OVERALL SYSTEM
AT-37
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TORQUE CONVERTER CLUTCH SOLENOID VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released
In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid applying pressure is drained and the torque converter clutch piston
release pressure is generated.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid applying pressure is generated and the torque converter clutch piston
release pressure is drained.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-Clutched State
The current output from the TCM to the torque converter clutch solenoid is varied to steadily increase the
torque converter clutch solenoid pressure.
In this way, the lock-up applying pressure gradually rises and while the torque converter clutch piston is
put into half-clutched status, the torque converter clutch piston operating pressure is increased and the
coupling is completed smoothly.
Engine Brake Control (Overrun Clutch Control)ECS00CTF
Forward one-way clutch is used to reduce shifting shocks in downshifting operations. This clutch transmits
engine torque to the wheels. However, drive force from the wheels is not transmitted to the engine because
the one-way clutch rotates idle. This means the engine brake is not effective.
The overrun clutch operates when the engine brake is needed.
SCIA5623E
OVERALL SYSTEM
AT-39
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Control ValveECS004QG
FUNCTION OF CONTROL VALVES
Valve name Function
Pressure regulator valve, plug and sleeve
plugRegulates oil discharged from the oil pump to provide optimum line pressure for all driv-
ing conditions.
Pressure modifier valve and sleeve Used as a signal supplementary valve to the pressure regulator valve. Regulates pres-
sure-modifier pressure (signal pressure) which controls optimum line pressure for all
driving conditions.
Pilot valve Regulates line pressure to maintain a constant pilot pressure level which controls lock-up
mechanism, overrun clutch, shift timing.
Accumulator control valve Regulates accumulator back-pressure to pressure suited to driving conditions.
Manual valve Directs line pressure to oil circuits corresponding to select positions.
Hydraulic pressure drains when the shift lever is in Neutral.
Shift valve A Simultaneously switches three oil circuits using output pressure of shift solenoid valve A
to meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and upshifting (1st → 2nd → 3rd → 4th gears/4th →
3rd → 2nd → 1st gears) in combination with shift valve B.
Shift valve B Simultaneously switches two oil circuits using output pressure of shift solenoid valve B in
relation to driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and upshifting (1st → 2nd → 3rd → 4th gears/4th →
3rd → 2nd → 1st gears) in combination with shift valve A.
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simultaneously
with application of the brake band in D
4 . (Interlocking occurs if the overrun clutch
engages during D
4 .)
1st reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when downshift-
ing from the 1st position 1
2 to 11 .
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In the 1st and 2nd positions, line pressure acts on the overrun clutch reducing valve to
increase the pressure-regulating point, with resultant engine brake capability.
Torque converter relief valve Prevents an excessive rise in torque converter pressure.
Torque converter clutch control valve, plug
and sleeveActivates or inactivates the lock-up function.
Also provides smooth lock-up through transient application and release of the lock-up
system.
1-2 accumulator valve and piston Lessens the shock find when the 2nd gear band servo contracts, and provides smooth
shifting.
3-2 timing valve Switches the pace that oil pressure is released depending on vehicle speed; maximizes
the high clutch release timing, and allows for soft downshifting.
Shuttle valve Determines if the overrun clutch solenoid valve should control the 3-2 timing valve or the
overrun clutch control valve and switches between the two.
Cooler check valve At low speeds and with a small load when a little heat is generated, saves the volume of
cooler flow, and stores the oil pressure for lock-up.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
AT-47
[EURO-OBD]
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DTC WORK SUPPORT MODE WITH CONSULT-II
For details, refer to the separate “CONSULT-II Operations Manual”.
CONSULT-II Setting Procedure
1. Turn ignition switch “OFF”.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector, which is located in instrument lower panel on
driver side.
GEAR — XGear position recognized by the TCM
updated after gear-shifting
SLCT LVR POSI — XSelector lever position is recognized by
the TCM.
For fail-safe operation, the specific value
used for control is displayed.
VEHICLE SPEED (km/h) — X Vehicle speed recognized by the TCM.
THROTTLE POSI (0.0/8) — XDegree of opening for accelerator recog-
nized by the TCM
For fail-safe operation, the specific value
used for control is displayed.
LINE PRES DTY (%) — X
TCC S/V DUTY (%) — X
SHIFT S/V A (ON/OFF) — X
SHIFT S/V B (ON/OFF) — X
OVERRUN/C S/V (ON/OFF) — X
SELF-D DP LMP (ON/OFF) — X
TC SLIP RATIO (0.000) — —
TC SLIP SPEED (rpm) — —Difference between engine speed and
torque converter input shaft speed
Voltage (V) — —Displays the value measured by the volt-
age probe.
Frequency (Hz) — —
The value measured by the pulse probe
is displayed. DUTY·HI (high) (%) — —
DUTY·LOW (low) (%) — —
PLS WIDTH·HI (ms) — —
PLS WIDTH·LOW (ms) — —Monitor item (Unit)SELECT MONITOR ITEM
Remarks
TCM INPUT
SIGNALSMAIN SIG-
NALSSELEC-
TION FROM
MENU
SCIA0691E
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
AT-55
[EURO-OBD]
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6th judgement flicker is longer than others.
Overrun clutch solenoid valve circuit is short-circuited or discon-
nected.
Go to DTC P1760 OVERRUN CLUTCH SOLENOID VALVE.
Refer to AT- 1 7 87th judgement flicker is longer than others.
Torque converter clutch solenoid valve circuit is short-circuited or
disconnected.
Go to DTC P0740 TORQUE CONVERTER CLUTCH SOLE-
NOID VALVE.
Refer to AT-148
8th judgement flicker is longer than others.
A/T fluid temperature sensor is disconnected or TCM power sup-
ply circuit is damaged.
Go to DTC BATT/FLUID TEMP SEN (A/T FLUID TEMP SEN-
SOR CIRCUIT AND TCM POWER SOURCE).
Refer to AT-1849th judgement flicker is longer than others.
Engine speed signal circuit is short-circuited or disconnected.
Go to DTC P0725 ENGINE SPEED SIGNAL.
Refer to AT- 11 9
O/D OFF indicator lamp
SCIA5596ESCIA5597E
SCIA5598ESCIA5599E
TROUBLE DIAGNOSIS — INTRODUCTION
AT-59
[EURO-OBD]
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Diagnostic Worksheet
1.❏ Read the Fail-safe and listen to customer complaints.AT- 5 8
2.❏ Check A/T fluidAT- 6 4
❏ Leakage (Follow specified procedure)
❏ Fluid condition
❏ Fluid level
3.❏ Perform Stall Test and Line Pressure Test.AT- 6 5
, AT- 6 8
❏ Stall test — Mark possible damaged components/others.
❏ Torque converter one-way clutch
❏ Reverse clutch
❏ Forward clutch
❏ Overrun clutch
❏ Forward one-way clutch❏ Low & reverse brake
❏ Low one-way clutch
❏ Engine
❏ Line pressure is low
❏ Clutches and brakes except high clutch and
brake band are OK
❏ Line Pressure test — Suspected parts:
4.❏ Perform all Road Test and mark required procedures.AT- 7 0
4-1. Check before engine is started.AT- 7 1
❏ O/D OFF Indicator Lamp Does Not Come On, AT-204 .
❏ SELF-DIAGNOSTIC PROCEDURE/DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PRO-
CEDURE. — Mark detected items.
❏ PNP switch, AT- 1 0 0
.
❏ A/T fluid temperature sensor, AT- 1 0 6
.
❏ Vehicle speed sensor·A/T (Revolution sensor), AT- 11 2
.
❏ Engine speed signal, AT- 11 9
.
❏ Torque converter clutch solenoid valve, AT-148
.
❏ Line pressure solenoid valve, AT-154
.
❏ Shift solenoid valve A, AT- 1 6 1
.
❏ Shift solenoid valve B, AT- 1 6 7
.
❏ Accelerator pedal position (App) sensor, AT- 1 7 3
.
❏ Overrun clutch solenoid valve, AT- 1 7 8
.
❏ PNP & overdrive control switches, and throttle position sensor, AT- 2 3 7
.
❏ Batt/fluid temp sen (A/T fluid temperature sensor and TCM power source), AT- 1 8 4
.
❏ Vehicle speed sensor·MTR, AT-192
.
❏ CAN communication line, AT- 9 7
.
❏ Control unit (RAM), control unit (ROM), AT-198
.
❏ Control unit (EEP ROM), AT-200
.
❏ Battery
❏ Others
4-2. Check at idleAT- 7 2
❏ Engine Cannot Be Started In “P” And “N” Position, AT-206 .
❏ In “P” Position, Vehicle Moves Forward Or Backward When Pushed, AT-207
.
❏ In “N” Position, Vehicle Moves, AT- 2 0 8
.
❏ Large Shock. “N” → “R” Position, AT-209
.
❏ Vehicle Does Not Creep Backward In “R” Position, AT-210
.
❏ Vehicle Does Not Creep Forward In “D”, “2” Or “1” Position, AT- 2 1 2
.
AT-60
[EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
4. 4-3. Cruise testAT- 7 4
AT- 7 8Part-1
❏ Vehicle Cannot Be Started From D
1 , AT-214 .
❏ A/T Does Not Shift: D
1 → D2 Or Does Not Kickdown: D4 → D2 , AT- 2 1 7 .
❏ A/T Does Not Shift: D
2 → D3 , AT-220 .
❏ A/T Does Not Shift: D
3 → D4 , AT-222 .
❏ A/T Does Not Perform Lock-up, AT- 2 2 4
.
❏ A/T Does Not Hold Lock-up Condition, AT- 2 2 5
.
❏ Lock-up Is Not Released, AT- 2 2 7
.
❏ Engine Speed Does Not Return To Idle (Light Braking D
4 → D3 ), AT- 2 2 8 .
Part-2AT- 8 1
❏ Vehicle Does Not Start From D1 , AT-230 .
❏ A/T Does Not Shift: D
1 → D2 Or Does Not Kickdown: D4 → D2 , AT- 2 1 7 .
❏ A/T Does Not Shift: D
2 → D3 , AT-220 .
❏ A/T Does Not Shift: D
3 → D4 , AT-222 .
Part-3AT- 8 2
❏ A/T Does Not Shift: D4 → D3 When Overdrive Control Switch “ON” → “OFF”, AT- 2 3 1 .
❏ Engine Speed Does Not Return To Idle (Engine Brake In D
3 ), AT-228 .
❏ A/T Does Not Shift: D
3 → 22 , When Selector Lever “D” → “2” Position, AT-232 .
❏ Engine Speed Does Not Return To Idle (Engine Brake In 2
2 ), AT- 2 2 8 .
❏ A/T Does Not Shift: 2
2 → 11 , When Selector Lever “2” → “1” Position, AT- 2 3 3 .
❏ Vehicle Does Not Decelerate By Engine Brake, AT-235
.
❏ TCM Self-diagnosis Does Not Activate (PNP & Overdrive control switches, and throttle position sensor
circuit checks), AT-237
.
❏ SELF-DIAGNOSTIC PROCEDURE/DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PRO-
CEDURE — Mark detected items.
❏ PNP switch, AT-100
.
❏ A/T fluid temperature sensor, AT-106
.
❏ Vehicle speed sensor·A/T (Revolution sensor), AT- 11 2
.
❏ Engine speed signal, AT- 11 9
.
❏ Torque converter clutch solenoid valve, AT- 1 4 8
.
❏ Line pressure solenoid valve, AT-154
.
❏ Shift solenoid valve A, AT-161
.
❏ Shift solenoid valve B, AT-167
.
❏ Accelerator pedal position (App) sensor, AT-173
.
❏ Overrun clutch solenoid valve, AT-178
.
❏ PNP & overdrive control switches, and throttle position sensor, AT- 2 3 7
.
❏ A/T fluid temperature sensor and TCM power source, AT-184
.
❏ Vehicle speed sensor·MTR, AT- 1 9 2
.
❏ CAN communication line, AT- 9 7
.
❏ Control unit (RAM), control unit (ROM), AT- 1 9 8
.
❏ Control unit (EEP ROM), AT- 2 0 0
.
❏ Battery
❏ Others
5.❏ For self-diagnosis NG items, inspect each component. Repair or replace the damaged parts.AT- 5 2
6.❏ Perform all Road Test and re-mark required procedures.AT- 7 0
7.❏ Perform DTC Confirmation Procedure for following MI indicating items and check out NG items.EC-53
❏ DTC (P0731) A/T 1st gear function, AT-125 .
❏ DTC (P0732) A/T 2nd gear function, AT- 1 3 0
.
❏ DTC (P0733) A/T 3rd gear function, AT-135
.
❏ DTC (P0734) A/T 4th gear function, AT-140
.
8.❏ Perform the Diagnostic Procedures for all remaining items marked NG. Repair or replace the damaged parts.
Refer to the Symptom Chart when you perform the procedures. (The chart also shows some other possible
symptoms and the component inspection orders.)AT- 8 5
9.❏ Erase DTC from TCM and ECM memories.AT- 4 2
AT-66
[EURO-OBD]
TROUBLE DIAGNOSIS — BASIC INSPECTION
8. Move selector lever to N position.
9. Cool off ATF.
Run engine at idle for at least one minute.
10. Repeat steps 5 through 9 with selector lever in 2, 1 and R posi-
tions.
JUDGEMENT OF STALL TEST
The test result and possible damaged components relating to each result are shown in the illustrations on next
page.
In order to pinpoint the possible damaged components, follow the WORK FLOW shown in AT- 6 1 , "
Work Flow"
(EURO-OBD).
NOTE:
Stall revolution is too high in D, 2 or 1 position:
Slippage occurs in 1st gear but not in 2nd and 3rd gears...... Low one-way clutch slippage
Slippage occurs in the following gears:
1st through 3rd gears in D position and engine brake functions with overdrive control switch set to OFF.
1st and 2nd gears in 2 position and engine brake functions with accelerator pedal released (fully closed
throttle)...... Forward clutch or forward one-way clutch slippage
Stall revolution is too high in R position:
Engine brake does not function in 1 position...... Low & reverse brake slippage
Engine brake functions in 1 position...... Reverse clutch slippage
Stall revolution within specifications:
Vehicle does not achieve speed of more than 80 km/h (50 MPH)...... One-way clutch seizure in torque
converter housing
CAUTION:
Be careful since automatic fluid temperature increases abnormally.
Slippage occurs in 3rd and 4th gears in D position...... High clutch slippage
Slippage occurs in 2nd and 4th gear in D position...... Brake band slippage
Engine brake does not function in 2nd and 3rd gears in D position, 2nd gear in 2 position, and 1st gear in
1 position with overdrive control switch set to OFF...... Overrun clutch slippage
Stall revolution less than specifications:
Poor acceleration during starts...... One-way clutch slippage in torque converter
SAT771B
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-85
[EURO-OBD]
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TROUBLE DIAGNOSIS — GENERAL DESCRIPTIONPFP:00000
Symptom ChartECS004QU
Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Symptom Condition Diagnostic Item Reference Page
Engine cannot start in “P” and “N”
positions.
AT- 2 0 6
ON vehicle1. Ignition switch and starterPG-2
, SC-23
2. Control cable adjustmentAT-409
3. PNP switchAT-100
Engine starts in position other than
“N” and “P” positions.
AT- 2 0 6
ON vehicle1. Control cable adjustmentAT-4092. PNP switchAT-100
Transaxle noise in “P” and “N” posi-
tions.ON vehicle1. Fluid levelAT- 6 4
2. Line pressure testAT- 6 8
3. Accelerator pedal position (APP) sensorAT-173
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2,
AT-192
OFF vehicle5. Oil pumpAT-4436. Torque converterAT-423
Vehicle moves when changing into
“P” position, or parking gear does
not disengage when shifted out of
“P” position.
AT- 2 0 7ON vehicle 1. Control cable adjustmentAT-409
OFF vehicle 2. Parking componentsAT- 4 1 6, AT-440
Vehicle runs in “N” position.
AT- 2 0 8
ON vehicle 1. Control cable adjustmentAT-409
OFF vehicle2. Forward clutchAT-4753. Reverse clutchAT-464
4. Overrun clutchAT-475
Vehicle will not run in “R” position
(but runs in “D”, “2” and “1” posi-
tions). Clutch slips.
Very poor acceleration.
AT- 2 1 0
ON vehicle1. Control cable adjustmentAT-409
2. Stall testAT- 6 5
3. Line pressure testAT- 6 8
4. Line pressure solenoid valveAT-154
5. Control valve assemblyAT-404
Vehicle will not run in “R” position
(but runs in “D”, “2” and “1” posi-
tions). Clutch slips.
Very poor acceleration.
AT- 2 1 0
OFF vehicle6. Reverse clutchAT-464
7. High clutchAT-469
8. Forward clutchAT-475
9. Overrun clutchAT-475
10. Low & reverse brakeAT-483
Vehicle braked when shifting into
“R” position.ON vehicle1. Fluid levelAT- 6 4
2. Line pressure testAT- 6 8
3. Line pressure solenoid valveAT-154
4. Control valve assemblyAT-404
OFF vehicle5. High clutchAT-4696. Brake bandAT-497
7. Forward clutchAT-475
8. Overrun clutchAT-475