1st Gear: Powerflow

WARNING: This page is about a different car, the 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

In first gear, the forward clutch holds the front sun gear stationary.
The rear planetary carrier/center ring gear is held stationary by the low OWC and/or the low reverse (1, R) clutch.
The turbine shaft transfers torque to the center sun gear. The center sun gear transfers the torque to the center planetary carrier/front ring gear. The front ring gear transfers torque to the front planetary carrier/rear ring gear and the output hub to produce a ratio of 4.48.