Lexus ES300 (1997 year). Manual — part 69

AUTOMATIC TRANSAXLE

OPERATION

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AX-3

2.

FUNCTION OF COMPONENTS

AX019-03

AUTOMATIC TRANSAXLE

OPERATION

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AX-4

Power from the engine transmitted to the input shaft via the torque converter clutch is then transmitted
to the planetary gears by the operation of the clutch.
By operation of the brake and one-way clutch, either the planetary carrier or the planetary sun gear
are immobilized, altering the speed of revolution of the planetary gear unit.
Shift change is carried out by altering the combination of clutch and brake operation.
Each clutch and brake operates by hydraulic pressure; gear position is decided according to the throttle
opening angle and vehicle speed, and shift change automatically occurs.
The conditions of operation for each gear position are shown on the following illustrations:

AUTOMATIC TRANSAXLE

OPERATION

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AX-5

3.

HYDRAULIC CONTROL SYSTEM
The hydraulic control system is composed of the oil pump, the valve body, the solenoid valves, the accu-
mulators, the clutches and brakes as well as the fluid passages which connect all of these components.
Based on the hydraulic pressure created by the oil pump, the hydraulic control system governs the hy-
draulic pressure acting on the torque converter clutch, clutches and brakes in accordance with the ve-
hicle driving conditions.
There are three solenoid valves on the valve body.
The No.1 and No.2 solenoid vales are turned on and off by signals from the ECM to operate the shift
valves and change the gear shift position.
The SL solenoid valve is operated by signals from the ECM to engage or disengage the lock-up clutch
of the torque converter clutch.
The SLN solenoid valve is operated by signals from the ECM to control the engagement speed and
reduce gear shift shock.

AX01A-0B

AUTOMATIC TRANSAXLE

COMPONENT PARTS REMOVAL

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AX-6

COMPONENT PARTS REMOVAL

COMPONENTS

AX02Q-02