TM-344
< FUNCTION DIAGNOSIS >[TYPE 2 (4AT: RE4F03B)]
A/T CONTROL SYSTEM
Control Valve
INFOID:0000000001714318
FUNCTION OF CONTROL VALVES
Centrifugal Cancel MechanismINFOID:0000000001714319
FUNCTION
The centrifugal cancel mechanism is a mechanism to cancel the centrifugal hydraulic pressure instead of the
conventional check balls. It cancels the centrifugal hydraulic pressure which is generated as high clutch drum
rotates, and it allows for preventing high clutch from dragging and for providing stable high clutch piston press-
ing force in all revolution speeds.
STRUCTURE/OPERATION
Valve name Function
Pressure regulator valve, plug and sleeve
plugRegulates oil discharged from the oil pump to provide optimum line pressure for all driving
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 driv-
ing 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.
A/T CONTROL SYSTEM
TM-345
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A centrifugal cancel housing is provided to cancel the clutch housing pressure. The centrifugal cancel housing
is always filled with ATF from the dedicated fluid passage of oil pump.
When Clutch Pressure Is Not Applied
As high clutch drum rotates, a centrifugal force applies to the remaining ATF in clutch housing to push high
clutch piston. However, on the other hand, the centrifugal force also applies to ATF filled in centrifugal cancel
housing, resulting in a force that pushes high clutch piston back. Consequently the high clutch piston does not
move because both forces cancel each other, and thus high clutch is prevented from dragging.
When Clutch Pressure Is Applied
Clutch pressure that applies to clutch housing overcomes the fluid pressure and spring force of the opposing
centrifugal housing to push high clutch piston, and high clutch is engaged. At this time, the centrifugal force
caused by the revolution speed of high clutch drum has no impact any more since the centrifugal force that
applies to the clutch pressure of clutch housing is canceled by the centrifugal force that applies to centrifugal
cancel housing. As a result, high clutch piston pressing force is always stable in all revolution speeds, and
thus smooth shifting characteristics are achieved.
SCIA6832E
SCIA6833E
BATT/FLUID TEMP SEN (A/T FLUID TEMP SENSOR CIRCUIT AND TCM POW-
ER SOURCE)
TM-379
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7.CHECK A/T FLUID TEMPERATURE SENSOR WITH TERMINAL CORD ASSEMBLY
1. Turn ignition switch OFF.
2. Disconnect terminal cord assembly connector in engine room.
3. Check resistance between terminal cord assembly harness con-
nector terminals.
4. Reinstall any part removed.
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
8.DETECT MALFUNCTIONING ITEM
1. Remove oil pan. Refer to XX-XX, "*****"
.
2. Check the following items:
- A/T fluid temperature sensor
Check resistance between terminal cord assembly harness con-
nector terminals while changing temperature as shown.
- Harness of terminal cord assembly for short or open
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
9.CHECK DTC
Perform TM-376, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 10.
10.CHECK TCM
1. Check TCM input/output signal. Refer to XX-XX, "*****"
.
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.
Component InspectionINFOID:0000000001713041
A/T FLUID TEMPERATURE SENSOR
Temperature °C (°F) Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
SCIA4948E
Temperature [°C (°F)] Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
SAT298F
LINE PRESSURE SOLENOID VALVE
TM-387
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LINE PRESSURE SOLENOID VALVE
DescriptionINFOID:0000000001713056
The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in
response to signals sent from the TCM.
The line pressure duty cycle value is not constant when the closed throttle position switch is ON. To
confirm the line pressure duty cycle at low-pressure, the accelerator (throttle) should be open until the
closed throttle position switch is OFF.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001713057
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001713058
Diagnostic trouble code “LINE PRESSURE S/V” with CONSULT-III or 11th judgement flicker without CON-
SULT-III is detected when TCM detects an improper voltage drop while it tries to operate the solenoid valve.
Possible CauseINFOID:0000000001713059
Harness or connector
(Solenoid circuit is open or shorted.)
Line pressure solenoid valve
DTC Confirmation ProcedureINFOID:0000000001713060
CAUTION:
Always drive vehicle at a safe speed.
If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait at
least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Touch “START”.
3. Depress accelerator pedal completely and wait at least 1 second.
4. If the check result is NG, go to TM-387, "
Diagnosis Procedure".
WITHOUT CONSULT-III
1. Start engine.
2. With brake pedal depressed, shift the lever from “P”→“N”→“D”→“N”→“P” positions.
3. Perform self-diagnosis. Refer to TM-350, "
Diagnosis Procedure without CONSULT-III".
4. If the check result is NG, go to TM-387, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001713062
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Read out the value of “LINE PRES DTY” while driving. Check the value changes according to driving
speed.
Item name Condition Display value (Approx.)
LINE PRES DTYSmall throttle opening (Low line pressure) ⇔ Large
throttle opening (High line pressure)0% ⇔ 94%
A/T 4TH GEAR FUNCTION
TM-403
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A/T 4TH GEAR FUNCTION
DescriptionINFOID:0000000001713091
This malfunction will not be detected while the OD OFF indicator lamp is indicating another self-diagnosis
malfunction.
This malfunction is detected when the A/T does not shift into fourth gear position or the torque converter
clutch does not lock up as instructed by the TCM. This is not caused by electrical malfunction (circuits open
or shorted) but by mechanical malfunction such as control valve sticking, improper solenoid valve operation,
malfunctioning oil pump or torque converter clutch, etc.
CONSULT-III REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001713092
Diagnostic trouble code “A/T 4TH GR FNCTN” with CONSULT-III is detected when A/T cannot be shifted to
the 4th gear position even if electrical circuit is good.
This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by TCM
as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th) supposed by TCM, the slip ratio will be much
less than normal. In case the ratio does not reach the specified value, TCM judges this diagnosis malfunc-
tion.
This malfunction will be caused when shift solenoid valve B is stuck closed.
Gear positions supposed by TCM are as follows.
In case of gear position with no malfunctions: 1, 2, 3 and 4 positions
In case of gear position with shift solenoid valve A stuck open: 2, 2, 3 and 3* positions
In case of gear position with shift solenoid valve B stuck closed: 1, 2, 2 and 1* positions to each gear position
above
*: “A/T 4TH GR FNCTN” is detected.
Possible CauseINFOID:0000000001713093
Shift solenoid valve A
Shift solenoid valve B
Line pressure solenoid valve
Each clutch
Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001713094
CAUTION:
Always drive vehicle at a safe speed.
If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait at
least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Touch “START”.
Gear position 1 2 3 4
Shift solenoid valve A ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Shift solenoid valve B ON (Closed) ON (Closed) OFF (Open) OFF (Open)
Item name Condition Display value (Approx.)
LINE PRES DTYSmall throttle opening (Low line pressure) ⇔ Large
throttle opening (High line pressure)0% ⇔ 94%
TM-408
< COMPONENT DIAGNOSIS >[TYPE 2 (4AT: RE4F03B)]
A/T TCC S/V FUNCTION (LOCK-UP)
A/T TCC S/V FUNCTION (LOCK-UP)
DescriptionINFOID:0000000001713096
This malfunction will not be detected while the OD OFF indicator lamp is indicating another self-diagnosis
malfunction.
This malfunction is detected when the A/T does not shift into fourth gear position or the torque converter
clutch does not lock-up as instructed by the TCM. This is not caused by electrical malfunction (circuits open
or shorted) but by mechanical malfunction such as control valve sticking, improper solenoid valve operation,
malfunctioning oil pump or torque converter clutch, etc.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001713097
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001713098
Diagnostic trouble code “A/T TCC S/V FNCTN” with CONSULT-III is detected when A/T cannot perform
lock-up even if electrical circuit is good.
This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by TCM
as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th) supposed by TCM, the slip ratio will be much
less than normal. In case the ratio does not reach the specified value, TCM judges this diagnosis malfunc-
tion.
This malfunction will be caused when shift solenoid valve B is stuck closed.
Gear positions supposed by TCM are as follows.
In case of gear position with no malfunctions: 1, 2, 3 and 4 positions
In case of gear position with shift solenoid valve B stuck closed: 1, 2, 2 and 1* positions to each gear position
above
*: “A/T TCC S/V FNCTN” is detected.
Possible CauseINFOID:0000000001713099
Line pressure solenoid valve
Torque converter clutch solenoid valve
Each clutch
Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001713100
CAUTION:
Always drive vehicle at a safe speed.
If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait at
least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Touch “START”.
3. Make sure that output voltage of A/T fluid temperature sensor is within the range below.
FLUID TEMP SE: 0.4 - 1.5V
If out of range, drive vehicle to decrease voltage (warm up the fluid) or stop engine to increase voltage
(cool down the fluid).
4. Select “TCC S/V FNCTN P0744” of “DTC WORK SUPPORT” mode for “TRANSMISSION” with CON-
SULT-III and touch “START”.
Item name Condition Display value (Approx.)
TCC S/V DUTY Lock-up OFF ⇔ Lock-up ON 4% ⇔ 94%
TCM
TM-427
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The SELF-DIAGNOSIS results will be as follows:
The first SELF-DIAGNOSIS will indicate damage to the vehicle speed sensor or the revolution sensor.
During the next SELF-DIAGNOSIS, performed after checking the sensor, no damages will be indicated.
FAIL-SAFE FUNCTION
The following fail-safe functions allow vehicles to be driven even when sensor, switch or solenoid malfunction
occurs.
Vehicle Speed Sensor·A/T (Revolution Sensor)
Vehicle speed sensor·MTR signal is input from combination meter.
Accelerator Pedal Position Sensor Signal and Throttle Position Sensor Signal
TCM controls the throttle opening angle to a predetermined fixed position to enable driving if a malfunctioning
signal is input to TCM.
PNP Switch
When the multiple PNP switch signals are input to TCM, the priority of selector lever position becomes “D”,
“N”, “R”, “2” and “1” in order by internal TCM determination.
The use of 4th gear is inhibited until normal operation resumes. Because the hydraulic circuit of the control
valve is switched by manual valve according to the selector lever position, however, actual operating condition
of vehicle becomes as follows.
Shift Solenoid Valve A and B
If non-standard solenoid signal is sent to TCM, use of certain gears is limited. Refer to chart shown below.
●: Solenoid ON
×: Solenoid OFF
–: Non-standard condition
Line Pressure Solenoid Valve
If non-standard solenoid signal is sent to TCM, line pressure solenoid valve is turned OFF to achieve maxi-
mum oil pressure.
Torque Converter Clutch Solenoid Valve
Actual lever position PNP switch input signal Running status
“P” “P” position and other position signals P
“R” “R” position and other position signals R
“N” “N” position and other position signals N
“D” “D” position and other position signals D
1⇔D2⇔D3⇔D4
“2”“2” position and other position signals (Except “1” position) 21⇔22⇔23
“2” position and “1” position signals 21⇔22
“1”“1” position and other position signals (Except “2” position) 11⇔12⇔13
“1” position and “2” position signals 11⇔12
Shift positionNormalMalfunction in solenoid
valve AMalfunction in solenoid
valve BMalfunction in solenoid
valves A and B
A BGearABGearABGearABGear
“D” position●●1st –●→×
3rd ●→×–
3rd ––
3rd ×●2nd –●→× ×–––
××3rd – x×–––
●×4th – x●→×–––
“2” position●●1st –●→×●→×–––
×●2nd –●→× ×–––
××3rd – x×–––
“1” position●●1st –●→×●→×–––
×●2nd –●→× ×–––
××3rd – x×–––
SYSTEM SYMPTOM
TM-435
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Slips/Will Not EngageVehicle will not run in
“D”, “1”, “2” positions
(but runs in R posi-
tion). Clutch slips.
Very poor accelera-
tion.ON vehicle1. A/T fluid levelXX-XX, "*****"
2. Stall testTM-175
3. Line pressure testTM-178
4. Line pressure solenoid valveXX-XX, "*****"
5. Control valve assemblyXX-XX, "*****"
6. Accumulator N-DXX-XX, "*****"
OFF vehicle7. Reverse clutchXX-XX, "*****"
8. High clutchXX-XX, "*****"
9. Forward clutchXX-XX, "*****"
10. Forward one-way clutchXX-XX, "*****"
11. Low one-way clutchXX-XX, "*****"
Clutches or brakes
slip somewhat in start-
ing.ON vehicle1. A/T fluid levelXX-XX, "*****"
2. Control cable adjustmentXX-XX, "*****"
3. Accelerator pedal position sensorEC-583
4. Line pressure testTM-178
5. Line pressure solenoid valveXX-XX, "*****"
6. Control valve assemblyXX-XX, "*****"
7. Accumulator N-DXX-XX, "*****"
OFF vehicle8. Forward clutchXX-XX, "*****"
9. Reverse clutchXX-XX, "*****"
10. Low & reverse brakeXX-XX, "*****"
11. Oil pumpXX-XX, "*****"
12. Torque converterXX-XX, "*****"
No creep at all.
XX-XX, "*****"
, XX-
XX, "*****"
ON vehicle1. A/T fluid levelXX-XX, "*****"2. Line pressure testTM-178
3. Control valve assemblyXX-XX, "*****"
OFF vehicle4. Forward clutchXX-XX, "*****"5. Oil pumpXX-XX, "*****"
6. Torque converterXX-XX, "*****"
Almost no shock or
clutches slipping in
change from D
1 to D2.ON vehicle1. A/T fluid levelXX-XX, "*****"
2. Accelerator pedal position sensorEC-583
3. Line pressure testTM-178
4. Accumulator servo releaseXX-XX, "*****"
5. Control valve assemblyXX-XX, "*****"
OFF vehicle 6. Brake bandXX-XX, "*****"
Items Symptom Condition Diagnostic item Reference page