Page 692 of 2189

Description
Electronic Control System (cont'd)
Shift Control
The PCM instantaneously determines which gear should be selected by various signals sent from sensors, and actuatesthe shift control solenoid valves A and B to control shifting. Also. a Grade Logic Control System has been adopted to con-trol shifting in E position while the vehicle is ascending or descending a slope, or reducing speed.
PoshionGearShift Control Solenoid
Vslve A
Shift Control Solenoid
Valve B
8,tr
1stOFFON
2ndONON
3rdONOFF
E4thOFFOFF
tr2ndONON
E-ReverseONOFF
*See page 14-31 for reverse inhibitor control description.
Lock-up Control
From sensor input signals, the PCM determines whether to turn the lock-up ON or OFF, and activates lock-up controlsolenoid valve A and/or B accordingly. The combination of driving signals to lock-up control solenoid valves A and B andthe linear solenoid pressure is shown in the table below.
Lock-up ConditionsLock-up Control
Solenoid Valvo A
Lock-up Control
Solenoid Valve B
Linoar Solonoid
Prggguro
Lock-up OFFOFFOFFHigh
Lock-up, HalfONDuty operation
OFF * ONLow
Lock-up, FullONONHigh
LOCK-Up
during decelerationONDuty operation
OFF - ON
a
14-14
Page 697 of 2189

Hydraulic Control
The hydraulic control system is controlled by the ATF pump, valves, accumulators, and electronically controlled solenoids'
TheATFpUmpisdrivenbysp||nesontheendofthetorqueconverterWhichisattachedtotheengine.F|uidfromtheATF
pumpf|owsthroughtheregu|atorva|vetomajntainspecifiedpressurethroughthemainva|vebodytothemanuaIva|ve'
directingpressuretoeachofthec|utches.Theva|vebodyinc|udesthemainvaivebody,theregu|atorvalvebody,the
|ock-upva|vebody,thesecondaryVa|vebody,theservobody,theIinearso|enoid,theshiftcontro|so|enoidva|velVB
assembly, and the lock up control solenoid valve A/B assembly. The shift control solenoid valve Ay'B assembly and the lin-
ear solenoid are bolted on the outside of the transmission housing. The lock-up control solenoid valve A,/B assembly is
bolted on the outside of the torque converter housing
SHIFT CONTROLSOLENOIO VALVE A/8
ASSEMBLY
LINEAR SOLENOID
SERVO BOOY
REGULATORVALVE BODY
VALVE
VALVE BOOY
(cont'd)
CONTROLSOLENOID VALVE A/BASSEMBLY
ATF PUMP GEARS
14-19
Page 702 of 2189

Description
Hydraulic Flow
General Chart ol Hydraulic PressureATF Pump- pegurator varve -_l- Line pressure -f- Modurator pressure - Linear sorenoid
| -Clutch pressure
-Torque Converter pressure
t-Lubrication Pressure
Distribution of Hydraulic Pressur€. Regulator Valve -]- Torque Converter pressure
F_ Lubrication pressure
i- To regulate Line pressure
. Manual valve _ To select Line pressure _ clutch pressure
' Modulator Valve i/odulator pressure _ ___f_ Shift Control Solenoid Valves
F_ Lock_up Control Solenoid ValvesL_ Linear Solenoid
. 1-2 Shift Valve - l. 2-3 Shift Valve - 1- Ctutch pressure. 3-4 Shift Valve
lra
PORT NO.DESCRIPTION OF PRESSUREPORT NO.DESCRIPTION OF PRESSUREPORT NO.DESCRIPTION OF PRESSURE
1LINE6B
MODULATE(SHIFT CONTROL
SOLENOID VALVE B)
414TH CLUTCH
LINEMODULATE(LOCK-UP CONTROL
SOLENOID VALVE A)
56LINEAR SOLENOID
LINE6D
MODULATE(LOCK-UP CONTROL
SOLENOID VALVE B)
90TOROUE CONVEBTER
2LINE6D'
MODULATE
(LOCK-UP CONTROL
SOLENOID VALVE B)
91TOROUE CONVERTER
LINE7LINE92TOROUE CONVERTERLINE8LINE/CPC93ATF COOLER3"LINE9LINE94TOROUE CONVERTER4LIN E'101ST CLUTCH95LUBRICATION
LINE202ND CLUTCHYOTOROUE CONVERTERLINE20A2ND ACCUMULATOR97TOROUE CONVERTER5LINE99SUCTION
MODULATE303RD CLUTCHXDRAIN
6A
MODULATE(SHIFT CONTROL
SOLENOID VALVE A)
404TH CLUTCH
14-24
Page 704 of 2189

Description
Hydraulic Flow (cont'd)
L?j Position
The line pressure (1) flows to the manual valve and the modulator valve. The line pressure (1) changes the trne pressure(4) and (25) at the manual valve. and changes to the modulator pressure at the modulator valve. But the moourator pres-sure (6) does not flow to each shift valve because shift control solenoid valves A and B are turned oN by the pcM. Theline pressure (4) passes through the cPB valve and the cPc valve. and changes to the line pressure (s), th;n flows to the1-2 shift valve. The line pressure {S) from the l-2 shift valve changes to the 2nd clutch pressure (20) at the 2-3 shift valve.The 2nd clutch pressure (20) is applied to the 2nd clutch. and the 2nd clutch is engaged. The line pressure (4) passesthrough the 1-2 shift valve and the orifice, and changes the lst clutch pressure, The 1st clutch pressure (10) atso flows tothe 1st clutch. However, no power is transmitted because of the one_way clutch.
NOTE: When used, "Ieft" or "right" indicates direction on the hvdraulic circuit.
14-26
Page 709 of 2189

L
E Position
The flow of fluid through the torque convefter circuit is the same as in E position The line pressure (1) changes to the
line pressure (3) and flows to the l-2 shift valve. The iine pressure (3) changes to the line pressure (3') at the 'l-2 shift valve
and flows to the servo valve. The servo valve is moved to the right side (Reverse range position) and uncovers the port to
allow line pressure {3") to the manual valve, The line pressure {3') from the 1-2 shift valve flows through the servo valve to
the manual valve and changes the 4th clutch pressure (40). The 4th clutch pressure (40) is applied to the 4th clutch, and
the 4th clutch is engaged,
Reverse Inhibitor Control
When the E position is selected while the vehicle is moving forward at spe€ds over 6 mph (10 km/h)' the PCM outputs the
1st speed signal to shift control solenoid valves A and B; shift control solenoid valve A is turned oFF, shift control solenoid
valve B is turned ON. The 1-2 shift valve is moved to the right side and covers the port to stop line pressure (3') to the
servo valve. The line pressure (3' ) is not applied to the servo valve, and the 4th clutch pressure (40) is not applied to the
4th clutch, as a result, power is not transmitted to the reverse direction'
When used. 'left" or "right" indicates direction on the hydraulic circuit'
14-31
Page 712 of 2189

Description
Lock-up System (cont'd)
TOROUE CONVERTER
In B.rl position, in 3rd and 4th, and lDl_- position in 3rd.pressurized fluid is drajned from the back of the torqueconverter through a fluid passage. causing the lock-uppiston to be held against the torque convener cover. Asthis takes place, the mainshaft rotates at the same speedas the engine crankshaft, Together with the hydrauliccontrol, the PCM optimized the timing of the lock_upsystem. Under certain conditions, the lock_up clutch isapplied during deceleration, in 3rd and 4th gear.
The lock-up system controls the range of lock_up accord_ing to lock-up control solenoid valves A and B. and thelinear solenoid. When lock-up control solenoid valves Aand B activate, modulator pressure changes. Lock_upcontrol solenoid valves A and B and the linear solenoidare mounted on the outside of the torque converterhousing. and are controlled by the pclvl.
Lock-up Conditions/Lock-up Control Solenoid Valves/Linear Solenoid Pressure
MODULATOR PRESSURE
.-- LINEAR SOLENOID PRESSURE
LOCK.UP CONTROL. VALVE
LOCK.UP CONTROLSOLENOID VALVELock-up
Conditions
Lock-up Control
Solenoid ValveLineal
Solenoid
PressureAB
Lock-up OFFOFFOFFHig h
Lock-up. HalfONDuty operation
OFF - ON
Lock-up. FullONONHigh
Lock-up
during
decelerationONDuty operation
OFF * ONLowTOROUE CONVERTERCHECI( VALVE
RELIEF VAI-VE
LOCK.UP TIMINGVALVE
^ r______rr r cooLER RELTEF VALVE
t'-
14-34
ATF PUMP
Page 783 of 2189

Lock-up Gontrol Solenoid Valve A/B Assembly
Test
'1, Disconnect the 2P connector from the
trol solenoid valve 1y'8 assembly.
TERMINAL SIOE OF
MALE TERMINALS
tocK-up con-
LOCK.UP CONTROLSOLENOID VALVE A/BASSEMBLY
Measure the resistance between the No. 2 terminal
(solenoid valve A) of the lock-up control solenoid
valve connector and body ground, and between the
No. 1 terminal (solenoid valve Bl and body ground.
STANDARD: 12 - 25 O
Replace the lock-up control solenoid valve assem-
bly if the resistance is out of specification.
lf the resistance is within the standard, connect the
No. 1 terminal of the lock-up control solenoid valve
connector to the battery positive terminal. A clicking
sound should be heard. Connsct the No. 2 terminal to
the battery positive terminal. A clicking sound should
be heard. Replace the lock-up control solenoid valve
assembly if no clicking sound is heard.
Replacement
NOTE: Lock-up control solenoid valves A and I must bs
removed/replaced as an assembly.
1. Remove the mounting bolts and lock-up control
solenoid valve Ay'B assemblv.
6 r 1.0 mm12 N.m (1.2 kgf.m,8.7 lbl.ftl
/:'-
Clean the mounting surfaceand fluid psssages.
Clean the mounting surface and fluid passages of
th6 lock-up control solenoid valve assembly, and
instsll a new lock-up control sol€noid valve Ay'B with
a new filtsr/gask€t.
Check the connector for rust, dirt or oil, and racon-
nect it securely.
1+105
Page 784 of 2189

Shift Control Solenoid Valve A/B Assembly
Test
1. Disconnect the 2P connector from the shift control
solenoid valve A,/B assemblv.
SHIFT CONTROLSOLENOID VALVE A/B
ASSEMBLY
N4easure the resistance between the No. 1 terminal(solenoid valve A) of the shift control solenoid valve
connector and body ground, and between the No. 2
terminal (solenoid valve B) and body ground.
STANDARD: 12 - 25 O
Replace the shift control solenoid valve assembly if
the resistance is out of specification,
lf the resistance is within the standard, connect the
No. 1 te.minal of the shift control solenoid valve
connector to the battery positive terminal. A clicking
sound should be heard. Connect the No. 2 terminal
to the battery positive terminal. A clicking sound
should be heard. Replace the shift control solenoid
valve assembly if no clicking sound is heard.
14-106
Replacement
NOTE: Shift control solenoid valves A and B must be
removed/replaced as an assembly.
1. Remove the mounting bolts and shift control solenoid
valve A,/B assembly.
5xL0mm12 N.m(1.2 kgf.m,8.7 lbf.ft)CONNECTOR BRACKET
FILTER/GASKETBeplace.Clean the mounting surfaceand fluid passages.
Clean the mounting surface and fluid passages of
the shift control solenoid valve assembly, and
install a new shift control solenoid valve Ay'B with a
new filter/gasket and the clamp bracket.
Check the connector for rust. dirt or oil. and recon-
nect it securelv,