Infiniti F50. Manual - part 60

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)

AT-125

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4. 

CHECK POWER SOURCE CIRCUIT

1.

Turn ignition switch to “OFF” position.

2.

Disconnect TCM connector.

3.

Check continuity between A/T unit assembly harness connector
and TCM connector.

4.

If OK, check harness for short to ground and short to power.

5.

Reinstall any part removed.

OK or NG

OK

>> GO TO 5.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

5. 

CHECK DTC

Perform “DTC Confirmation Procedure”. Refer to 

AT-117, "DTC Confirmation Procedure"

 .

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 6.

6. 

PERFORM TCM INSPECTION

1.

Perform TCM input/output signal inspection.

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.

Component Inspection

ECS00A1L

TORQUE CONVERTER CLUTCH SOLENOID VALVE
Resistance check

1.

Turn ignition switch “OFF”.

2.

Remove oil pan. Refer to 

AT-289, "Control Valve Assembly"

 .

3.

Disconnect control valve assembly harness connector.

4.

Check resistance between terminal and ground.

5.

If NG, replace control valve assembly. Refer to 

AT-289, "Control

Valve Assembly"

 .

Item

Connector No.

Terminal No. (Wire color)

Continuity

TCM

F103

20 (Y)

Yes

A/T unit assembly 
harness connector

F27

8 (Y)

SCIA1831E

Solenoid Valve

Connector No.

Terminal No. 

(Wire color)

Resistance (

Ω

) 

(Approx.)

Torque converter clutch 
solenoid valve

F301

11 (BR) - Ground

3 - 9 

Ω

SCIA3061E

AT-126

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)

Operation check

●

Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminal 11 and ground.

SCIA3105E

DTC P0745 LINE PRESSURE SOLENOID VALVE

AT-127

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DTC P0745 LINE PRESSURE SOLENOID VALVE

PFP:31940

Description

ECS0084S

The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in
response to a signal sent from the TCM.
The line pressure duty cycle value is not consistent when the closed throttle position signal is “ON”.
To confirm the line pressure duty cycle at low pressure, the accelerator (throttle) should be open until
the closed throttle position signal is “OFF”.

On Board Diagnosis Logic

ECS0084T

●

This is an OBD-II self-diagnostic item.

●

Diagnostic trouble code “L/PRESS SOL/CIRC” with CONSULT-II or P0745 without CONSULT-II is
detected under the following conditions.

–

When TCM detects an improper voltage drop when it tries to operate the solenoid valve.

–

When TCM detects as irregular by comparing target value with monitor value.

Possible Cause

ECS0084U

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Harness or connectors
(The solenoid circuit is open or shorted.)

●

Line pressure solenoid valve

DTC Confirmation Procedure

ECS0084V

NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF”
and wait at least 10 seconds before conducting the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.

 WITH CONSULT-II

1.

Turn ignition switch to “ON” position and select “DATA MONI-
TOR” mode for “ENGINE” with CONSULT-II.

2.

Engine start and wait at least 5 second.

3.

If DTC is detected, go to “

AT-129, "Diagnostic Procedure"

 .

 WITH GST

Follow the procedure “With CONSULT-II”.

SAT014K

AT-128

DTC P0745 LINE PRESSURE SOLENOID VALVE

Wiring Diagram — AT — LPSV

ECS0084W

TCM terminal and data are reference value. Measured between each terminal and ground.

TCWM0007E

Terminal   

No.

Wire 

color

Item

Condition

Data (Approx.)

1

B/Y

Line pressure 
solenoid valve

IGN ON

After warming up the engine, release your foot from the 
accelerator pedal.

2V

After warming up the engine, press the accelerator pedal 
all the way down.

0.7V