Nissan Altima 2007-2012 Service Manual: P0744 A/T TCC S/V function (lock -up)

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 malfunction (circuits open or shorted), but also by mechanical malfunction 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. NOTE: If “DTC CONFIRMATION PROCEDURE” has been previously performed, always turn ignition switch OFF.

Then wait at least 10 seconds before performing the next test.

1.CHECK DTC DETECTION

1. Turn ignition switch ON.

2. Select “DATA MONITOR”.

3. Start engine and maintain the following condition for at least 30 seconds.

Follow the procedure “With CONSULT-III”.

Is “P0744 A/T TCC S/V FNCTN” detected? YES >> Go to TM-327, "Diagnosis Procedure".

NO >> Check intermittent incident. Refer to GI-42, "Intermittent Incident".

Diagnosis Procedure

1.CHECK LINE PRESSURE

Perform line pressure test. Refer to TM-423, "Inspection and Judgment".

Is the inspection result normal? YES >> GO TO 2.

NO >> Repair or replace damaged parts.

2.CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE

1. Turn ignition switch OFF.

2. Disconnect CVT unit connector.

3. Check torque converter clutch solenoid valve. Refer to TM-328, "Component Inspection (Torque Converter Clutch Solenoid Valve)".

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 TM-328, "Component Inspection (Lock-up Select Solenoid Valve)".

Is the inspection result normal? YES >> GO TO 4.

NO >> Replace transaxle assembly. Refer to TM-447, "Exploded View".

4.CHECK OUTPUT SPEED SENSOR (SECONDARY SPEED SENSOR) SYSTEM

Check output speed sensor (secondary speed sensor) system. Refer to TM-318, "DTC Logic".

Is the inspection result normal? YES >> GO TO 5.

NO >> Repair or replace damaged parts.

5.CHECK INPUT SPEED SENSOR (PRIMARY SPEED SENSOR) SYSTEM

Check input speed sensor (primary speed sensor) system. Refer to TM-313, "DTC Logic".

Is the inspection result normal? YES >> GO TO 6.

NO >> Repair or replace damaged parts.

6.DETECT MALFUNCTIONING ITEMS

Check TCM connector pin terminals for damage or loose connection with harness connector.

Is the inspection result normal? YES >> Replace TCM. Refer to TM-430, "Exploded View".

NO >> Repair or replace damaged parts.

Component Inspection (Torque Converter Clutch Solenoid Valve)

1.CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE

Check resistance between CVT unit terminal 12 and ground.

Is the inspection result normal? YES >> INSPECTION END

NO >> Perform “SELF-DIAG RESULTS” mode for “TRANSMISSION”.

Component Inspection (Lock-up Select Solenoid Valve)

1.CHECK LOCK-UP SELECT SOLENOID VALVE

Check resistance between CVT unit terminal 13 and ground.

Is the inspection result normal? YES >> INSPECTION END

NO >> Replace transaxle assembly. Refer to TM-447, "Exploded View".

    P0740 torque converter clutch solenoid valve
    Description • The torque converter clutch solenoid valve is activated by the TCM in response to signals sent from the vehicle speed and accelerator pedal position sensors. Lock-up piston operat ...

    P0745 line pressure solenoid valve
    Description The pressure control solenoid valve A (line pressure solenoid valve) regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the TCM. ...

    Other materials:

    Mechanical system
    Cross-Sectional View 1. Converter housing 2. Driven sprocket 3. Chain 4. Reverse brake 5. Oil pump 6. Forward clutch 7. Planetary carrier 8. Primary pulley 9. Sun gear 10. Steel belt 11. Side cover 12. Internal gear 13. Parking gear 14. Secondary pulley 15. Final gear 16. Differen ...

    Tweeter (sedan)
    Description The audio unit sends audio signals to the BOSE speaker amp. The BOSE speaker amp. amplifies the audio signals before sending them to the tweeters using the audio signal circuits. Diagnosis Procedure 1.HARNESS CHECK 1. Disconnect BOSE speaker amp. connector B122 and suspect tweet ...

    None of the power windows can be operated using any switch
    Diagnosis Procedure 1. CHECK BCM POWER SUPPLY AND GROUND CIRCUIT Check BCM power supply and ground circuit. Refer to BCS-42, "Diagnosis Procedure". Is the inspection result normal? YES >> GO TO 2 NO >> Repair or replace the malfunctioning parts. 2. CHECK MAIN POWER ...