Nissan Frontier D22. Manual - part 83

DTC P0744 IMPROPER LOCK-UP OPERATION

AT-301

[RE4R01A]

D

E

F

G

H

I

J

K

L

M

A

B

AT

Wiring Diagram — AT — TCCSIG

ECS007N4

WCWA0100E

AT-302

[RE4R01A]

DTC P0744 IMPROPER LOCK-UP OPERATION

Diagnostic Procedure

ECS007N5

1. 

CHECK SHIFT UP (D

3

  TO D

4

 )

During 

AT-223, "Cruise Test — Part 1"

 , does A/T shift from D

3

  to D

4

at the specified speed?

Yes or No

Yes

>> Check for proper lock-up. GO TO 10.

No

>> GO TO 2.

2. 

CHECK LINE PRESSURE

Perform line pressure test. Refer to 

AT-214, "Line Pressure Test"

 .

OK or NG

OK

>> GO TO 3.

NG

>> GO TO 6.

3. 

CHECK CONTROL VALVE

1.

Disassemble control valve assembly. Refer to 

AT-431, "CONTROL VALVE ASSEMBLY"

 .

2.

Check to ensure that:

–

Valve, sleeve and plug slide along valve bore under their own weight.

–

Valve, sleeve and plug are free from burrs, dents and scratches.

–

Control valve springs are free from damage, deformation and fatigue.

–

Hydraulic line is free from obstacles.

OK or NG

OK

>> GO TO 4.

NG

>> Repair control valve.

4. 

CHECK SHIFT UP (D

3

  TO D

4

 )

Does A/T shift from D

3

  to D

4

  at the specified speed?

Yes or No

Yes

>> GO TO 5.

No

>> Check control valve again. Repair or replace control valve assembly.

5. 

CHECK DTC

Perform Diagnostic Trouble Code (DTC) confirmation procedure. Refer to 

AT-299, "DIAGNOSTIC TROUBLE

CODE (DTC) CONFIRMATION PROCEDURE"

 .

OK or NG

OK

>> INSPECTION END.

NG

>>

●

Check for proper lock-up. GO TO 10.

SAT988H

SAT367H

DTC P0744 IMPROPER LOCK-UP OPERATION

AT-303

[RE4R01A]

D

E

F

G

H

I

J

K

L

M

A

B

AT

6. 

CHECK LINE PRESSURE SOLENOID VALVE

1.

Remove control valve assembly. Refer to 

AT-402, "REMOVAL"

 .

2.

Check line pressure solenoid valve operation. Refer to 

AT-304, "SOLENOID VALVES"

 .

OK or NG

OK

>> GO TO 7.

NG

>> Replace solenoid valve assembly.

7. 

CHECK CONTROL VALVE

1.

Disassemble control valve assembly. Refer to 

AT-431, "CONTROL VALVE ASSEMBLY"

 .

2.

Check line pressure circuit valves for sticking.

–

Pressure regulator valve

–

Pilot valve

–

Pressure modifier valve

OK or NG

OK

>> GO TO 8.

NG

>> Repair control valve.

8. 

CHECK SHIFT UP (D

3

  TO D

4

 )

Does A/T shift from D

3

  to D

4

  at the specified speed?

Yes or No

Yes

>> GO TO 9.

No

>> Check control valve again. Repair or replace control valve assembly.

9. 

CHECK DTC

Perform Diagnostic Trouble Code (DTC) confirmation procedure. Refer to 

AT-299, "DIAGNOSTIC TROUBLE

CODE (DTC) CONFIRMATION PROCEDURE"

 .

OK or NG

OK

>> INSPECTION END.

NG

>>

●

Check for proper lock-up. GO TO 10.

10. 

CHECK LOCK-UP CONDITION

During 

AT-223, "Cruise Test — Part 1"

 ,

Does A/T perform lock-up at the specified speed?
Yes or No

Yes

>> Perform “Cruise Test 

− Part 1” again and return to the start point of this flow chart.

No

>> GO TO 11.

11. 

CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE

1.

Remove control valve assembly. Refer to 

AT-402, "REMOVAL"

 .

2.

Check torque converter clutch solenoid valve operation.
Refer to 

AT-297, "TORQUE CONVERTER CLUTCH SOLENOID VALVE"

 .

OK or NG

OK

>> GO TO 12.

NG

>> Replace solenoid valve assembly.

SAT367H

AT-304

[RE4R01A]

DTC P0744 IMPROPER LOCK-UP OPERATION

12. 

CHECK CONTROL VALVE

1.

Disassemble control valve assembly. Refer to 

AT-431, "CONTROL VALVE ASSEMBLY"

 .

2.

Check control valves for sticking.

–

Torque converter clutch control valve

–

Torque converter clutch relief valve

OK or NG

OK

>> GO TO 13.

NG

>> Repair control valve.

13. 

CHECK LOCK-UP CONDITION

Does A/T perform lock-up at the specified speed?

Yes or No

Yes

>> GO TO 14.

No

>> Check control valve again. Repair or replace control valve assembly.

14. 

CHECK DTC

Perform Diagnostic Trouble Code (DTC) confirmation procedure. Refer to 

AT-299, "DIAGNOSTIC TROUBLE

CODE (DTC) CONFIRMATION PROCEDURE"

 .

OK or NG

OK

>> INSPECTION END.

NG

>> Perform “Cruise Test — Part 1” again and return to the start point of this flow chart.

Component Inspection

ECS007N6

SOLENOID VALVES

●

For removal, refer to 

AT-402, "REMOVAL"

 .

SAT367H

AAT614A