#4 Ball Check Valve
WARNING: This page is about a different car, the 2008 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
PS5 fluid pressure seats the #4 ball check valve against the 456 clutch fluid circuit. PS5 fluid is then directed into the CSV2 latch fluid circuit and routed to the clutch select valve 2. CSV2 latch fluid combines with clutch select valve 2 spring force and holds the valve in this position during all 6 forward gear ranges.