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DTC P0734 A/T 4TH GEAR FUNCTION
Description INFOID:0000000004305383
• 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 shif t 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 c ontrol valve sticking, improper solenoid valve operation,
malfunctioning oil pump or torque converter clutch, etc.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004305384
Remarks: Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004305385
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0734 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 checki ng 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 pos ition (4th) supposed by TCM, the slip ratio will be much
less than normal. In case the ratio does not reach t he specified value, TCM judges this diagnosis malfunc-
tion.
This malfunction will be caused when shift solenoid valve A is stuck open or 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
*: “P0734 A/T 4TH GR FNCTN” is detected.
Possible Cause INFOID:0000000004305386
• Shift solenoid valve A
• Shift solenoid valve B
• Line pressure solenoid valve
• Each clutch
• Hydraulic control circuit
DTC Confirmation Procedure INFOID:0000000004305387
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. 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 DTY Small throttle opening (Low line pressure)
⇔ Large
throttle opening (High line pressure) 0%
⇔ 94%

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DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
Description INFOID:0000000004305397
• 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 shif t 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 c ontrol valve sticking, improper solenoid valve operation,
malfunctioning oil pump or torque converter clutch, etc.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004305398
Remarks: Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004305399
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0744 A/T TCC S/V FNCTN” wi th CONSULT-III is detected when A/T cannot per-
form lock-up even if electrical circuit is good.
• This diagnosis monitors actual gear position by checki ng 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 pos ition (4th) supposed by TCM, the slip ratio will be much
less than normal. In case the ratio does not reach t he 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 stu ck closed: 1, 2, 2 and 1* positions to each gear position
above
*: “P0744 A/T TCC S/V FNCTN” is detected.
Possible Cause INFOID:0000000004305400
• Line pressure solenoid valve
• Torque converter clutch solenoid valve
• Each clutch
• Hydraulic control circuit
DTC Confirmation Procedure INFOID:0000000004305401
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” m ode 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 - 1.5 V
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 & SR T CONFIRMATION” mode for “TRANSMISSION” with
CONSULT-III and touch “START”.
Item name Condition Display value (Approx)
TCC S/V DUTY Lock-up OFF ⇔ Lock-up ON 4% ⇔ 94%

DTC BATT/FLUID TEMP SEN (A/T FLU
ID TEMP SENSOR CIRCUIT AND TCM
POWER SOURCE)
AT-161
< SERVICE INFORMATION >
D
E
F
G H
I
J
K L
M A
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OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. 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 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 AT-221, " Control Valve Assembly and Accumulators " .
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 AT-157, " DTC Confirmation Procedure " .
OK or NG OK >>
INSPECTION END
NG >> GO TO 10. 10.
CHECK TCM
1. Check TCM input/output signal. Refer to AT-77, " TCM Terminal and Reference Value " .
2. If NG, recheck TCM pin terminals for dam age or loose connection with harness connector.
OK or NG OK >>
INSPECTION END
NG >> Repair or replace damaged parts.
Component Inspection INFOID:0000000004305449
A/T FLUID TEMPERATURE SENSOR Item Connector Terminal
Temperature
[° C ( °F)] Resistance
(Approx.)
A/T fluid tem-
perature sensor F30 6 - 7 AT-379, " A/T Fluid Temperature
Sensor "
SCIA4948E
Item Connector Terminal
Temperature
[° C ( °F)] Resistance
(Approx.)
A/T fluid tem-
perature sensor F30 6 - 7 AT-379, " A/T Fluid Temperature
Sensor "
SCIA7831E

AT-162< SERVICE INFORMATION >
DTC BATT/FLUID TEMP SEN (A/T FLU
ID TEMP SENSOR CIRCUIT AND TCM
POWER SOURCE)
• Remove oil pan. Refer to AT-221, " Control Valve Assembly and
Accumulators " .
• Check resistance between terminal cord assembly harness con-
nector terminals while changing temperature as shown.
Item Connector Terminal Temperature
[° C ( °F)] Resistance
(Approx.)
A/T fluid tem-
perature sensor F30 6 - 7 AT-379, " A/T Fluid Temperature
Sensor "
SCIA7831E

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OK or NG OK >> GO TO 5.
NG >> GO TO 4. Disassembly " .
2. Check the following items:
- Forward clutch assembly. Refer to AT-306, " Forward and Overrun Clutches " .
- Overrun clutch assembly. Refer to AT-306, " Forward and Overrun Clutches " .
- Reverse clutch assembly. Refer to AT-296, " Reverse Clutch " .
OK or NG OK >> GO TO 5.
NG >> Repair or replace damaged parts. Check at Idle " .
OK or NG OK >>
INSPECTION END
NG >> GO TO 6. TCM Terminal and Reference Value " .
2. If NG, recheck TCM pin terminals for dam age or loose connection with harness connector.
OK or NG OK >>
INSPECTION END
NG >> Repair or replace damaged parts.
Large Shock "N" → "R" Position INFOID:0000000004305476
SYMPTOM: There is a large shock when changing from “N” to “R” position.
DIAGNOSTIC PROCEDURE CONSULT-III Functi
on (TRANSMISSION) " or
AT-83, " Diagnosis Pro-
cedure without CONSULT-III " .
Is any malfunction detected by self-diagnostic results? YES >> Check the malfuncti
oning system. Refer to AT-79, " CONSULT-III Functi
on (TRANSMISSION) " or
AT-83, " Diagnosis Procedure without CONSULT-III " .
NO >> GO TO 2. Inspections Before Trouble
Diagnosis " .
OK or NG OK >> GO TO 4.
NG >> GO TO 3. Control Valve Assembly and Accumulators " .
2. Check the following items:
- Valves to control line pressure (Pressure regulator valv e, pressure modifier valve, pilot valve and pilot fil-
ter)
- Line pressure solenoid valve
- Oil pump assembly. Refer to AT-277, " Oil Pump " .
OK or NG OK >> GO TO 4.

Check at Idle " .
OK or NG OK >>
INSPECTION END
NG >> GO TO 5. TCM Terminal 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.
Vehicle Does Not Creep Ba ckward in "R" Position INFOID:0000000004305477
SYMPTOM:
Vehicle does not creep backward when selecting “R” position.
DIAGNOSTIC PROCEDURE Checking A/T Fluid " .
OK or NG OK >> GO TO 2.
NG >> Refill ATF. Inspections Before Trouble
Diagnosis " .
OK or NG OK >> GO TO 4.
NG >> GO TO 3. Control Valve Assembly and Accumulators " .
2. Check the following items:
- Valves to control line pressure (Pressure regulator valve, pressure modifier valve, pilot valve and pilot fil- ter)
- Line pressure solenoid valve
3. Disassemble A/T. Refer to AT-256, " Disassembly " .
4. Check the following item:
- Oil pump assembly. Refer to AT-277, " Oil Pump " .
OK or NG OK >> GO TO 4.
NG >> Repair or replace damaged parts. Inspections Before Trouble
Diagnosis " .
OK or NG OK >> GO TO 6.
OK in “1” position, NG in “R” position>>GO TO 5.
NG in both “1” and “R” positions>>GO TO 7. Disassembly " .

Control Valve Assembly and Accumulators " .
2. Check the following items:
- Valves to control line pressure (Pressure regulator valve, pressure modifier valve, pilot valve and pilot fil- ter)
- Line pressure solenoid valve
3. Disassemble A/T. Refer to AT-256, " Disassembly " .
4. Check the following item:
- Oil pump assembly. Refer to AT-277, " Oil Pump " .
OK or NG OK >> GO TO 4.
NG >> Repair or replace damaged parts. Inspections Before Trouble Diagno-
sis " .
OK or NG OK >> GO TO 6.
NG >> GO TO 5. Disassembly " .
2. Check the following items:
- Oil pump assembly. Refer to AT-277, " Oil Pump " .
- Forward clutch assembly. Refer to AT-306, " Forward and Overrun Clutches " .
- Forward one-way clutch. Refer to AT-317, " Rear Internal Gear and Forward Clutch Hub " .
- Low one-way clutch. Refer to AT-256, " Disassembly " .
- Torque converter. Refer to AT-256, " Disassembly " .
OK or NG OK >> GO TO 7.
NG >> Repair or replace damaged parts. Component " .
2. Check A/T fluid condition. Refer to AT-51, " Inspections Before Trouble Diagnosis " .
OK or NG OK >> GO TO 7.
NG >> GO TO 5. Check at Idle " .
OK or NG OK >>
INSPECTION END
NG >> GO TO 8. TCM Terminal 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.
Vehicle Cannot Be Started from D 1 INFOID:0000000004305479
SYMPTOM:
Vehicle cannot be started from D 1 on “Cruise Test — Part 1”.

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DIAGNOSTIC PROCEDURE Check at Idle " .
Is “ Vehicle Dose Not Creep Backward in “ R ” Position ” OK?
OK >> GO TO 2.
NG >> Go to AT-186, " Vehicle Does Not Creep Backward in "R" Position " .
CONSULT-III Functi
on (TRANSMISSION) " or
AT-83, " Diagnosis Pro-
cedure without CONSULT-III " .
Is any malfunction detected by self-diagnostic results? YES >> Check the malfuncti
oning system. Refer to AT-79, " CONSULT-III Functi
on (TRANSMISSION) " or
AT-83, " Diagnosis Procedure without CONSULT-III " .
NO >> GO TO 3. Description " (HR16DE),
EC-959, " Component
Description " (MR Type 1) or
EC-1481, " Component Description " (MR Type 2).
OK or NG OK >> GO TO 4.
NG >> Repair or replace accelerator pedal position sensor. Inspections Before Trou-
ble Diagnosis " .
OK or NG OK >> GO TO 6.
NG >> GO TO 5. Control Valve Assembly and Accumulators " .
2. Check the following items:
- Shift valve A
- Shift valve B
- Shift solenoid valve A
- Shift solenoid valve B
- Pilot valve
- Pilot filter
3. Disassemble A/T. Refer to AT-256, " Disassembly " .
4. Check the following items:
- Forward clutch assembly. Refer to AT-306, " Forward and Overrun Clutches " .
- Low one-way clutch. Refer to AT-256, " Disassembly " .
- Forward one-way clutch. Refer to AT-317, " Rear Internal Gear and Forward Clutch Hub " .
- High clutch assembly. Refer to AT-301, " High Clutch " .
- Torque converter. Refer to AT-256, " Disassembly " .
- Oil pump assembly. Refer to AT-277, " Oil Pump " .
OK or NG OK >> GO TO 8.
NG >> Repair or replace damaged parts. Component " .
2. Check A/T fluid condition. Refer to AT-51, " Inspections Before Trouble Diagnosis " .
OK or NG OK >> GO TO 7.
NG >> GO TO 5.