A/T CONTROL SYSTEM
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Control ValveBCS000ZW
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.
AT-36
TROUBLE DIAGNOSIS
How to Perform Trouble Diagnoses for Quick and Accurate RepairBCS000ZZ
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelera-
tor pedal position sensor or PNP switch and provides shift control or
lock-up control via A/T solenoid valves.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a malfunction that occurs inter-
mittently rather than continuously. Most intermittent malfunctions are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only, may not find the cause of the malfunctions. A
road test with CONSULT-II or a circuit tester connected should be
performed. Follow the AT- 3 7 , "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a drivability complaint. The customer
can supply good information about such malfunctions, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” like the
example (AT- 3 8 , "
DIAGNOSTIC WORKSHEET" ) should be used.
Start your diagnosis by looking for “conventional” malfunctions first.
This will help troubleshoot drivability malfunctions on an electroni-
cally controlled engine vehicle.
Also check related Service bulletins for information.
SAT631IA
SAT632I
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TROUBLE DIAGNOSIS
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CONSULT-II Function (A/T) BCS0010D
CONSULT-II can display each diagnostic item using the diagnostic test models shown following.
FUNCTION
NOTICE:
1. The CONSULT-II electrically displays shift timing and lock-up timing (that is, operation timing of each sole-
noid).
Check for time difference between actual shift timing and the CONSULT-II display. If the difference is
noticeable, mechanical parts (except solenoids, sensors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) displayed on CONSULT-II and that indicated in Service Man-
ual may differ slightly. This occurs because of the following reasons:
–Actual shift schedule has more or less tolerance or allowance,
–Shift schedule indicated in Service Manual refers to the point where shifts start, and
–Gear position displayed on CONSULT-II indicates the point where shifts are completed.
3. Shift solenoid valve “A” or “B” is displayed on CONSULT-II at the start of shifting. Gear position is dis-
played upon completion of shifting (which is computed by TCM).
CONSULT-II REFERENCE VALUE
Diagnostic test mode Function Reference page
Work supportThis mode enables a technician to adjust some devices faster and more accurately by
following the indications on CONSULT-II.—
Self-diagnostic results Self-diagnostic results can be read and erased quickly.AT- 6 9
Data monitor Input/Output data in the ECM can be read.AT- 7 0
CAN diagnostic support
monitorThe results of transmit/receive diagnosis of CAN communication can be read.AT- 7 2
Function testPerformed by CONSULT-II instead of a technician to determine whether each system
is “OK” or “NG”.—
DTC work support Select the operating condition to confirm Diagnosis Trouble Codes.AT- 7 2
TCM part number TCM part number can be read. —
Item name Condition Display value (Approx.)
VHCL/S SE-A/T
During drivingApproximately matches the speedometer
reading.
VHCL/S SE-MTR
THROTTLE POSIReleased accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8.0/8
FLUID TEMP SE When ATF temperature is 20°C (68°F). 1.5 V
When ATF temperature is 80°C (176°F). 0.5 V
BATTERY VOLT When turning ignition switch to ON. Battery voltage
ENGINE SPEED Engine runningApproximately matches the tachometer
reading.
TURBINE REV During driving (lock-up ON) Approximately matches the engine speed.
OVERDRIVE SWWhen setting selector lever to “3” and “2” posi-
tions.ON
When setting selector lever to other positions. OFF
PN POSI SWWhen setting selector lever to “N” or “P” posi-
tion.ON
When setting selector lever to other positions. OFF
R POSITION SWWhen setting selector lever to “R” position. ON
When setting selector lever to other positions. OFF
AT-76
TROUBLE DIAGNOSIS
Diagnostic Procedure Without CONSULT-IIBCS0010E
TCM SELF-DIAGNOSTIC PROCEDURE (WITHOUT CONSULT-II)
Description
If a malfunction occurs in electrical system, check the self-diagnostic result after confirming A/T CHECK indi-
cator lamp works. To detect a malfunction, entering a self-diagnosis start signal retrieves information on mal-
functions from memory and indicates malfunction by blinking A/T CHECK indicator lamp.
Diagnostic Procedure
1. CHECK A/T CHECK INDICATOR LAMP
1. Park vehicle on flat surface.
2. Move selector lever to “P” position.
Start engine and warm it up to normal engine operating temperature.
3. Turn ignition switch OFF.
4. Wait 5 seconds.
5. Turn ignition switch ON. (Do not start engine.)
Does A/T CHECK indicator lamp come on for about 2 seconds?
YES >> GO TO 2.
NO >> Stop procedure. Perform AT- 1 7 3 , "
A/T CHECK Indicator Lamp Does Not Come On" before pro-
ceeding.
2. JUDGEMENT PROCEDURE STEP 1
1. Turn ignition switch OFF.
2. Push and hold shift lock release button.
3. Depress the brake pedal, then move gear selector lever from “P” to “3” position.
4. Turn ignition switch ON. (Do not start engine.)
5. Wait 3seconds.
6. Move selector lever to “2” position.
7. Release brake pedal.
8. Move selector lever to “1” position.
9. Depress brake pedal.
10. Depress accelerator.
11. The A/T CHECK indicator lamp will begin to flash.
>> GO TO 3.
3. CHECK SELF-DIAGNOSTIC CODE
Check A/T CHECK indicator lamp. Refer to AT- 7 7 , "
Judgement of Self-Diagnosis Code" .
>>DIAGNOSIS END
TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-195
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Lock-up Is Not ReleasedBCS0014M
SYMPTOM:
Lock-up is not released when accelerator pedal is released on “Cruise Test — Part 1”.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to EC-82, "
SELF-DIAG RESULTS MODE" (QR engine) or EC-427, "SELF-
DIAG RESULTS MODE" (VQ engine).
Is any malfunction detected by self-diagnostic results?
YES >> Check the malfunctioning systems. Refer to EC-82, "SELF-DIAG RESULTS MODE" (QR engine)
or EC-427, "
SELF-DIAG RESULTS MODE" (VQ engine).
NO >> GO TO 2.
2. SYMPTOM CHECK
Check again. Refer to AT- 5 0 , "
Cruise Test — Part 1" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
3. CHECK TCM
1. Check TCM input/output signals. Refer to AT- 6 4 , "
TCM Terminals and Reference Value" .
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Engine Speed Does Not Return To Idle (Light Braking D4 → D3 )BCS0014N
SYMPTOM:
Engine speed does not smoothly return to idle when A/T shifts from D4 to D3 on “Cruise Test — Part
1”.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 6 9 , "
SELF-DIAGNOSTIC RESULT MODE" or AT- 7 6 , "Diagnostic Proce-
dure Without CONSULT-II" .
Is any malfunction detected by self-diagnostic results?
YES >> Check the malfunctioning systems. Refer to AT- 6 9 , "SELF-DIAGNOSTIC RESULT MODE" or AT-
77, "Judgement of Self-Diagnosis Code" .
NO >> GO TO 2.
2. CHECK ACCELERATOR PEDAL POSITION SENSOR
Check accelerator pedal position sensor. Refer to EC-272, "
DTC P2138 APP SENSOR" (QR engine) or EC-
652, "DTC P2138 APP SENSOR" (VQ engine).
OK or NG
OK >> GO TO 3.
NG >> Repair or replace accelerator pedal position sensor.
SHIFT CONTROL SYSTEM
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SHIFT CONTROL SYSTEMPFP:34901
Control Device Removal and InstallationBCS0014W
CONTROL DEVICE COMPONENTS
CONTROL CABLE COMPONENTS
1. Selector lever knob 2. Lock pin 3. A/T console finisher
4. Control device assembly 5. Knob cover
SCIA7870E
1. Control device assembly 2. Lock plate 3. Bracket
4. Control cable 5. Bracket 6. Transaxle
7. Lock plate 8. Bracket 9. Floor panel
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AT-214
SHIFT CONTROL SYSTEM
REMOVAL
1. Remove knob cover below selector lever downward.
2. Pull lock pin out of selector lever knob.
3. Remove selector lever knob.
4. Remove A/T console finisher. Refer to IP-11, "
Removal and Installation" .
5. Remove center console assembly. Refer to IP-11, "
Removal and Installation" .
6. Remove lock plate from control cable.
7. Disconnect control cable of control device assembly.
8. Disconnect control device harness connector.
9. Remove control device assembly from vehicle.
INSTALLATION
Note the following, and install in the reverse order of removal.
After installation is completed, adjust and check A/T position. Refer to AT- 2 1 5 , "Adjustment of A/T Posi-
tion" and AT- 2 1 5 , "Checking of A/T Position" .
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SHIFT CONTROL SYSTEM
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Adjustment of A/T PositionBCS0014X
Move selector lever from “P” position to “1” position. You should be
able to feel the detents in each position. If the detents cannot be felt
or if the pointer indicating the position is improperly aligned, the con-
trol cable needs adjustment.
1. Place selector lever in “P” position.
2. Loosen control cable lock nut and place manual shaft in “P”
position.
CAUTION:
Turn wheels more than 1/4 rotations and apply the park
lock.
3. After pushing the control cable with the specified force, move
your hands off the control cable.
4. Connect control cable on manual shaft.
CAUTION:
No application of a force to the manual lever.
5. Tighten control cable lock nut.
6. Move selector lever from “P” to “1” position again. Make sure that selector lever moves smoothly.
7. Apply grease to contacting areas of selector lever and control cable. Install any part removed.
Checking of A/T PositionBCS0014Y
1. Place selector lever in “P” position, and turn ignition switch ON. (Do not start engine.)
2. Make sure selector lever can be shifted to other than “P” position when brake pedal is depressed. Also
make sure selector lever can be shifted from “P” position only when brake pedal is depressed.
3. Move selector lever and check for excessive effort, sticking, noise or rattle.
4. Confirm selector lever stops at each position with the feel of engagement when it is moved through all the
positions. Check whether or not the actual position selector lever is in matches the position shown by the
shift position indicator and transaxle body.
5. The method of operating selector lever to individual positions
correctly should be as shown in the figure.
6. Confirm back-up lamps illuminate only when lever is placed in
“R” position. Confirm back-up lamps do not illuminate when
selector lever is in “P” or “N” position with selector lever pushed
against “R” position.
7. Confirm engine can only be started with selector lever in “P” and
“N” positions.
8. Make sure transaxle is locked completely in “P” position.Specified force: 9.8 N (1.0 kg, 2.2 lb)
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