Infiniti FX35, FX50 (S51). Manual - part 1863

P0725 ENGINE SPEED

TM-259

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B (VK50VE)]

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P0725 ENGINE SPEED

Description

INFOID:0000000005250239

The engine speed signal is transmitted from the ECM to the TCM with CAN communication line.

DTC Logic

INFOID:0000000005250240

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

 With CONSULT-III

1.

Start the engine.

2.

Select “SLCT LVR POSI” and “VHCL/S SE-A/T” in “Data Monitor” in “TRANSMISSION”.

3.

Drive vehicle and maintain the following conditions for 5 seconds or more.

4.

Perform “Self Diagnostic Results” in “TRANSMISSION”.

Is “P0725” detected?

YES

>> Go to 

TM-259, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005250241

1.

CHECK DTC OF ECM

 With CONSULT-III

1.

Turn ignition switch ON.

2.

Perform “Self Diagnostic Results” in “ENGINE”.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Check DTC detected item. Refer to 

EC-718, "CONSULT-III Function"

.

2.

CHECK DTC OF TCM

 With CONSULT-III

Perform “Self Diagnostic Results” in “TRANSMISSION”.
Is any DTC other than “P0725” detected?

YES

>> GO TO 3.

NO

>> Check DTC detected item. Refer to 

TM-243, "CONSULT-III Function (TRANSMISSION)"

.

DTC

Trouble diagnosis name

DTC is detected if...

Possible cause

P0725

Engine Speed Input Circuit

• TCM does not receive the 

CAN communication signal 
from the ECM.

• The engine speed is more 

less 150 rpm even if the vehi-
cle speed is more than 10 km/
h (7 MPH).

Harness or connectors
(ECM to TCM circuit is open or 
shorted.)

SLCT LVR POSI

: D

VHCL/S SE-A/T

: More than 10km/h (7 MPH)

TM-260

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B (VK50VE)]

P0725 ENGINE SPEED

3.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace A/T assembly. Refer to 

TM-362, "Exploded View"

.

NO

>> Repair or replace damaged parts.

P0729 6GR INCORRECT RATIO

TM-261

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B (VK50VE)]

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P0729 6GR INCORRECT RATIO

Description

INFOID:0000000005250242

This malfunction is detected when the A/T does not shift into 6GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or shorted) but by mechanical malfunction such as control
valve sticking, improper solenoid valve operation, etc.

DTC Logic

INFOID:0000000005250243

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

• “

TM-262, "Diagnosis Procedure"

” must be performed before starting “DTC CONFIRMATION PROCE-

DURE”.

• Never perform “DTC CONFIRMATION PROCEDURE” before completing the repair, which may cause

secondary malfunction.

• Always drive vehicle at a safe speed.

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK ATF TEMPERATURE

 With CONSULT-III

1.

Start the engine.

2.

Select “ATF TEMP 1” in “Data Monitor” in “TRANSMISSION”.

3.

Check ATF temperature is in the following range.

 With GST

1.

Start the engine.

2.

Drive vehicle for approximately 5 minutes in urban areas.

Is ATF temperature within specified range?

YES

>> GO TO 3.

NO

>> Drive vehicle to warm ATF or stop engine to cool ATF.

3.

CHECK SYMPTOM (PART 1)

 With CONSULT-III

1.

Select “6TH GR FNCTN P0729” in “DTC & SRT confirmation” in “TRANSMISSION”.

2.

Drive vehicle with manual mode and maintain the following conditions.

DTC

Trouble diagnosis name

DTC is detected if...

Possible cause

P0729

Gear 6 Incorrect Ratio

The gear ratio is:
• 0.916 or more
• 0.812 or less

• Input clutch solenoid valve
• Direct clutch solenoid valve
• High and low reverse clutch 

solenoid valve

• Front brake solenoid valve
• Low brake solenoid valve
• 2346 brake solenoid valve
• Anti-interlock solenoid valve
• Each clutch and brake
• Output speed sensor
• Input speed sensor 1, 2
• Hydraulic control circuit

ATF TEMP 1

: 20

°

C (68

°

F) – 140

°

C (284

°

F)

TM-262

< DTC/CIRCUIT DIAGNOSIS >

[7AT: RE7R01B (VK50VE)]

P0729 6GR INCORRECT RATIO

3.

Keep the current driving status for 2 seconds or more if CONSULT-III screen changes from “OUT OF
CONDITION” to “TESTING”.

CAUTION:

When “TESTING” is not detected on CONSULT-III for a long time, check “Self Diagnostic Results”
in “TRANSMISSION”. When a DTC other than “P0729” is detected, check the DTC. Refer to 

TM-

332, "DTC Index"

.

 With GST

1.

Drive vehicle and maintain the following conditions for 2 seconds or more.

2.

Check DTC.

Is  “OUT OF CONDITION”,  “STOP VEHICLE” or “COMPLETED RESULT NG” displayed? / Is “P0729”
detected?

YES-1 >> “OUT OF CONDITION”: Perform “Step 3” again.
YES-2 >> “STOP VEHICLE”: GO TO 4.
YES-3 >> “COMPLETED RESULT NG”: Go to 

TM-262, "Diagnosis Procedure"

.

YES-4 >> “P0729” is detected: Go to 

TM-262, "Diagnosis Procedure"

.

NO

>> GO TO 4.

4.

CHECK SYMPTOM (PART 2)

1.

Stop vehicle.

2.

Drive vehicle in “D” position allowing it to shift from 1GR to 7GR and check shift timing and shift shock.

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005250244

1.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace A/T assembly. Refer to 

TM-362, "Exploded View"

.

NO

>> Repair or replace damaged parts.

GEAR

: 6th

ACCELE POSI

: 0.7/8 or more

VEHICLE SPEED

: 10 km/h (7 MPH) or more

Selector lever

: “M” position

Gear position

: 6th

Accelerator pedal opening

: 0.7/8 or more

Vehicle speed

: 10 km/h (7 MPH) or more