Page 445 of 1681

Description
Hydraulic Flow
G€n6.al Chart of Hydraulic Pr6sure
ATF Pump - Regulator Valve
Distribution of Hydraulic Pressuro
Line Pressure -----r- Modulator Pressure
F-- Thronle B PressureL Clutch Pressure
Toroue Convener Pressure
Lubrication Pressure
. Regulator Valve ----; Torque Converter Prossure
f- Lubricaiion PrassureL To Regulate Line Pressure
Manual Valve - To Select Line Pressure - Clutch Pressure
. Modulator Valve Modulator Pressure ---- --I----- Shift Control Solenoid ValvosL- Lock-uD Control Solenoid Valves
. 1-2 Shift Valve -----l
. 2-3 Shift Valve ----f- Clutch Pressure. 3-4 Shift Valve ----------r
. Throttle Valve - Throttle B Pressure
NO,DESCRIPTION OF PRESSURENO.DESCRIPTION OF PR€SSURENO.DESCRIPTION OF PRESSURE
1LINE6C
MODULATOR(LOCK.UP CONTROL
SOLENOID VALVE A)
55THROTTLE B
LINE6D
MODULATOR(LOCK-UP CONTROL
SOLENOID VALVE B)
56THROTTLE B
LINEaLINETHROTTLE B
LINE101ST CLUTCH5dTHROTTLE B
LINE151ST-HOLD CLUTCH90TOROUE CONVERTER
4LINElST.HOLD CLUTCH91TOROUE CONVERTER
LINE18LINE92TOROUE CONVERTER
5LINE202ND CLUTCH93ATF COOLER
LINE212ND CLUTCH94TOROUE CONVERTER
5'LINE25LINELUBRICATION
6MODULATOR303RD CLUTCH96TOROUE CONVERTER
MODULATOR313RD CLUTCH97TOBOUE CONVERTER
64MODULATOR(SHIN CONTROLSOLENOIO VALVE A)404TH CLUTCHooSUCTION
6BMODULATOR(SHIFT CONTROT SOLENOID VATVE B)414TH CLUTCHXBLEED
Page 447 of 1681
Description
Hydraulic Flow (cont'dl
L! l Position
The line pressure ( 1 ) becomes line pressure (4) at the manual valve and passes to the 1st clutch and 1 st accumulator.
Then line pressure (4) llows through the 1st-hold clutch and 1st-hold accumulator.
Fluid flows bv wav of:- Line Pressure (4) - 1-2 Shift Valve - 2-3 Shitt Valve - 3rd Clutch Pressure (31) -- 3-4 Shift Valve - 4th Clutch
Pressure (41) - Manual Valve - lst-hold Clutch Pressure (15) - lsfhold Clutch
The modulator pressure (6) is supplied to the 1-2 and 2-3 shift valves.
The lane Dressure (1) also flows to the throttle valve B.
NOTE: When used, "left" or "right" indicates direction on the hydraulic ci.cuit.
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Description
Hydraulic Flow {cont'dl
l ll or &j Position
1. lst Geal
The flow of fluid through the torque converter circuit is the same as in lll postion.
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 l-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 (4) also flows to the servo valve and line pressure (l ) also flows to throttle valve B.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
fr
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Page 456 of 1681

In E position in 2nd, 3rd and 4th, and E position in 3rd, pressurized fluid is drained from rhe back of the torque con-
verter through a fluid passage, causing the lock-up piston to be held against the torque converter cover. As this takes
place, the mainshaft rotates at the same speed as the engine crankshatt. Together with hydraulic control, the TCM op-
timized 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 lock-up control solenoid valves A and B, and the throttle
valve B. When lock-up control solenoid valves A and B activate, modulator pressure changes. Lock-up control solenoid
valves A and B are mounted on the torque converter housing. and are controlled by the TCM.
LOCK,UP CONTROL
LOCT.UP SHIfT VALVE
AlF COOIER
tocK uP coNTno! valvE
Solenoid valve
L*r""r "o.Jtio" \B
Lock'up OFFOFFOFF
Lock-up, slightONOFF
Lock-up, halfONON
Lock-up, fullONON
LOCK-Updu.ing decelerationONDuty operationOFF - ON
IOCK UP TIMING B VATVE
(cont'd)
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IPartial Lock-up
Lock-uo Control Solenoid Valve A: ONLock-uD Control Solenoid Valve B: OFF
The TCM switches solenoid valve A ON to release modulator Dressure in the left cavity of the lock-up shift valve.
Modulator pressure in the right cavity of the lock-up shift valve overcomes the spring force, 8nd the lock-up shift valve is
moved to the left side,
Modulator pressure is separated into the two passages:
Torque Converter Inner Pressure: enters into right side to engage lock-up clutch,
Torque Converter Back Pressure: enters into left side to disengage lock-up clutch.
Back prassure {F2) is regulated by the lock-up control valve whereas the position of the lock-up timing B valve is deter-
mined by the throttle B pressure, tension of the valve spring, and pressure regulated by the modulator. Also the position
of the lock-up control valve is determined by the back prossure of the lock-up control valve and torque converter pressure
regulated by the check valve. With lock-up control solenoid valve B kept OFF. modulator pressure is maintained in the left
end of the lock-up control valve; in other words, the lock-up control valve is moved slightly to the left side. This slight
movement of the lock-up control valve causes the back pressure to be lowered slightly, resulting in partial lock-up.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
LOCK.UP GO TNOLSOLENOIO VAIVE A
TOCK-UP SHIFT VAIVELOCI( UP COI{TROL VAIVE
T
LOC(,UP IM TG g VALV€
MODULATOB PNESSUFE
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Description
I,OCK UP SHIFT VALVE
Lock-up System (cont'dl
Halt Lock-up
Lock-up Control Solenoid Valve A: ONLock-up Control Solenoid Valve B: ON
Modulator pressure is released by solenoid valve B. causing modulator pressure in the left cavity of the lock-up control
valve to lower.
Also modulator pressure in the left cavity of lock-up timing B valve is low. However, throttle B pressure is still low so lock-
up timing B valve is kept on the right side by spring force.
With lock-up control solenoid valve B turned ON, the lock-up control valve is moved somewhat to the left side, causing
back pressure (F2) to lower. This allows a greater amount of fluid (F1) to work on the lock-up clutch to engage the clutch.
Back pressure (F2) which still exists, prevents the clutch from engaging fully.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
LOCK.UP COI\ITBOL
THROITIE B PRESSUREIOCX UP COIITROL VALVE
MODULATOR PNESSURE
TOCK UP TIMING B VALVE
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\
t
{
Page 460 of 1681
'Full Lock-up
Lock-up Control Solenoid Valve A: ONLock-uD Contorl Solenoid Valve B:ON
When the vehicle speed further increases, throttle B pressure is increased in accordance with the throttle opening.
The lock-up timing B valve overcomes spring force and moves to the left side. Also, this valve closes the port leading to
the torque convener check valve.
Under this condition, throttle B pressure working on the right end of the lock-up control valve becomes greater than that
on the left end (modulator pressure in the left end has already been released by the solenoid valve B); the lock-up control
valve is moved to the left. As this happens, torque converter back pressure is fully released, causing the lock-up clutch to
be tully engaged.
NOTE: When used, "lelt" or "right" indicates direction on the hydraulic circuit.
LOC( UP CONiBOT
LOCK UP SHIFT VAIVE
MODULATOR PBESSURE
ATF COOLER
I
IOC( UP TIMING B VALVE
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Page 462 of 1681
Component Locations
"/,4
'JJ-N
{7v
A0t
\ /
t
AUTOMATIC TRANSAXLE IAiTIGEAR POSITION SWITCH
VEHICLE SPEEDSENSOR {VSSt
COUNTERSHAFTSPEED SENSORMAINSHAFT SPEEDSENSORTHROTTLE POSITIOT{ {TPI
e
SHIFT CONTROLSOLENOID VALVE A/BASSEMBLY
I
- ::::i ---l
1445