Manual Valve
WARNING: This page is about a different car, the 2004 Pontiac Sunfire, 2004 Chevrolet Classic, and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The gear selector lever mechanically controls the manual valve, which is in Park (P) position. The manual valve directs line pressure into the PRND4 and the PRN fluid circuits.