Reverse Shift Solenoid (SS) Valve Assembly (S5)
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Line (2) fluid passes through orifice #5 into the S5 signal (18) fluid circuit. The normally closed reverse SS valve assembly is OFF, causing fluid pressure to build-up in the S5 signal (18) fluid circuit.