Nissan Frontier D22. Manual - part 82

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE

AT-297

[RE4R01A]

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Component Inspection

ECS007N2

TORQUE CONVERTER CLUTCH SOLENOID VALVE

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For removal, refer to 

AT-402, "REMOVAL"

 .

Resistance Check

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Check resistance between torque converter clutch solenoid valve terminal 7 and ground.

Operation Check

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Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminal 7 and ground.

SAT160J

Solenoid valve

Terminal No.

Resistance (Approx.)

Torque converter clutch sole-
noid valve

7

Ground

10 - 20 

Ω

SAT161J

AT-298

[RE4R01A]

DTC P0744 IMPROPER LOCK-UP OPERATION

DTC P0744 IMPROPER LOCK-UP OPERATION

PFP:31940

Description

ECS007N3

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This is an OBD-II self-diagnostic item and not available in TCM self-diagnosis.

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This malfunction will not be detected while the O/D OFF indicator lamp is indicating another self-diagnosis
malfunction.

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This malfunction is detected when the A/T does not shift into fourth gear position, or the torque converter
clutch does not lock up as instructed by the TCM. This is not caused by electrical malfunction (circuits
open or shorted), but by mechanical malfunction such as control valve sticking, improper solenoid valve
operation, malfunctioning oil pump or torque converter clutch, etc.

CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE

Remarks: Specification data are reference values.

TCM TERMINALS AND REFERENCE VALUE

Remarks: Specification data are reference values.

Monitor item

Condition

Specification (Approx.)

Torque converter clutch sole-
noid valve duty

Lock-up OFF

↓

Lock-up ON

4%

↓

94%

Terminal 

No.

Wire color

Item

Condition

Judgement stan-

dard (Approx.)

1

GY/R

Line pressure 
solenoid valve

When releasing accelerator pedal 
after warming up engine.

1.5 - 2.5V

When depressing accelerator pedal 
fully after warming up engine.

0V

2

BR/Y

Line pressure 
solenoid valve
(with dropping 
resistor)

When releasing accelerator pedal 
after warming up engine.

4 - 14V

When depressing accelerator pedal 
fully after warming up engine.

0V

3

G/OR

Torque converter 
clutch solenoid 
valve

When A/T performs lock-up.

8 - 15V

When A/T does not perform lock- up.

0V

DTC P0744 IMPROPER LOCK-UP OPERATION

AT-299

[RE4R01A]

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ON BOARD DIAGNOSIS LOGIC

This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by TCM as
follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th) supposed by TCM, the slip ratio will be much
less than normal. In case the ratio does not reach the specified value, TCM judges this diagnosis malfunction.
This malfunction will be caused when shift solenoid valve B is stuck closed.

*: P0744 is detected.

DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
If “DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DURE” has been previously conducted, always turn ignition
switch OFF and wait at least 5 seconds before conducting the
next test.
After the repair, perform the following procedure to confirm the mal-
function is eliminated.

 With CONSULT-II

1.

Start engine and select “DATA MONITOR” mode for “A/T” with
CONSULT-II.

2.

Make sure that output voltage of A/T fluid temperature sensor is
within the range below.
FLUID TEMP SEN: 0.4 - 1.5V
If out of range, drive the vehicle to decrease the voltage (warm
up the fluid), or stop engine to increase the voltage (cool down
the fluid).

3.

Select  “TCC S/V FNCTN P0744” of “DTC WORK SUPPORT”
mode for “A/T” with CONSULT-II and touch “START”.

Gear position supposed by TCM

1

2

3

4

In case of gear position with no malfunctions

1

2

3

4

In case of gear position with shift solenoid valve B stuck closed

1

2

2

1*

Diagnostic trouble code

Malfunction is detected when ...

Check item (Possible cause)

: A/T TCC S/V FNCTN

A/T cannot perform lock-up even if electri-
cal circuit is good.

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Line pressure solenoid valve

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Torque converter clutch solenoid valve

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Each clutch

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Hydraulic control circuit

: P0744

SAT014K

SAT971J

AT-300

[RE4R01A]

DTC P0744 IMPROPER LOCK-UP OPERATION

4.

Accelerate vehicle to more than 70 km/h (43 MPH) and maintain
the following condition continuously until “TESTING” has turned
to  “COMPLETED”. (It will take approximately 30 seconds after
“TESTING” shows.)
THROTTLE POSI: 1/8 - 2/8 (at all times during step 4)
Selector lever: D position (O/D ON)
TCC S/V DUTY: More than 94%
VHCL/S SE·A/T: Constant speed of more than 70 km/h (43
MPH)

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Check that “GEAR” shows 4.

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For shift schedule, refer to 

AT-496, "Shift Schedule"

 .

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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”.

5.

Make sure that “OK” is displayed. (If “NG” is displayed, refer to 

AT-302, "Diagnostic Procedure"

 .)

Refer to 

AT-496, "Shift Schedule"

 .

 With GST

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Follow the procedure “With CONSULT-II”.

SAT021J