Pressure Control Solenoid A (PCA)
WARNING: This page is about a different car, the 2008 Ford Pickup, 2008 Ford F550 Super Duty, 2008 Ford F450 Super Duty, and 2008 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Pressure Control Solenoid A (PCA) is an inversely proportional 3-port device. The pressure output is inversely proportional to the applied direct current supplied through an electronically controlled driver, which varies the current between 0 and 1 amp from the PCM. The PCA solenoid controls the line pressure circuits.