Manual Valve (404)
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2006 Saturn Relay, 2006 Pontiac Montana SV6, 2006 Pontiac Grand Prix, 2006 Pontiac G6, and 2006 Chevrolet Uplander. However, it is still accessible from the selected car via links, so may be relevant.
The manual valve is moved to the NEUTRAL position and blocks line pressure from entering the Reverse fluid circuit. The reverse fluid circuit is opened to an exhaust at the manual valve.