1-3 Clutch Regulator Valve
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
PCS 4 signal fluid, at the 1-3 clutch regulator valve, opposes 1-3 clutch regulator valve spring force and 13 clutch feedback fluid pressure to regulate line or auxiliary line pressure into the 13 clutch/A cooling feed circuit.