Reverse Inhibitor Control
WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
When R is selected while the vehicle is moving forward at speeds over 6 mph (10 km/h), the PCM commands shift solenoid valve D to remain OFF so that shift solenoid valve D pressure (SD) is not applied to the reverse control valve Line pressure (3) stops at the reverse control valve, and is not applied to the servo valve No power is transmitted to the reverse direction
NOTE:
When used, "left" or "right" indicates direction on the hydraulic circuit