Reverse Inhibitor Control

While the vehicle is moving forward, the PCM keeps shift solenoid valve E OFF. Shift valve E covers the line pressure port (3') leading to the servo valve reverse position. The servo valve cannot be shifted to reverse position, and hydraulic pressure is not applied to the 4th clutch. As a result, power is not transmitted to the reverse direction.

Fig 1: Hydraulic Flow Diagram (Driving In Reverse Gear In R)

Courtesy of AMERICAN HONDA MOTOR CO., INC.