Honda Civic. Manual — part 181

Fig. 50: Hydraulic Fuel Pressure Flow Diagram (D Position - Driving In 5th
Gear)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2 Position

The PCM controls the shift solenoid valves and the A/T clutch pressure control
solenoid valves. The conditions of the shift solenoid valves and the position of the
shift valves are as follows:

Shift solenoid valve A is turned ON, causing shift valve A to move to the left
side.

Shift solenoid valve B is turned OFF, keeping shift valve B on the right side.

Shift solenoid valve C is turned OFF, keeping shift valve C on the left side.

Line pressure travels up and through shift valve C (5D), through shift valve B (5G),
and then up to shift valve A (20) to become 2nd clutch pressure. The 2nd clutch is
engages by the 2nd clutch pressure.

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)

Fig. 51: Hydraulic Fuel Pressure Flow Diagram (2 Position)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

1 Position

The PCM controls the shift solenoid valves and the A/T clutch pressure control
solenoid valves. The conditions of the shift solenoid valves and the position of the
shift valves are as follows:

Shift solenoid valve A is turned OFF, keeping shift valve A on the right side.

Shift solenoid valve B is turned ON, causing shift valve B move to the left
side.

Shift solenoid valve C is turned OFF, keeping shift valve C on the right side.

Line pressure (1) from the manual valve flows to cut valve B, cut valve A, shift

NOTE:

When used, "left" or "right" indicates direction on the
hydraulic circuit.

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)

valve B, and becomes line pressure (5A) at the manual valve. Line pressure (5A)
passes through shift valve A, flows to shift valve C, and becomes 1st clutch
pressure (10). 1st clutch pressure (10) is applied to the 1st clutch, and the 1st clutch
is engaged.

Fig. 52: Hydraulic Fuel Pressure Flow Diagram (1 Position)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

R Position: Shifting to the R position from the P or N position

The manual valve is moved into the R position. This causes line pressure (1) to
become line pressure (1), (3), and (7) at the manual valve. The PCM turns shift
solenoid valves C and D ON, and shift solenoid valves A and B remain OFF. Shift
solenoid valve D pressure (SD) is applied to the left end of shift valve D, causing
shift valve D to move to the right side, uncovering the line pressure (3) port leading

NOTE:

When used, "left" or "right" indicates direction on the
hydraulic circuit.

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)

to the servo valve. Line pressure (3') from shift valve D flows to the servo valve,
and pushes the servo valve to the reverse position. The PCM controls A/T clutch
pressure control solenoid valve A to regulate A/T clutch pressure control solenoid
valve A pressure (55), and A/T clutch pressure control solenoid valve A pressure
(55) flows to the lock-up shift valve, shift valve B, the manual valve, the servo
valve, shift valve D, and cut valve A. A/T clutch pressure control solenoid valve A
pressure (3C) becomes 5th clutch pressure (50) at cut valve A. 5th clutch pressure
(50) is applied to the 5th clutch, and the 5th clutch is engaged by the A/T clutch
pressure control solenoid valve A pressure mode.

Fig. 53: Hydraulic Fuel Pressure Flow Diagram (R Position - Shifting To R
Position From P Or N Position)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

R Position: Driving in reverse gear

NOTE:

When used, "left" or "right" indicates direction on the
hydraulic circuit.

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)