Transmission Cooling - Overview
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.
When the transmission fluid is below normal operating temperature, the transmission fluid flows from the transmission to the cooler bypass valve back to the transmission.
When the transmission fluid is at or above normal operating temperature, the transmission fluid cooler bypass valve opens allowing the transmission fluid to travel from the transmission through the oil-to-air transmission fluid cooler then back to the transmission. The oil-to-air transmission fluid cooler transfers heat from the transmission fluid to the outside air.