Transmission Fluid Temperature (TFT) Sensor
WARNING: This page is about a different car, the 2006 Mercury Montego and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The transmission fluid temperature sensor, which is integrated within the transmission wiring, is installed on the front of the valve body. It directs the fluid temperature within the hydraulic pressure control circuit and transmits a signal based on that temperature to the TCM. Through this it controls gear shift, lockup and slip in response to changes in fluid temperature for smooth shifting across wide fluid temperature zones.