Automatic Transmission/Transaxle
HYDRAULIC FLOW
[N] Position
As the engine turns, the ATF pump also starts to operate. Automatic transmission fluid (ATF) is drawn from (99) and discharged into (1). Then, ATF pressure is controlled by the regulator valve and becomes line pressure (1). The torque converter inlet pressure (92) enters (94) of torque converter through the orifice and discharges into (90). The torque converter check valve prevents the torque converter pressure from rising. Under this condition, the hydraulic pressure is not applied to the clutches.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
[1] Position
The line pressure (1) becomes line pressure (4) at the manual valve and passes to the 1st clutch and 1st accumulator. Then line pressure (4) flows through the 1st-hold clutch and 1st-hold accumulator.
Fluid flows by way of:
-Line Pressure (4) -> 1-2 Shift Valve -> 2-3 Shift Valve - 3rd Clutch Pressure (31) -> 3-4 Shift Valve - 4th Clutch Pressure (41) -> Manual Valve - 1st-hold Clutch Pressure (15) -> 1st-hold Clutch
The modulator pressure (6) is supplied to the 1-2 and 2-3 shift valves. The line pressure (1) also flows to the throttle valve B.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
[2] Position
The line pressure (1) becomes line pressure (4) as it passes through the manual valve. It then goes through line (20) to the 2nd clutch via the 1-2 and 2-3 shift valves. Also, line pressure (1) goes to the modulator valve through the filter and becomes the modulator pressure (6). Modulator pressure (6) is not supplied to the 1-2, 2-3 and 3-4 shift valves because the shift control solenoid valves A and B are turned ON by the TCM.
NOTE: When use, "left" or "right" indicates direction on the hydraulic circuit.
[D3] or [D4] Position
1. 1st Gear
The flow of fluid through the torque converter circuit is the same as in N position.
The line pressure (1) becomes line pressure (4) and it becomes the 1st clutch pressure (10). The 1st clutch pressure is applied to the 1st clutch and 1st accumulator; consequently, the vehicle will move as the engine power is transmitted. The line pressure (1) becomes the modulator pressure (6) by the modulator valve and travels to 1-2 and 3-4 shift valves. The 1-2 shift valve is moved to the right side because the shift control solenoid valve A is turned OFF and B is turned ON by the TCM. This valve stops 2nd clutch pressure and power is not transmitted to the 2nd clutch. Line pressure M also flows to the servo valve and line pressure (1) also flows to throttle valve B.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
2. 2nd Gear
The flow of fluid up the 1-2 shift valve is the same as in 1st gear. As the speed of the vehicle reaches the prescribed value, the shift control solenoid valve A is turned ON by means of the TCM. As a result, the 1-2 shift valve is moved to the left and uncovers the port leading to the 2nd clutch; the 2nd clutch is engaged.
Fluid flows by way of:
- Line pressure (4) -> 1-2 Shift Valve -> 2-3 Shift Valve - 2nd Clutch Pressure (21) -> 2nd Clutch
The hydraulic pressure also flows to the 1st clutch. However, no power is transmitted because of the one-way clutch.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
3. 3rd Gear
The flow of fluid up to the 1-2 and 2-3 shift valve is the same as in 2nd gear. As the speed of the vehicle reaches the prescribed value, the shift control solenoid valve B is turned OFF (shift control solenoid valve A remains ON). The 2-3 shift valve is then moved to the left, uncovering the port leading to the 3rd clutch. Since the 3-4 shift valve is moved to the right to cover the port to the 4th clutch, the 3rd clutch is turned on.
Fluid flows by way of:
- Line pressure (4) -> 1-2 Shift Valve -> 2-3 Shift Valve - 3rd Clutch Pressure (31) -> 3- 4 Shift Valve (not controlled) - 3rd Clutch Pressure (30) -> 3rd Clutch
The hydraulic pressure also flows to the 1st clutch. However, no power is transmitted because of the one-way clutch as in the 2nd gear.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
[D4] Position
4. 4th Gear
The flow of fluid up to the 1-2, 2-3 and 3-4 shift valves is the same as in 3rd gear. As the speed of the vehicle reaches the prescribed value, the shift control solenoid valve A is turned OFF (shift control solenoid valve B remains OFF). As this takes place, 3-4 shift valve is moved to the left and uncovers the port leading to the 4th clutch. Since the 1-2 and 2-3 shift valves are kept on the left side, the fluid flows through the 4th clutch; the power is transmitted through the 4th clutch.
Fluid flows by way of:
- Line pressure (4) ->, 1-2 Shift Valve -> 2-3 Shift Valve - 3rd Clutch Pressure (31) -> 3-4 Shift Valve - 4th Clutch pressure (41) -> Manual Valve - 4th Clutch Pressure (40) -> 4th Clutch
The hydraulic pressure also flows to the 1st clutch. However, no power is transmitted because of the one-way clutch as in 2nd and 3rd gears.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
[R] Position
The flow of fluid through the torque converter circuit is the same as in [N] position. The line pressure (1) flows through the manual valve and becomes line pressure (3). It then flows through the 1-2 shift valve to the servo valve via the servo control valve, causing the shift fork shaft to be moved in the reverse direction.
Under this condition, the shift control solenoid valve A is turned ON whereas the valve B is turned OFF as in 3rd gear in [D4], or [D3] position. As a result, the 1-2 shift valve is also moved to the left. The fluid (3') will flow through the servo valve and manual valve to the 4th clutch; power is transmitted through the 4th clutch.
[P] Position
The flow of fluid through the torque converter circuit is the same as in [N] position. The line pressure (1) becomes line pressure (3) as it passes through the manual valve. Then line pressure (3) flows through the 1-2 shift valve to the servo valve via the servo control valve, causing the shift fork shaft to be moved to the reverse position as in R position. However, the hydraulic pressure is not supplied to the clutches. Power is not transmitted.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.