Nissan Frontier D22. Manual - part 75

DTC P0725 ENGINE SPEED SIGNAL

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3. 

CHECK DTC

Perform Diagnostic Trouble Code (DTC) confirmation procedure. Refer to 

AT-266, "DIAGNOSTIC TROUBLE

CODE (DTC) CONFIRMATION PROCEDURE"

 .

OK or NG

OK

>> INSPECTION END.

NG

>> 1. Perform TCM input/output signal inspection.

2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.

AT-270

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DTC P0731 IMPROPER SHIFTING TO 1ST GEAR POSITION

DTC P0731 IMPROPER SHIFTING TO 1ST GEAR POSITION

PFP:31940

Description

ECS007MJ

●

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

●

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

●

This malfunction is detected when the A/T does not shift into first gear position 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, etc.

TCM TERMINALS AND REFERENCE VALUE

Remarks: Specification data are reference values.

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 higher than the position (1st) supposed by TCM, the slip ratio will be more than
normal. In case the ratio exceeds the specified value, TCM judges this diagnosis malfunction.
This malfunction will be caused when either shift solenoid valve A is stuck open or shift solenoid valve B is
stuck open.

*: P0731 is detected.

Gear position

1

2

3

4

Shift solenoid valve A

ON (Closed)

OFF (Open)

OFF (Open)

ON (Closed)

Shift solenoid valve B

ON (Closed)

ON (Closed)

OFF (Open)

OFF (Open)

Terminal 

No.

Wire color

Item

Condition

Judgement stan-

dard (Approx.)

11

L/W

Shift solenoid 
valve A

When shift solenoid valve A oper-
ates.
(When driving in D

1

  or D

4

 )

Battery voltage

When shift solenoid valve A does not 
operate.
(When driving in D

2

  or D

3

 )

0V

12

L/Y

Shift solenoid 
valve B

When shift solenoid valve B oper-
ates.
(When driving in D

1

  or D

2

 )

Battery voltage

When shift solenoid valve B does not 
operate.
(When driving in D

3

  or D

4

 )

0V

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 A stuck open

2*

2

3

3

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

4*

3

3

4

Diagnostic trouble code

Malfunction is detected when ...

Check item (Possible cause)

: A/T 1ST GR FNCTN

A/T cannot be shifted to the 1st gear posi-
tion even if electrical circuit is good.

●

Shift solenoid valve A

●

Shift solenoid valve B

●

Each clutch

●

Hydraulic control circuit

: P0731

DTC P0731 IMPROPER SHIFTING TO 1ST GEAR POSITION

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DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PROCEDURE

CAUTION:

●

Always drive vehicle at a safe speed.

●

Be careful not to rev engine into the red zone on the
tachometer.

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.
TESTING CONDITIONS:
Always drive vehicle on a level road to improve the accuracy of 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  “1ST GR FNCTN P0731” of “DTC WORK SUPPORT”
mode for “A/T” with CONSULT-II and touch “START”.

4.

Accelerate vehicle to 17 to 23 km/h (11 to 14 MPH) under the
following condition and release the accelerator pedal com-
pletely.
THROTTLE POSI: Less than 1/8 (at all times during step 4)
Selector lever: D position (O/D ON)

–

Check that “GEAR” shows 2 after releasing pedal.

5.

Depress accelerator pedal to WOT (more than 7/8 of “THROT-
TLE POSI”) quickly from a speed of 17 to 23 km/h (11 to 14
MPH) until “TESTING” changes to “STOP VEHICLE” or “COM-
PLETED”. (It will take approximately 3 seconds)
If the check result NG appears on CONSULT-II screen, go to 

AT-

274, "Diagnostic Procedure"

 .

If “STOP VEHICLE” appears on CONSULT-II screen, go to the
following step.

–

Check that “GEAR” shows 1 when depressing accelerator
pedal to WOT.

–

If “TESTING” does not appear on CONSULT-II for a long time, select “SELF-DIAG RESULTS” for
“ENGINE”. In case a 1st trip DTC other than P0731 is shown, refer to applicable “TROUBLE DIAG-
NOSIS FOR DTC”.

6.

Stop vehicle.

7.

Follow the instruction displayed. (Check for normal shifting referring to the table below.)

8.

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

AT-274, "Diagnostic Procedure"

 .

Refer to 

AT-496, "Shift Schedule"

 .

Vehicle condition

Gear on actual transmission shift pattern when 

screen is changed to 1 

→ 2 → 3 → 4

No malfunction exists

1 

→ 2 → 3 → 4

Malfunction for P0731 exists.

2 

→ 2 → 3 → 3

4 

→ 3 → 3 → 4

SAT014K

SAT971J

SAT021J

AT-272

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DTC P0731 IMPROPER SHIFTING TO 1ST GEAR POSITION

 With GST

●

Follow the procedure “With CONSULT-II”.