Infiniti M45 (Y34). Manual - part 60

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE

AT-125

D

E

F

G

H

I

J

K

L

M

A

B

AT

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

Diagnostic Procedure

ACS0047Q

1. 

CHECK INPUT SIGNALS

 With CONSULT-II

1.

Start engine.

2.

Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T” with CONSULT-II.

3.

Read out the value of “TCC SOLENOID” while driving.
Check the value changes according to driving speed.

 Without CONSULT-II

1.

Start engine.

2.

Check voltage between TCM connector and ground.

OK or NG

OK >> GO 

TO 

6.

NG

>> GO TO 2.

2. 

CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect A/T unit assembly harness connector at the trans-
mission right side.

3.

Check the resistance between terminal and ground.

OK or NG

OK >> GO 

TO 

5.

NG

>> GO TO 3.

Terminal   

No.

Wire 

color

Item

Condition

Data (Approx.)

20

Y

TCC solenoid 
valve

When   

vehicle 
cruises

When lock-up

More than 2V 

When not lock-up

0V

Item name

Condition 

Display value (Approx.)

TCC SOLENOID

When perform slip lock-
up

0.2 - 0.4A

When perform lock-up

0.4 - 0.6A

SCIA4462E

Item

 Connec-

tor No.

 Terminal 

No.

 Condition

Data 

(Approx.)

TCC sole-
noid valve

 F103

 20 (Y) - 

Ground

When lock-up

More than 

2V 

When not lock-up

0V

SCIA4464E

Solenoid valve

Connector No.

Terminal No. 

Resistance (Approx.) 

Torque converter clutch 
solenoid valve

F27

8 - Ground

3 - 9 

Ω

SCIA1830E

AT-126

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE

3. 

CHECK TERMINAL CORD ASSEMBLY

1.

Remove oil pan. Refer to 

AT-312, "Control Valve Assembly"

 .

2.

Disconnect A/T unit assembly harness connector and control valve assembly harness connector.

3.

Check continuity between A/T unit assembly harness connector
and control valve assembly harness 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 4.

NG

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

4. 

CHECK VALVE RESISTANCE

Check valve resistance

●

Refer to 

AT-127, "Component Inspection"

 .

OK or NG

OK >> GO 

TO 

6.

NG

>> Replace the control valve assembly. Refer to 

AT-312, "Control Valve Assembly"

 .

5. 

CHECK POWER SOURCE CIRCUIT

1.

Turn ignition switch OFF.

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 6.

NG

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

6. 

CHECK DTC

Perform “DTC Confirmation Procedure”. Refer to 

AT-123, "DTC Confirmation Procedure"

 .

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 7.

Item

Connector No.

Terminal No. (Wire color)

Continuity

A/T unit assembly 
harness connector

F27

8 (R/B)

Yes

Control valve assem-
bly harness connec-
tor

F301

11 (R/B)

SCIA3060E

Item

Connector No.

Terminal No. (Wire color)

Continuity

TCM

F103

20 (Y)

Yes

A/T unit assembly 
harness connector

F27

8 (Y)

SCIA1831E

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE

AT-127

D

E

F

G

H

I

J

K

L

M

A

B

AT

7. 

CHECK TCM

1.

Check TCM input/output signal. Refer to 

AT-86, "TCM Input/Output Signal Reference Values"

 .

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

ACS0047R

TORQUE CONVERTER CLUTCH SOLENOID VALVE
Resistance Check

1.

Turn ignition switch OFF.

2.

Remove oil pan. Refer to 

AT-312, "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-312, "Control

Valve Assembly"

 .

Operation Check

●

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

Solenoid Valve

Connector No.

Terminal No. 

(Wire color)

Resistance 

(Approx.)

Torque converter clutch 
solenoid valve

F301

11 (BR) - Ground

3 - 9 

Ω

SCIA3061E

SCIA3105E

AT-128

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

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

PFP:31940

Description

ACS0047S

This malfunction is detected when the A/T does not shift into 5th gear position or 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.

CONSULT-II Reference Value

ACS004P3

On Board Diagnosis Logic

ACS0047T

●

This is an OBD-II self-diagnostic item.

●

Diagnostic trouble code “A/T TCC S/V FNCTN” with CONSULT-II or P0744 without CONSULT-II is
detected under the following conditions.

–

When A/T cannot perform lock-up even if electrical circuit is good.

–

When TCM detects as irregular by comparing difference value with slip rotation.

Possible Cause

ACS0047U

●

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

●

Torque converter clutch solenoid valve

●

Hydraulic control circuit

DTC Confirmation Procedure

ACS0047V

CAUTION:

Always drive vehicle at a safe speed.

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.

Start engine and select “TCC S/V FNCTN CHECK” of “DTC
WORK SUPPORT” mode for “A/T” with CONSULT-II and touch
“START”.

2.

Accelerate vehicle to more than 80 km/h (50 MPH) and maintain
the following condition continuously until “TESTING” has turned
to “COMPLETE”. (It will take approximately 30 seconds after
“TESTING” shows.)
ACCELE POSI: More than 1.0/8 (at all times during step 4)
TCC SOLENOID: 0.4 - 0.6 A
Selector lever: “D” position 
[Reference speed: Constant speed of more than 80 km/h (50
MPH)]

–

Check that “GEAR” shows “5”.

–

For shift schedule, refer to 

AT-62, "Vehicle Speed When Performing and Releasing Complete Lock-

Up"

 .

–

If “TESTING” does not appear on CONSULT-II for a long time, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0744 is shown, refer to applicable “TROUBLE DIAGNOSIS FOR
DTC”.

3.

Make sure that “OK” is displayed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to 

AT-131, "Diagnostic Procedure"

 .

Refer to shift schedule, 

AT-62, "Vehicle Speed When Performing and Releasing Complete Lock-Up"

 .

Item name

Condition 

Display value (Approx.)

TCC SOLENOID

When perform slip lock-up

0.2 - 0.4A

When perform lock-up

0.4 - 0.6A

SAT014K