Automatic Transmission Fluid Warming Valve
WARNING: This page is about a different car, the 2018 Land Rover Discovery Sport. However, it is still accessible from the selected car via links, so may be relevant.
Regarding the operation of the Automatic Transmission Fluid (ATF) warming valve the following three phases can be differentiated:
Warm-up phase - Hot engine coolant from the thermostatic valve of the ATF cooler is directed to the ATF cooler. This provides a reduced ATF warm-up time.
Temperature control phase - Hot engine coolant from the thermostatic valve of the ATF cooler and cold engine coolant coming from the radiator are mixed. This provides an accurate control to maintain the ATF at the desired operation temperature
Cooling phase - Cold engine coolant from the radiator is directed to the ATF cooler to provide the maximum ATF cooling capability.