When shifting to R, the PCM turns shift solenoid valves B and E ON, and A, C, and D are turned OFF. Shift solenoid valve B pressure (SB) is applied to the right side of shift valve B, and shift valve B is moved to the left side. Shift solenoid valve E pressure (SE) is applied to the left side of shift valve E, and shift valve E is moved to the right side. Line pressure (1) changes to (3) at the manual valve, and flows to the servo valve via shift valve E. The servo valve is moved to the reverse range position. Movement of shift valves B and E, and the servo valve creates 4th clutch pressure line between the 4th clutch and A/T clutch pressure control solenoid valve A. 4th clutch pressure (40) is applied to the 4th clutch, and the 4th clutch is engaged gently.

NOTE: When used, ‘‘left'' or ‘‘right'' indicates direction on the hydraulic circuit.

When R is selected while the vehicle is moving forward, the PCM commands shift solenoid valve A to turn OFF, and E to remain OFF. Shift solenoid valve A pressure (SA) is not applied to shift valve A so that line pressure (3A) is not applied to the servo valve. Also shift solenoid valve E pressure (SE) is not applied to shift valve E so that line pressure (3') is not applied to the servo valve. The servo valve cannot be shifted to the reverse position, and hydraulic pressure is not applied to the 4th clutch from the servo valve for reverse; as a result, power is not transmitted to the reverse direction.

NOTE: When used, ‘‘left'' or ‘‘right'' indicates direction on the hydraulic circuit.