Infiniti G35 (V35). Manual - part 421

DTC P1574 ASCD VEHICLE SPEED SENSOR

EC-565

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EC

DTC P1574 ASCD VEHICLE SPEED SENSOR

PFP:31036

Component Description

NBS00104

The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combina-
tion meter and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD
control. Refer to 

EC-29, "AUTOMATIC SPEED CONTROL DEVICE (ASCD)"

  for ASCD functions.

On Board Diagnosis Logic

NBS00105

●

This self-diagnosis has the one trip detection logic.

●

The MIL will not light up for this self-diagnosis.

NOTE:

●

If DTC P1574 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to 

EC-161, "DTC U1000, U1001 CAN COMMUNICATION LINE"

 .

●

If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to 

EC-480, "DTC P0500 VSS"

●

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to 

EC-496, "DTC P0605 ECM"

DTC Confirmation Procedure

NBS00106

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.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.

 WITH CONSULT-II

1.

Start engine (VDC switch OFF).

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Drive the vehicle at more than 40 km/h (25 MPH).

4.

If DTC is detected, go to 

EC-566, "Diagnostic Procedure"

 .

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

DTC No.

Trouble Diagnosis 

Name

DTC Detecting Condition

Possible Cause

P1574
1574

ASCD vehicle speed 
sensor

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

●

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

●

Combination meter

●

VDC/TCS/ABS control unit

●

Wheel sensor

●

TCM (A/T models)

●

ECM

PBIB2673E

EC-566

DTC P1574 ASCD VEHICLE SPEED SENSOR

Diagnostic Procedure

NBS00107

1. 

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

AT-37, "OBD-II Diagnostic Trouble Code (DTC)"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Perform trouble shooting relevant to DTC indicated.

2. 

CHECK DTC WITH VDC/TCS/ABS CONTROL UNIT

Refer to 

BRC-10, "TROUBLE DIAGNOSIS"

 .

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace.

3. 

CHECK COMBINATION METER

Check combination meter function.
Refer to 

DI-4, "COMBINATION METERS"

 .

>> INSPECTION END

DTC P1715 INPUT SPEED SENSOR (TURBINE REVOLUTION SENSOR)

EC-567

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DTC P1715 INPUT SPEED SENSOR (TURBINE REVOLUTION SENSOR)

PFP:31935

Description

NBS002W5

ECM receives turbine revolution sensor signal from TCM through CAN communication line. ECM uses this
signal for engine control.

CONSULT-II Reference Value in Data Monitor Mode

NBS002W6

Specification data are reference values.

On Board Diagnosis Logic

NBS002W7

NOTE:

●

If DTC P1715 is displayed with DTC U1000, U1001 first perform the trouble diagnosis for DTC
U1000, U1001. Refer to 

EC-161, "DTC U1000, U1001 CAN COMMUNICATION LINE"

 .

●

If DTC P1715 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010.
Refer to 

EC-164, "DTC U1010 CAN COMMUNICATION"

 .

●

If DTC P1715 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to 

EC-496, "DTC P0605 ECM"

 .

●

If DTC P1715 is displayed with DTC P0340 or P0345 first perform the trouble diagnosis for DTC
P0340 or P0345. Refer to 

EC-382, "DTC P0340, P0345 CMP SENSOR (PHASE)"

 .

The MIL will not light up for this self-diagnosis.

Diagnostic Procedure

NBS002W8

1. 

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

AT-37, "ON BOARD DIAGNOSTIC (OBD) SYSTEM"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Perform trouble shooting relevant to DTC indicated.

2. 

REPLACE TCM

Replace TCM. Refer to 

AT-41, "TROUBLE DIAGNOSIS"

 .

>> INSPECTION END

MONITOR ITEM

CONDITION

SPECIFICATION

I/P PULLY SPD

●

Vehicle speed: More than 20 km/h (12MPH)

Almost the same speed as the 
tachometer indication

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1715
1715

Input speed sensor
(Turbine revolution sen-
sor)
(TCM output)

Turbine revolution sensor signal is differ-
ent from the theoretical value calculated 
by ECM from revolution sensor signal 
and engine rpm signal.

●

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

●

Harness or connectors
(Turbine revolution sensor circuit is open or 
shorted)

●

TCM

EC-568

DTC P1805 BRAKE SWITCH

DTC P1805 BRAKE SWITCH

PFP:25320

Description

NBS0010F

Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.

CONSULT-II Reference Value in Data Monitor Mode

NBS0010G

Specification data are reference values.

On Board Diagnosis Logic

NBS0010H

The MIL will not light up for this self-diagnosis.

FAIL-SAFE MODE

When the malfunction is detected, the ECM enters fail-safe mode.

DTC Confirmation Procedure

NBS0010I

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Fully depress the brake pedal for at least 5 seconds.

3.

Erase the DTC with CONSULT-II.

4.

Select “DATA MONITOR” mode with CONSULT-II.

5.

If 1st trip DTC is detected, go to 

EC-570, "Diagnostic Procedure"

.

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

MONITOR ITEM

CONDITION

SPECIFICATION

BRAKE SW

●

Ignition switch: ON

Brake pedal: Fully released

OFF

Brake pedal: Slightly depressed

ON

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1805
1805

Brake switch

A brake switch signal is not sent to ECM for 
extremely long time while the vehicle is driving.

●

Harness or connectors
(The stop lamp switch circuit is open or 
shorted.)

●

Stop lamp switch

Engine operating condition in fail-safe mode

ECM controls the electric throttle control actuator by regulating the throttle opening to a small range.
Therefore, acceleration will be poor.

Vehicle condition

Driving condition

When engine is idling

Normal

When accelerating

Poor acceleration

SEF058Y