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Infiniti M35/M45 Y50. Manual - part 527

DTC P1572 ASCD BRAKE SWITCH

EC-581

[VQ35DE]

CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

Turn ignition switch OFF.

Disconnect ASCD brake switch (2) harness connector.

–

Stop lamp switch (1)

Turn ignition switch ON.

Check voltage between ASCD brake switch terminal 1 and
ground with CONSULT-II or tester.

OK or NG

>> GO TO 5.

>> GO TO 4.

DETECT MALFUNCTIONING PART

Check the following.

●

Fuse block (J/B) connector E102

●

10A fuse

●

Harness for open or short between ASCD brake switch and fuse

>> Repair open circuit or short to ground or short to power in harness or connectors.

CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.

Disconnect ECM harness connector.

Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to Wiring Diagram.

Also check harness for short to ground and short to power.

OK or NG

>> GO TO 7.

>> GO TO 6.

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E108, M15

●

Harness for open or short between ECM and ASCD brake switch

>> Repair open circuit or short to ground or short to power in harness or connectors.

PBIB2705E

Voltage: Battery voltage

PBIB0857E

Continuity should exist.

EC-582

[VQ35DE]

DTC P1572 ASCD BRAKE SWITCH

CHECK ASCD BRAKE SWITCH

Refer to

EC-583, "Component Inspection"

OK or NG

>> GO TO 13.

>> Replace ASCD brake switch.

CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT

Turn ignition switch OFF.

Disconnect stop lamp switch (1) harness connector.

–

ASCD brake switch (2)

Check voltage between stop lamp switch terminal 1 and ground
with CONSULT -II or tester.

OK or NG

>> GO TO 10.

>> GO TO 9.

DETECT MALFUNCTIONING PART

Check the following.

●

Fuse block (J/B) connector E101

●

10A fuse

●

Harness for open or short between stop lamp switch and battery

>> Repair open circuit or short to ground or short to power in harness or connectors.

10.

CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

Disconnect ECM harness connector.

Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2.
Refer to Wiring Diagram.

Also check harness for short to ground and short to power.

OK or NG

>> GO TO 12.

>> GO TO 11.

PBIB2705E

Voltage: Battery voltage

PBIA9488J

Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH

EC-583

[VQ35DE]

11.

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E108, M15

●

Harness for open or short between ECM and stop lamp switch

>> Repair open circuit or short to ground or short to power in harness or connectors.

12.

CHECK STOP LAMP SWITCH

Refer to

EC-583, "Component Inspection"

OK or NG

>> GO TO 13.

>> Replace stop lamp switch.

13.

CHECK INTERMITTENT INCIDENT

Refer to

EC-153, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

>> INSPECTION END

Component Inspection

NBS0055D

ASCD BRAKE SWITCH

Turn ignition switch OFF.

Disconnect ASCD brake switch harness connector.

Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.

If NG, adjust ASCD brake switch installation, refer to

BR-6,

"BRAKE PEDAL"

, and perform step 3 again.

STOP LAMP SWITCH

Turn ignition switch OFF.

Disconnect stop lamp switch harness connector.

Check harness continuity between stop lamp switch terminals 1
and 2 under the following conditions.

If NG, adjust stop lamp switch installation, refer to

BR-6,

"BRAKE PEDAL"

, and perform step 3 again.

Condition

Continuity

Brake pedal: Fully released.

Should exist.

Brake pedal: Slightly depressed.

Should not exist.

PBIB1536E

Condition

Continuity

Brake pedal: Fully released.

Should not exist.

Brake pedal: Slightly depressed.

Should exist.

PBIA9489J

EC-584

[VQ35DE]

DTC P1574 ICC VEHICLE SPEED SENSOR

PFP:31036

Component Description

NBS0055E

The ECM receives two vehicle speed signals via CAN communication line. One is sent from “unified meter and
A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals for ICC
control. Refer to

ACS-6, "DESCRIPTION"

for ICC functions.

On Board Diagnosis Logic

NBS0055F

This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.

NOTE:

●

If DTC P1574 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 P1574 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010.
Refer to

EC-164, "DTC U1010 CAN COMMUNICATION"

●

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

EC-468, "DTC P0500 VSS"

●

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

EC-483, "DTC P0605 ECM"

DTC Confirmation Procedure

NBS0055G

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

Start engine (VDC switch OFF).

Select “DATA MONITOR” mode with CONSULT-II.

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

If DTC is detected, go to

EC-585, "Diagnostic Procedure"

WITH GST

Follow the procedure “WITH CONSULT-II” above.

DTC No.

Trouble diagnosis

name

DTC detecting condition

Possible cause

P1574
1574

ICC 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.)

●

Unified meter and A/C amp.

●

ABS actuator and electric unit (control unit)

●

Wheel sensor

●

TCM

●

ECM

PBIB2673E

Content .. 525 526 527 528 ..