Torque Converter Clutch (TCC) Solenoid
WARNING: This page is about a different car, the 2012 Ford F550 Super Duty and 2012 Ford F450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The TCC solenoid is a directly proportional VFS. The pressure output of this 3-port device is proportional to the applied direct current supplied from the PCM through an electronically controlled driver which varies the current between 0 and 1 amp.