Honda Civic. Manual — part 178

3A

Line or A/T clutch
pressure control
solenoid valve A

55

A/T clutch
pressure control
solenoid valve A

3B

Line or A/T clutch
pressure control
solenoid valve A

55'

A/T clutch
pressure control
solenoid valve A

3C

Line or A/T clutch
pressure control
solenoid valve A

56

A/T clutch
pressure control
solenoid valve B

5A

Line or A/T clutch
pressure control
solenoid valve A

57

A/T clutch
pressure control
solenoid valve C

5B

Line, A/T clutch
pressure control
solenoid valve A,
or C

90

Torque converter

5C

A/T clutch
pressure control
solenoid valve C

91

Torque converter

5D

Line or A/T clutch
pressure control
solenoid valve A

92

Torque converter

5E

Line or A/T clutch
pressure control
solenoid valve B

93

ATF cooler

5F

A/T clutch
pressure control
solenoid valve B

94

Torque converter

5G

Line, A/T clutch
pressure control
solenoid valve A,
or B

95

Lubrication

5H

A/T clutch
pressure control

96

Torque converter

2008 Honda Civic LX

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

N Position

The PCM controls the shift solenoid valves. The conditions of the shift solenoid
valves and positions of the shift valve are as follows:

Shift solenoid valve A is turned OFF, shift valve A remains on the right side,
and cut valve A remains on the left side.

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

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

Line pressure (1) passes through the manual valve and stops at cut valve B. Line
pressure (1) also flows to shift solenoid valves, and A/T clutch pressure control
solenoid valve A. Under this condition, hydraulic pressure is not applied to the
clutches.

solenoid valve B

5J

A/T clutch
pressure control
solenoid valve C

97

Torque converter

5K

A/T clutch
pressure control
solenoid valve C

99

Suction

5L

A/T clutch
pressure control
solenoid valve C

X

Drain

5M

A/T clutch
pressure control
solenoid valve B

HX

High position drain

5R

A/T clutch
pressure control
solenoid valve C

AX

Air drain

NOTE:

When used, "left" or "right" indicates direction on the

2008 Honda Civic LX

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

Fig. 40: Hydraulic Fuel Pressure Flow Diagram (N Position)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

D Position: 1st gear shifting from the N position

The shift solenoid valves and the shift valves remain the same position when
shifting from D to N. The PCM actuates A/T clutch pressure control solenoid valve
A to regulate the line pressure. Line pressure (1) becomes A/T clutch pressure
control solenoid valve A pressure (55), and A/T clutch pressure control solenoid
valve A pressure flows to the lock-up shift valve, shift valve B, the manual valve,
and shift valve A. Also solenoid valve A pressure becomes 1st clutch pressure (10)
at shift valve C, and 1st clutch pressure (10) flows to the 1st clutch. The 1st clutch
is engaged by A/T clutch pressure control solenoid valve A pressure mode when
shifting to D from N.

hydraulic circuit.

NOTE:

When used, "left" or "right" indicates direction on the

2008 Honda Civic LX

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

Fig. 41: Hydraulic Fuel Pressure Flow Diagram (D Position - 1st Gear Shifting
From N Position)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

D Position: Driving in 1st gear

The PCM turns shift solenoid valve B ON, and shift solenoid valves A and C
remain OFF. Shift solenoid valve B pressure (SB) is applied to the right side of shift
valve B. Shift valve B then moves to the left side, causing the line pressure port
leading to the 1st clutch to be uncovered, and the A/T clutch pressure control
solenoid valve A pressure port to be covered. Line pressure (1B) passed through
shift valve B flows to the manual valve, shift valve A, and shift valve C, and
becomes 1st clutch pressure (10). 1st clutch pressure is applied to the 1st clutch, and
the 1st clutch is engaged by the line pressure mode.

hydraulic circuit.

NOTE:

When used, "left" or "right" indicates direction on the

2008 Honda Civic LX

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