Hydraulic Flow

Distribution of Hydraulic Pressure

As the engine turns, the ATF pump starts to operate. Automatic transmission fluid (ATF) is drawn through the ATF strainer (filter) and discharged into the hydraulic circuit. Then, ATF flowing from the ATF pump becomes line pressure that is regulated by the regulator valve. Torque converter pressure from the regulator valve enters the torque converter through the lock-up shift valve, and it is discharged from the torque converter. The torque converter check valve prevents torque converter pressure from rising.
The PCM turns the shift solenoid valves ON and OFF. The shift solenoid valve intercepts line pressure from the ATF pump via the manual valve when the shift solenoid valve is OFF. When the shift solenoid valve is turned ON by the PCM, line pressure changes to shift solenoid valve pressure at the shift solenoid valve, then the shift solenoid valve pressure flows to the shift valve. Applying shift solenoid pressure to the shift valves moves the position of the shift valve, and switches the port of the hydraulic circuit. The PCM also controls A/T clutch pressure control solenoid valves A, B, and C. The A/T clutch pressure control solenoid valves regulate hydraulic pressure, and applies the pressure to the clutches to engage smoothly. The clutches receive optimum clutch pressure which is regulated by the A/T clutch pressure control solenoid valves for comfortable driving and shifting under all conditions.

Hydraulic pressure at the port for use in the hydraulic circuit

Port No.
Hydraulic Pressure
Port No.
Hydraulic Pressure
1
Line
SB
Shift solenoid valve B
3
Line
SC
Shift solenoid valve C
 3'
Line
SD
Shift solenoid valve D
4
Line
SE
Shift solenoid valve E
 4'
Line
10
1st clutch
  4''
Line
20
2nd clutch
7
Line
30
3rd clutch
1A
Line or A/T clutch pressure control solenoid valve A
40
4th clutch
1B
Line
50
5th clutch
3A
Line
55
A/T clutch pressure control solenoid valve A
3B
Line
 55'
A/T clutch pressure control solenoid valve A
3C
Line
56
A/T clutch pressure control solenoid valve B
5A
Line
57
A/T clutch pressure control solenoid valve C
5B
Line
90
Torque converter
5C
Line
91
Torque converter
5D
Line
92
Torque converter
5E
Line or A/T clutch pressure control solenoid valve B
93
ATF cooler
5F
Line or A/T clutch pressure control solenoid valve A or B
94
Torque converter
5G
A/T clutch pressure control solenoid valve B
95
Lubrication
5H
A/T clutch pressure control solenoid valve C
96
Torque converter
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
5N
A/T clutch pressure control solenoid valve C
HX
High position drain
SA
Shift solenoid valve A
AX
Air drain


N Position

The PCM controls the shift solenoid valves. The conditions of the shift solenoid valves and the positions of the shift valves are as follows:
  • Shift solenoid valve A: OFF, and shift valve A remains on the right side
  • Shift solenoid valve B: ON, and shift valve B moves to the left side
  • Shift solenoid valve C: ON, and shift valve C moves to the left side
  • Shift solenoid valve D: OFF, and shift valve D remains on the left side
  • Shift solenoid valve E: OFF, and shift valve E remains on the left side
Line pressure (1) flows to the shift solenoid valves and A/T clutch pressure control solenoid valve A. Under this condition, hydraulic pressure is not applied to the clutches.
NOTE: When used, ‘‘left'' or ‘‘right'' indicates direction on the hydraulic circuit.