Infiniti FX35 / FX45. Manual - part 429

DTC P1572 ASCD BRAKE SWITCH

EC-477

< SERVICE INFORMATION >

[VQ35DE]

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Diagnosis Procedure

INFOID:0000000001326342

1.

CHECK OVERALL FUNCTION-I

 With CONSULT-III

1.

Turn ignition switch ON.

2.

Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-III.

3.

Check “BRAKE SW1” indication under the following conditions.

 Without CONSULT-III

1.

Turn ignition switch ON.

2.

Check voltage between ECM terminal 108 and ground under the
following conditions.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 3.

2.

CHECK OVERALL FUNCTION-II

 With CONSULT-III

Check “BRAKE SW2” indication in “DATA MONITOR” mode. 

 Without CONSULT-III

Check voltage between ECM terminal 101 and ground under the following conditions.

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

101

P/L

Stop lamp switch

[Ignition switch: OFF]
• Brake pedal: Fully released

Approximately 0V

[Ignition switch: OFF]
• Brake pedal: Slightly depressed

BATTERY VOLTAGE
(11 - 14V)

108

SB

ASCD brake switch

[Ignition switch: ON]
• Brake pedal: Slightly depressed

Approximately 0V

[Ignition switch: ON]
• Brake pedal: Fully released

BATTERY VOLTAGE
(11 - 14V)

CONDITION

INDICATION

Brake pedal: Slightly depressed

OFF

Brake pedal: Fully released

ON

CONDITION

VOLTAGE

Brake pedal: Slightly depressed

Approximately 0V

Brake pedal: Fully released

Battery voltage

MBIB0061E

CONDITION

INDICATION

Brake pedal: Fully released

OFF

Brake pedal: Slightly depressed

ON

EC-478

< SERVICE INFORMATION >

[VQ35DE]

DTC P1572 ASCD BRAKE SWITCH

OK or NG

OK

>> GO TO 13.

NG

>> GO TO 8.

3.

CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ASCD brake switch harness connector.

3.

Turn ignition switch ON.

4.

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

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

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

5.

CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

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

4.

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

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

CONDITION

VOLTAGE

Brake pedal: Fully released

Approximately 0V

Brake pedal: Slightly depressed

Battery voltage

MBIB0060E

PBIB1605E

Voltage: Battery voltage

PBIB0857E

Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH

EC-479

< SERVICE INFORMATION >

[VQ35DE]

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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-480, "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.

PBIB1605E

Voltage: Battery voltage

PBIB1184E

Continuity should exist.

EC-480

< SERVICE INFORMATION >

[VQ35DE]

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-480, "Component Inspection"

 

OK or NG

OK

>> GO TO 13.

NG

>> Replace stop lamp switch.

13.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326343

ASCD BRAKE SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect ASCD brake switch harness connector.

3.

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

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

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

SEC023D

Condition

Continuity

Brake pedal: Fully released

Should not exist

Brake pedal: Slightly depressed

Should exist

PBIB1185E