P0744

P0744 TORQUE CONVERTER

Description

This malfunction is detected when the torque converter clutch does not lock-up as instructed by the TCM. This is not only caused by electrical malfunctions (circuits open or shorted), but also by mechanical malfunctions such as control valve sticking, improper solenoid valve operation, etc.


DTC Logic


DTC DETECTION LOGIC







DTC CONFIRMATION PROCEDURE


CAUTION:
Always drive vehicle at a safe speed.

1. PRECONDITIONING

If "DTC CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
- GO TO 2.

2. CHECK DTC DETECTION

With CONSULT
1.Start the engine.
2.Warm up the engine. [Set the CVT fluid to 20�C (68�F) or more.]
NOTE:
When the ambient temperature is 20�C (68�F), the CVT fluid usually increases to 50 to 80�C (122 to
176�F) with driving in an urban area for approximately 10 minutes.
3.Maintain the following condition for at least 30 seconds.





With GST
Follow the procedure "With CONSULT".
Is "P0744" detected?
YES- Go to "Diagnosis Procedure" .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK LINE PRESSURE

Perform line pressure test. Refer to "Work Procedure" Line Pressure Test.
Is the inspection result normal?
YES- GO TO 2.
Revision: March 20122013 Infiniti JX
NO- Repair or replace damaged parts.

2. CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE

Check torque converter clutch solenoid valve. Refer to "Diagnosis Procedure" P0740.
Is the inspection result normal?
YES- GO TO 3.
NO- Repair or replace damaged parts.

3. CHECK LOCK-UP SELECT SOLENOID VALVE

Check lock-up select solenoid valve. Refer to "Diagnosis Procedure" P1740.
Is the inspection result normal?
YES- GO TO 4.
NO- Repair or replace damaged parts.

4. CHECK SECONDARY SPEED SENSOR SYSTEM

Check secondary speed sensor system. Refer to "Diagnosis Procedure" P0720.
Is the inspection result normal?
YES- GO TO 5.
NO- Repair or replace damaged parts.

5. CHECK PRIMARY SPEED SENSOR SYSTEM

Check primary speed sensor system. Refer to "Diagnosis Procedure" P0715.
Is the inspection result normal?
YES- GO TO 6.
NO- Repair or replace damaged parts.

6. CHECK DTC

With CONSULT
1.Perform "DTC CONFIRMATION PROCEDURE". Refer to "DTC Index" A L L Diagnostic Trouble Codes ( DTC ).
2.Check DTC.
Is "P0744" displayed?
YES- Replace transaxle assembly. Refer to "Removal and Installation" Removal and Installation.
NO- Check intermittent incident. Refer to "Intermittent Incident" Intermittent Incident.
Revision: March 20122013 Infiniti JX