Page 555 of 1395

Lock-up System
TOROUE CONVERTER
In E position ('97 - 98 models) and in E position ('99 -
OO models) (3rd and 4th), and E position ('97 - 98 mod-
els) and in E position with Over-Drive (O/D) is OFF (by
pressing the O/D switch) ('99 - 00 models) (3rd), pressur-
ized fluid is drained from the back of the torque convert-
er through a fluid passage, causing the lock-up piston to
be held against the torque converter cover, As this takes
Dlace, the mainshaft rotates at the same speed as th8
engine crankshaft. Together with the hydraulic control,
the PCM optimizes the timing of the lock-up system.
Under certain condltions. the lock-up clutch is appli€d
during deceleration, in 3rd and 4th gear.
The lock-up system controls the range of lock-up sccord-
ing to lock-up control solenoid valves A and B, and ths
linear solenoid. 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 out-
side of the torque converter housing, and the linear
solenoid is mounted on the transmission housing. They
are controlled bv the PCM.
The table below shows the lock-up conditions for lock-up
control solenoid valves and linear solenoid pressure.
LINEAR SOLENOID PRESSURE
(cont'd)
LOCK.UP CONTROL' VALVE
LOCK.UP CONTROLSOLENOID VALVE
AB
MODULATORPf,ESSURE
MAINSHAFT
COUNTERSHAFT
SUB.SHAFT
Lock-up
Conditions
Lock-up Conirol
Solenoid valveLinaal
Solenoid
PrgssulsAB
Lock-up OFFOFFOFFHigh
Lock-up, HalfONDuty operation
OFF - ONLow
Lock-up, FullONONHigh
Lock-up
during
deceleration
ONDuty operation
OFF - ON
RELIEF VALVE
LOCK'UP TIMINGVALVE
COOLER RELIEF VALVE
ATF COOLERATF STRAINER
ATF PUMP
14-39
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Page 557 of 1395
TOROUE CONVERTER
No Lock-up
. Lock-up Control Solenoid Valve A: OFF
. Lock-up Control Solenoid Valve B: OFF
. Linear Solenoid Pressure: High
The pressurized fluid regulated by the modulator works
on both ends of the lock-up shift valve. Under this condi-
tion, the pressures working on both ends of the lock-up
shift valve are equal. and the lock-up shift valve is
moved to the right side by the tension of the valve
spring. Fluid trom the ATF pump will flow through the
left side of the lock-up clutch to the torque converter; the
lock-up clutch is OFF.
NOTE: When us€d, "|eft" and "right" indicates direction
on the hydraulic circuit.
+ LINEAR SOLENOID PRESSURE
(cont'd)
LOCK.UP CONTROLSOI-ENOID VALVE
MOOULATORPRESSURE
MAINSHAFT
COUNTERSHAFTRELIEF VALVE
LOCK-UP TIMINGVALVE
i COOLER RELIEF VALVE
ATF STRAINERATF COOLER
ATF PUMP
14-41
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Page 558 of 1395

Description
Lock-up System (cont'dl
a
a
Half Lock-up
Lock-up Control Solenoid Valve A: ON
Lock-up Control Solenoid Valve B: Duty Operation
OFF - ON
Linear Solenoid Pressure: Low
The PCM switches solenoid valve A on to release modu-
lator pressure 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, and the lock-up
shift valve is moved to the left side.
Line pressure is then separated into the two passages to
the torque converter; torque converter inner pressure
enters into right side to engage the lock-up clutch, and
torque convener back Dressure enters into left side to
disengage the lock-up clutch.
Back pressure (F2) is regulated by the lock-up control
valve, whereas the position of the lock-up timing valve
is determined by linear solenoid pressure and tension of
the valve spring. Also the position of the lock-up control
valve is determined by the back pressure of the lock-up
control valve. torque converter pressure (regulated by
the torque converter check valve), and modulator pres-
sure (determined by the lock-up control solenoid valve
B). The PCM switches lock-up control solenoid valve B
on and off rapidly (duty operation), under certajn condi-
tions, to regulate back pressur€ (F2) and lock the torque
convertef.
NOTE: When used, "left" and "right" indicates direction
on the hvdraulic circuit.
+ LINEAR SOLENOID PRESSURE
TOFOUE CONVERTER
L(rcK.UP CONTROLSOLENOID VALVE
AB
MODULATORPNESSURE
MAINSHAFT
COUNIERSHAFTRELIEF VALVE
L(rcK-UP TIMINGVALVE
COOLER RELIEF VALVE
ATF STRAINER
14-42
ATF COOLER
ATF PUMP
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Page 559 of 1395

TOROUE CONVEFTER
Full Lock-up
. Lock-up Control Solenoid Valve A: ON
. Lock-up Control Solenoid Valve B: ON
. Linear Solenoid Pressure: High
When the vehicle speed further increases, linear
solenoid pressure increases to high in accordance with
the linear solenoid which is controlled by the PCM.
The lock up timing valve overcomes the spring force
and moves to the left side. Also, this valve closes the
fluid port leading to the left side of the lock-up control
valve.
Under this condition, modulator pressure in the left side
of the lock-up control valve had already been released
by the lock-up control solenoid valve B; the lock-up con-
trol valve is moved to the left side. As this takes place,
torque converter back pressure is released fully, causing
the lock-up clutch to be engaged fully.
NOTE: When used. "left" and "right" indicates direction
on the hydraulic circuit.
+ LINEAR SOLENOIO PRESSURE
(cont'd)
LOCK-UP CONTROLSOLENOID VALVE
MODULATORPRESSURE
MAINSHAFT
COUNTERSHAFT
SUB-SHAFT
RELIEF VALVE
LOCK.UP TIMINGVALVE
COOLER BELIEF VALVE
ATF STRAINERATF COOLER
ATF PUMP
14-43
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Page 560 of 1395
Description
Lock-up System (cont'dl
a
a
Decelelation Lock-up
Lock-up Control Solenoid Valve A: ON
Lock-up Control Solenoid Valve B; Duty Operation
OFF - ON
Linear Solenoid Pressure: Low
The PCM switches solenoid valve B on and off rapidly
under certain conditions. The slight lock-up and half
lock-up regions are maintained to lock the torque con-
vener propeny.
NOTE: When used, "left" and "right" indicates direction
on the hydraulic circuit.
+ LINEAR SOLENOID PRESSURE
TOROUE CONVERTER
tMOOULATORPRESSURE
MAINSHAFT
COUNTERSHAFT
SUB.SHAFT
ATF COOLER
RELIEF VALVE
LOCK.UP TIMINGVALVE
COOLER RELIEF VALVE
14-44
ATF STBAINER
ATF PUMP
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Page 599 of 1395

From page 14 82
Replace the Lock-up ControlSolenoid Valve Assembly andRecheck:1. Replace the lock-up controlsolenoid valve A/B assembly(see page 14-'135).2. Turn the ignition switch OFFand reset the PCM by remov-ing the BACK uP (7.5 A) fusein the under-hood fuse/relaybox for more than 10 seconds.3. lJsing the scan tool, check tobe sure that the engine coolanttemperature is 176"F 180'C) orabove,4. Drive the vehicle at 55 mph(88 km/h) constantly for moretnan one mrnute.5. Recheck for code P0740 (40).
Does the OBD ll scan tool indicatecode PO74O or doesthe El indicator light indicate code 40?The svstem is OK ai this time.
Replace the Linear Sol€noidA$embly and Recheck:'1. Beplace the linear solenoidassembly {see page 14-138).2. Turn the ignition switch OFFand reset the PCM memory byremoving the BACK UP (7.5 A)fuse in the underhood fuse/relay box for more than 10seconds.3. Using the scan tool, check tobe sure that the engine coolanttemperature is 176"F (80'C) orabove.4. Drive the vehicle at 55 mph (88
km/h) constantly for more thanone minute,5. Recheck for code P0740 {40).
Does the OBD ll scan toolindicate code P0740 or doesthe E indicator light indicate code 40?
The svsteo is OK at this tim€.
Replace the transmission andtorque convertor assembly.
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Page 670 of 1395

Symptom-to-Component Chart
Hydraulic System (cont'd)
SYMPTOMCheck these items on thePROBABLE CAUSE ListCheck these items onthe NOTES Lisr
Shift lever does not operate smoothly.o, JdPFails to shift; stuck in 4th gear.14, 41 , 48
Transmission will not shift into park in E position.6, 38, 61PStall rpm high; all clutch pressures are in specification.40D,K,OLock-up clutch does not disengage.18, 43, 44, 45, 46, 49,50,57
Lock-up clutch does not operate smoothly.14, 40, 43, 44, 45, 46, 49, 50. 57Lock-up clutch does not engage.'t8, 40, 43, 44, 45, 46, 49, 50, 56, 57Vibration in all positions.
No engine braking in I position.59
Shift position indicator does not indicate anv position,6. 38, 60
PROBABLE CAUSE
I 33 Thrust washer worn/damaged
ATF pump worn or binding34Clutch clearance incorrect
Regulator valve stuck or regulator valvespflng wornDrive plate delective or transmission mtsas-sembled
Servo valve stuck5ttTorque converter housing or transmissionhousing bearing worn/damagedMainshaft worn/damaged
Shift cable broken/out of adjustmentATF strainer clogged
7Final gears worn/damaged38Shift cable is worn where it attaches to thetransmission or at the body mountsIOne-way (sprag) clutch worn/damaged
1st gears worn/damaged {2 gears)39Modulator valve stuck10lst clutch defective40Torque converter check valve stuck112nd gears worn/damaged (2 gears)41Foreign material in separator plate't22nd clutch defectiveCPB valve stuck
t53rd clutch defective43Lock-up timing valve stuck144th clutch defective44Lock-up shift valve stucktcReverse gears worn/damaged (3 gears)Lock-up control valve stuck16Excessive ATF46Lock-up clutch Diston defective17Torque converter one-way clutch defective47Shift control solenoid valve A defecttve
18Linear solenoid assemblv defective (,98 - OOmodels)48Shift control solenoid valve B dsfectrve
49Lock-up control solenoid valve A defective'19CPC valve stuckLock-up control solenoid valve B deleqtve20l-2 shift valve stuck51Servo control valve stuck212-3 shift valve stuck52lst accumulator defective3-4 shift valve stuck53Foreign material in 2nd exhaust orifice2nd accumulator defective54Foreign material in 3rd exhaust orifice3rd accumulator defectiveForeign material in 4th exhaust orifice4th accumulator defective56Mainshaft speed sensor defective262nd orifice control valve stuckCountershaft speed sensor defective273-4 orifice control valve stuck583rd sub accumulator defective2aForeign material in main orifice59lst-hold clutch defective29Foreign material in lst orifice60A/T gear position switch defective or out ofadjustment30Foreign material in reverse orifice
31Engine output low61Park gear mechanism defective32Needle bearing worn/damaged
14-154
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Page 671 of 1395

The following symptom can be caused
by improper repair or assemblYCheck these items
. lmproper clutch clearance
. lmproper gear clearance
One-way (sprag) clutch installed upside down
Park lever installed upside down
Shift fork bolt not installed
Vehicle creeps in N position.
Vehicle does not move in E, [D.lj, or E
position.
Transmission locks up in E position.
Excessive drag in transmission.ATF pump binding and seizure
Use proper tools when replacing the ATF pump gears, and be careful
to damage the ATF pump when torque down the main valve body.
Check that the shift fork bolt is installed on the shift fork shaft
not
Excessive vibration, rpm related.Torque converter not fully seated in ATF pump
Reverse selector hub installed upside downNoise only with wheels moving.
Mainshaft oil seal po9s out.Mainshaft oil seal improperly installed
lnstallthe mainshaft oil seal tlush with the torque converter housing lf
the mainshaft oil seal is installed into the torque converter housing until
it bottoms. it will block the fluid return passage and result in damage
Various shifting problems.. Springs improperly installed
. Valves improperly installed
Harsh upshift.Check valve balls not installed
(cont'd)
4-155
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