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 flowing from the ATF pump becomes the line pressure (1). The line pressure (1) is regulated by the regulator valve. The torque converter inlet pressure (92) enters (94) of the torque converter through the lock-up shift valve 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 as the manual valve stops line pressure (1).
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 the 1st-hold accumulator. The power is transmitted only during deceleration through the 1st-hold 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-1st-hold Clutch Pressure (16) -> 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 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. 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. Line pressure (1) also flows to throttle valve B.
NOTE: When used, "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 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 PCM. This valve stops 2nd clutch pressure and the power is not transmitted to the 2nd clutch. Line pressure (4) 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 to the 1-2 and 2-3 shift valves is the same as in 1st gear. As the speed of the vehicle reaches the prescribed value, the solenoid valve A is turned on by means of the PCM. 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. 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, 2-3 and 3-4 shift valves is the same as in the 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 fluid port leading to the 3rd clutch. Since the 3-4 shift valve is moved to the right to cover the fluid 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 - 3rd Clutch Pressure (30) -> 3rd Clutch. 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 (4TH GEAR)
The flow of fluid up to the 1-2, 2-3 and 3-4 shift valves is the same as in the 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 fluid 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 (41) -> Manual Valve - 4th Clutch Pressure (40) -> 4th Clutch.
CLUTCH PRESSURE
Hydraulic pressure also flows to the 1st clutch. However, no power is transmitted because of the one-way clutch as in 2nd and 3rd gear.
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 the N position. The fluid (1) from the ATF pump flows through the manual valve and becomes line pressure (3). It then flows through the 1-2 shift valve to the servo valve (3'), 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 speed 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.
REVERSE INHIBITOR CONTROL
When the R position is selected while the vehicle is moving forward at a speed over 6 mph (10 km/h), the PCM outputs 1st signal (A: OFF, B: ON), and the 1-2 shift valve is moved to the right side. The line pressure (3) is intercepted by the 1-2 shift valve; consequently, power is not transmitted as the 4th clutch and servo valve are not operated.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
P POSITION
The flow of fluid through the torque converter circuit is the same as in N position. The line pressure (1) becomes the 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 and the servo control valve, causing the shift fork shaft to be moved to the reverse position as in the R position. However, the hydraulic pressure is not supplied to the clutches. The power is not transmitted.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.