Infiniti FX35 / FX45. Manual - part 578

DTC P1572 ASCD BRAKE SWITCH

EC-1073

< SERVICE INFORMATION >

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6.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E211, M41
• 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.

7.

CHECK ASCD BRAKE SWITCH

Refer to 

EC-1074, "Component Inspection"

 

OK or NG

OK

>> GO TO 13.

NG

>> Replace ASCD brake switch.

8.

CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect stop lamp switch harness connector.

3.

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

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 9.

9.

DETECT MALFUNCTIONING PART

Check the following.
• Fuse block (J/B) connector E201
• 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

1.

Disconnect ECM harness connector.

2.

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

3.

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

OK or NG

OK

>> GO TO 12.

PBIB2558E

Voltage: Battery voltage

PBIB1184E

Continuity should exist.

EC-1074

< SERVICE INFORMATION >

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DTC P1572 ASCD BRAKE SWITCH

NG

>> GO TO 11.

11.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E211, M41
• 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-1074, "Component Inspection"

 

OK or NG

OK

>> GO TO 13.

NG

>> Replace stop lamp switch.

13.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-717

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326948

ASCD BRAKE SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect ASCD brake switch harness connector.

3.

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

4.

If NG, adjust ASCD brake switch installation, refer to 

BR-5

, and

perform step 3 again.

STOP LAMP SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect stop lamp switch harness connector.

3.

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

4.

If NG, adjust stop lamp switch installation, refer to 

BR-5

, 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

PBIB1535E

DTC P1574 ICC VEHICLE SPEED SENSOR

EC-1075

< SERVICE INFORMATION >

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DTC P1574 ICC VEHICLE SPEED SENSOR

Component Description

INFOID:0000000001326949

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-7

 for ICC functions.

On Board Diagnosis Logic

INFOID:0000000001326950

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-724

.

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

to 

EC-726

.

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

to 

EC-992

.

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

Refer to 

EC-1007

.

DTC Confirmation Procedure

INFOID:0000000001326951

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.

1.

Start engine (VDC switch OFF).

2.

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

3.

Check DTC.

4.

If DTC is detected, go to 

EC-1075, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000001326952

1.

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

AT-38

.

OK or NG

OK

>> GO TO 2.

NG

>> Perform trouble shooting relevant to DTC indicated.

2.

CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”

Refer to 

BRC-13

.

OK or NG

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

EC-1076

< SERVICE INFORMATION >

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DTC P1574 ICC VEHICLE SPEED SENSOR

OK

>> GO TO 3.

NG

>> Repair or replace.

3.

CHECK DTC WITH “UNIFIED METER AND A/C AMP.”

Check combination meter function.
Refer to 

DI-26

.

>> INSPECTION END