Page 457 of 1681
Description
LOC(,UP SlllFT VATVE
Lock-up System (cont'd)
No Lock-ug
The pressurized fluid regulated by the modulator works on both ends of the lock-up shift valve and on the left side ot
the lock-up control valve. Under this condition, the pressures working on both ends of the lock-up shift valve are equal.
the shift valve is moved to the right side by the tension of the valve spring alone. The tluid from the ATF pump will llow
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.
LOCX.UP CONTROI
LOCK.UP COITTFOT VATVE
MOOUTATOR PRESSURE
i
il
rl
I
IOCK IJP TIMING B VALVE
14-40
Page 458 of 1681

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
14-41
Page 459 of 1681

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
14-42
\
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
14-43
Page 461 of 1681
Description
LOCX UP CONTFOLSOLENOIO VAI.VE A
Lock-up System (cont'd)
Deceleration Lock-up
Lock-up Control Solenoid Valve A: ON Lock-up Control Solenoid Valve B: Duty Operation (ON e) OFF)
The TCM switches solenoid valve B ON and OFF rapidly under certain conditions. The slight lock-up and half lock-up
regions are maintained so as to lock the torque converter properly.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
tocK-uP col{TFoLSOTENOID VALV€ B
IOCK-UPCOITTROL VALVE
locK.uP trMrr{G B vAlv€
I 14-44I
\
\
u
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
Page 463 of 1681
Circuit Diagram
UNDER.HOOD FUSE/BELAY BOX
No.41 (100A1 No.47 (7.5A)
\'
WHT/BLU
423
LTGRN/BLK
I
GRNI/VHT
GRN/RED
GRN
GBN/BI"K
GRN/8LU
GRN/YET
LT GRN,M/HT
NoTE: I :To5v
T :1o 12v
14-46
\,
GAUGE ASSEMBTY
AiT GEAR POSITIONINOICATOR
To lzv lGl
rRANsMrssroN coNTRoL M.DULE rrcMr -fu
*> =
g
=.
I f- J:*
rrppr lo+rlo lru lrrpn tflt ti]t lrrezlerer
5VFEGULATOR
F- GRN/BLU
l--- GRN/YEL
l-- t"T GRN,aWHT
'v
Page 464 of 1681
'.J
THROTTLErcsm0NSENSOR
ENGINECOOLANTTEMPERATURESENSOR
WHT/BLKBLK/RED
820424
OBNREO/BLK
84
J
MAINSHAFI COUNTERSHAFISPEED SENSOR SPfED SENSOR
I SHIFT CONTROL I LOCK -UP CONTBOL
+135Eil,?1o'uo'u' 4i85El,o''P'uo'u'
TCM T6nninal locations
TCM -B l22P)Conn€ctor
VREF IATCHK IBASOSS IAFSA IAFSB IFAS ISCS
----T;- t-T-*
+.. | +.., I + ,+
l+ | J l/vt-l .i{-'1M-l L-{-lr^/t-lt't'/!-?
*\::
r--rr!\.1 -r!\./ rartsurssrot coNTFoL M'DULE tTcMr
ltEltn r' -rrt= t= t? t=
NMSG INC INCSG ISH A ISH B ILC A ILC B
576I101112578I10
151617,/1,/20251214,/1,/171920,/1,/J
TCM -A (26P1 Connector
14-47