Infiniti QX56 (Z62). Manual - part 1305

P0744 TORQUE CONVERTER

TM-129

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B]

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P0744 TORQUE CONVERTER

Description

INFOID:0000000006226838

This malfunction is detected when the A/T does not lock-up. This is not only caused by electrical malfunction
(circuits open or shorted) but also by mechanical malfunction such as control valve sticking, improper solenoid
valve operation, etc.

DTC Logic

INFOID:0000000006226839

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” is previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

 With CONSULT-III

1.

Start the engine. 

2.

Select “MANU MODE SW”, “GEAR” and “VEHICLE SPEED” in “Data Monitor” in “TRANSMISSION”.

3.

Drive vehicle and maintain the following conditions for 10 seconds or more.
NOTE:
Driving the vehicle uphill (increased engine load) will help maintain the driving conditions required for this
test.

4.

Perform “Self Diagnostic Results” in “TRANSMISSION”.

 With GST

Follow the procedure “With CONSULT-III”.
Is “P0744” detected?

YES

>> Go to 

TM-129, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006226840

1.

DETECT MALFUNCTIONING ITEM

Disassemble the A/T assembly to check component parts. Refer to 

TM-226, "Disassembly"

.

NOTE:
Check the component parts, referring to “Possible cause” in “DTC DETECTION LOGIC”. Refer to 

TM-129,

"DTC Logic"

.

Is the inspection result normal?

YES

>> Replace the control valve & TCM. Refer to 

TM-182, "Exploded View"

.

DTC

Trouble diagnosis name

DTC is detected if...

Possible cause

P0744

Torque Converter Clutch Circuit 
Intermittent

The lock-up is not performed in 
spite of within the lock-up area.

• Harness or connectors
• Torque converter clutch sole-

noid valve

• Torque converter
• Input speed sensor 1, 2
• Hydraulic control circuit

MANU MODE SW

: ON

GEAR

: 2nd

VEHICLE SPEED

: 40 km/h (25 MPH) or more

TM-130

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B]

P0744 TORQUE CONVERTER

NO

>> Repair or replace damaged parts.

P0745 PRESSURE CONTROL SOLENOID A

TM-131

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B]

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P0745 PRESSURE CONTROL SOLENOID A

DTC Logic

INFOID:0000000006226841

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” is previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

 With CONSULT-III

1.

Start the engine.

2.

Wait for 5 seconds or more at idle speed in “N” position.

3.

Perform “Self Diagnostic Results” in “TRANSMISSION”.

 With GST

Follow the procedure “With CONSULT-III”.

Is “P0745” detected?

YES

>> Go to 

TM-131, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006226842

1.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace the control valve & TCM. Refer to 

TM-182, "Exploded View"

.

NO

>> Repair or replace damaged parts.

DTC

Trouble diagnosis name

DTC is detected if...

Possible cause

P0745

Pressure Control Solenoid A

The line pressure solenoid 
valve monitor value is 0.4 A or 
less when the line pressure so-
lenoid valve command value is 
more than 0.75 A.

• Harness or connectors

(Solenoid valve circuit is 
open or shorted.)

• Line pressure solenoid valve

TM-132

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B]

P0750 SHIFT SOLENOID A

P0750 SHIFT SOLENOID A

DTC Logic

INFOID:0000000006226843

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” is previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

 With CONSULT-III

1.

Start the engine. 

2.

Select “BATTERY VOLT”, “MANU MODE SW”, “GEAR” and “VHCL/S SE-A/T” in “Data Monitor” in
“TRANSMISSION”.

3.

Drive vehicle and maintain the following conditions for 5 seconds or more.

4.

Perform “Self Diagnostic Results” in “TRANSMISSION”.

 With GST

Follow the procedure “With CONSULT-III”.
Is “P0750” detected?

YES

>> Go to 

TM-132, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006226844

1.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace the control valve & TCM. Refer to 

TM-182, "Exploded View"

.

NO

>> Repair or replace damaged parts.

DTC

Trouble diagnosis name

DTC is detected if...

Possible cause

P0750

Shift Solenoid A

• The anti-interlock solenoid 

valve monitor value is ON 
when the anti-interlock sole-
noid valve command value is 
OFF.

• The anti-interlock solenoid 

valve monitor value is OFF 
when the anti-interlock sole-
noid valve command value is 
ON.

• Harness or connectors

(Solenoid valve circuit is 
open or shorted.)

• Anti-interlock solenoid valve

BATTERY VOLT

: 9 V or more

MANU MODE SW

: ON

GEAR

: 1st

VHCL/S SE-A/T

: 10 km/h (7 MPH) or more