High Transmission Fluid Level
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.
A transmission fluid level that is too high may cause the transmission fluid to become aerated due to the churning action of the rotating internal parts. This will cause erratic control pressure, foaming, loss of transmission fluid from the vent tube and possible transmission malfunction and/or damage.