1996 ACURA RL KA9 Service Repair Manual

Description
Hydraulic Flo w (cont'd )
Position
The flo w o f flui d throug h th e torqu e converte r circui t i s th e sam e a s in position .
Th e lin e pressur e (1 ) become s th e modulato r pressur e (6 ) a t th e modulato r valve , an d th e lin e pressur e (3 ) a t th e manua l
valve.
The modulato r pressur e (6 ) flow s t o th e righ t end s o f th e 1- 2 shif t valv e an d 2- 3 shif t valv e becaus e shif t solenoi d valv e A
i s turne d O N an d B is turne d OF F b y th e PCM , an d thos e valve s ar e move d to th e lef t side .
Th e lin e pressur e (3 ) flow s t o th e 1- 2 shif t valv e an d it become s th e revers e clutc h pressur e (50) . Th e revers e clutc h pres -
sur e (50 ) i s applie d to th e revers e clutch , an d th e revers e clutc h is engaged .
Revers e Inhibito r Contro l
When th e positio n i s selecte d whil e th e vehicl e i s movin g forwar d a t speed s ove r 6 mp h (1 0 km/h) , th e PC M output s th e
1s t signa l t o shif t solenoi d valve s A an d B ; shif t solenoi d valv e A is turne d OFF , shif t solenoi d valv e B is turne d ON . Th e 1 -
2 shif t valv e is move d to th e righ t sid e an d cover s th e por t t o sto p lin e pressur e (3 ) t o th e revers e clutch . Th e lin e pressur e
(3 ) i s no t applie d t o th e revers e clutch , an d th e revers e clutc h pressur e (50 ) i s no t applie d to th e revers e clutch , a s a result ,
powe r i s no t transmitte d i n th e revers e direction .
NOTE:
• Whe n used , "left " o r "right " indicate s directio n o n th e hydrauli c circuit .
• Th e hydrauli c circui t i s fo r '9 6 - '9 8 models . O n '9 9 - 0 1 models , th e 2n d accumulato r i s different .
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Position

The flow of fluid through the torque converter circuit is the same as in position.

The line pressure (1) is intercepted by the manual valve. Hydraulic pressure is not supplied to the clutches, and power is

not transmitted.

NOTE:

• When used, "left" or "right" indicates direction on the hydraulic circuit.

• The hydraulic circuit is for '96 - '98 models. On '99 - 01 models, the 2nd accumulator is different.ProCarManuals.com

Lock-up System

Lock-up Clutch

1. Operation (clutch on)

With the lock-up clutch on, the fluid in the chamber between the torque converter cover and the lock-up piston is drained

off, and the converter fluid exerts pressure through the piston against the torque converter cover. As a result, the converter

turbine is locked to the converter cover. The effect is to bypass the converter, thereby placing the vehicle in direct drive.

LOCK-UP PISTON

TORQUE CONVERTER

COVER
DAMPER SPRING

TURBINE

2. Operation (clutch off)

With the lock-up clutch off, the fluid flows in the reverse of CLUTCH ON. As a result, the lock-up piston moves away from

the converter cover, and the torque converter lock-up is released.

TORQUE CONVERTER

COVER
MAINSHAFT
DescriptionProCarManuals.com

In position in 2nd, 3rd and 4th, and position in 3rd, pressurized fluid is drained from the back of the torque converter

through a passage, causing the lock-up piston to be held against the torque converter cover. As this takes place, the main-

shaft rotates at the same speed as the engine crankshaft. Together with hydraulic control, the PCM optimizes the timing of

the lock-up system. Under certain conditions, the lock-up clutch is applied during deceleration in 3rd and 4th gear.

The lock-up system controls the range of lock-up according to torque converter clutch (lock-up control) solenoid valves A

and B, and the throttle valve. When torque converter clutch solenoid valves A and B activate, modulator pressure

changes. Torque converter clutch solenoid valves A and B are mounted on the torque converter housing, and are con-

trolled by the PCM.

NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.ProCarManuals.com

Description

Lock-up System (cont'd)

No Lock-up

The pressurized fluid regulated by the modulator works on both ends of the lock-up shift valve and on the left side of the

lock-up control valve. Under this condition, the pressures working on both ends of the lock-up shift valve are equal, and

the shift valve is moved to the right side by the tension of the valve spring alone. The fluid from the pump will flow

through the left side of the lock-up clutch to the torque converter; that is, the lock-up clutch is in OFF condition.

NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.ProCarManuals.com