Four Wheel Drive (4WD) Systems: Overview
WARNING: This page is about a different car, the 2013 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The AWD system is always active and only requires the operator to select terrain. Torque from the engine is transferred through the transaxle to the PTU . The PTU is a mechanical device attached to the transaxle. This torque is transferred through the driveshaft to the rear axle, which drives the rear halfshafts. The driver can optimize the AWD system by setting the ATCM switch for the correct terrain.