Power Transfer Unit (PTU)

PCM 

The PCM is the logic module for the AWD system. Multiple modules/system inputs are used for the AWD system to determine the percentage of torque to be transferred to the rear wheels.

The PTU is a gearbox that attaches to the transmission. The PTU directs power to the rear driveshaft and the Rear Drive Unit (RDU). For more information on the PTU, Refer to: Power Transfer Unit - Overview .