AWD module. Refer to: Power Transfer Unit .