Infiniti F50. Manual - part 489

DTC P1706 PNP SWITCH

EC-597

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10. 

CHECK FUSE BLOCK (J/B) NO. 1

Refer to 

PG-66, "FUSE BLOCK - JUNCTION BOX (J/B) NO.1"

 .

OK or NG

OK

>> GO TO 11.

NG

>> Replace fuse block (J/B) No. 1.

11. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

EC-598

DTC P1720 VEHICLE SPEED SENSOR (A/T OUTPUT)

DTC P1720 VEHICLE SPEED SENSOR (A/T OUTPUT)

PFP:31036

Description

EBS00MME

NOTE:
If DTC P1720 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to

EC-141, "DTC U1000, U1001 CAN COMMUNICATION LINE"

 .

ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from VDC/TCS/ABS
control unit, and the other is from TCM (Transmission control module). ECM uses these two signals for engine
control.

CONSULT-II Reference Value in Data Monitor Mode

EBS00MMF

Specification data are reference values.

On Board Diagnosis Logic

EBS00MMG

DTC Confirmation Procedure

EBS00MMH

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.

 WITH CONSULT-II

1.

Turn ignition switch “ON”.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Start engine.

4.

Drive vehicle at a speed of 20 km/h (12 MPH) or more for at least 5 seconds without brake pedal depress-
ing.

5.

If 1st trip DTC is detected, go to 

EC-599, "Diagnostic Procedure"

 .

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

MONITOR ITEM

CONDITION

SPECIFICATION

VEH SPEED SE

●

Turn drive wheels and compare the CONSULT-II value with speedometer 
indication.

Almost the same speed as the 
speedometer indication  

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1720
1720

Vehicle speed sensor
 (A/T output)

ECM detects a difference between two 
vehicle speed sensor signals is out of the 
specified range.

●

Harness or connectors
(The CAN communication line is open or 
shorted)

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Harness or connectors
(Revolution sensor circuit is open or shorted)

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Harness or connectors
(Wheel sensor circuit is open or shorted.)

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TCM

●

VDC/TCS/ABS control unit

●

Combination meter

DTC P1720 VEHICLE SPEED SENSOR (A/T OUTPUT)

EC-599

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Diagnostic Procedure

EBS00MMI

1. 

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

AT-42, "TROUBLE DIAGNOSIS"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Perform trouble shooting relevant to DTC indicated.

2. 

CHECK DTC WITH VDC/TCS/ABS CONTROL UNIT

Check DTC with VDC/TCS/ABS control unit. Refer to 

BRC-12, "TROUBLE DIAGNOSIS"

 .

OK or NG

OK

>> GO TO 3.

NG

>> Perform trouble shooting relevant to DTC indicated.

3. 

CHECK COMBINATION METER

Check combination meter function. Refer to 

DI-7, "COMBINATION METERS"

 .

>> INSPECTION END

EC-600

DTC P1780 SHIFT CHANGE SIGNAL

DTC P1780 SHIFT CHANGE SIGNAL

PFP:31036

Description

EBS00MMJ

NOTE:
If DTC P1780 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to

EC-141, "DTC U1000, U1001 CAN COMMUNICATION LINE"

 .

ECM receives current gear position signal, next gear position signal, shift change signal, shift pattern signal
through CAN communication line from TCM (Transmission control module). ECM uses these four signals for
engine control.

On Board Diagnosis Logic

EBS00MMK

DTC Confirmation Procedure

EBS00MML

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.

 WITH CONSULT-II

1.

Perform DTC confirmation procedure for DTC P1754, refer to 

AT-175, "DTC Confirmation Procedure"

 .

2.

If 1st trip DTC is detected, go to 

EC-600, "Diagnostic Procedure"

 .

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

Diagnostic Procedure

EBS00MMM

1. 

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

AT-42, "TROUBLE DIAGNOSIS"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Perform trouble shooting relevant to DTC indicated.

2. 

CHECK TCM FUNCTION

Refer to 

AT-42, "TROUBLE DIAGNOSIS"

 .

OK or NG

OK

>> GO TO 3.

NG

>> Replace TCM. Refer to 

AT-7, "PRECAUTIONS"

 .

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1780
1780

Shift change signal

A)

The next gear position signal and the current gear 
position signal are not in the normal pattern com-
pared with the shift pattern signal,

●

Harness or connectors
(CAN communication line circuit 
is open or shorted)

●

TCM

●

A/T unit assembly

B)

The next gear position signal and the current gear 
position signal are different even through the shift 
change signal is “OFF”.