Nissan Pathfinder (2007 year). Manual - part 209

DTC P1572 ASCD BRAKE SWITCH

EC-539

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2007 Pathfinder

DTC P1572 ASCD BRAKE SWITCH

PFP:25320

Component Description

UBS00KG2

When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to 

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

for the ASCD function.

CONSULT-II Reference Value in Data Monitor Mode

UBS00KG3

Specification data are reference values.

On Board Diagnosis Logic

UBS00KG4

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

NOTE:

●

If DTC P 1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to 

EC-472, "DTC P0605 ECM"

  .

●

This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.

BBIA0560E

MONITOR ITEM

CONDITION

SPECIFICATION

BRAKE SW1
(ASCD brake switch)

●

Ignition switch: ON

Brake pedal: Fully released

ON

Brake pedal: Slightly 
depressed

OFF

BRAKE SW2
(Stop lamp switch)

●

Ignition switch: ON

Brake pedal: Fully released

OFF

Brake pedal: Slightly 
depressed

ON

DTC No.

Trouble Diagnosis 

Name

DTC Detecting Condition

Possible Cause

P1572
1572

ASCD brake switch

A)

When the vehicle speed is above 30km/h 
(19 MPH), ON signals from the stop lamp 
switch and the ASCD brake switch are sent 
to ECM at the same time.

●

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

●

Harness or connectors
(The ASCD brake switch circuit is shorted.)

●

Stop lamp switch

●

ASCD brake switch

●

Incorrect stop lamp switch installation

●

Incorrect ASCD brake switch installation

●

ECM

B)

ASCD brake switch signal is not sent to 
ECM for extremely long time while the vehi-
cle is driving

EC-540

DTC P1572 ASCD BRAKE SWITCH

2007 Pathfinder

DTC Confirmation Procedure

UBS00KG5

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.

●

Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected. 

TESTING CONDITION:
Steps 4 and 5 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.

Press MAIN switch and make sure that CRUISE indicator lights
up.

4.

Drive the vehicle for at least 5 consecutive seconds under the
following condition.

If DTC is detected, go to 

EC-542, "Diagnostic Procedure"

  .

If DTC is not detected, go to the following step.

5.

Drive the vehicle for at least 5 consecutive seconds under the
following condition.

6.

If DTC is detected, go to 

EC-542, "Diagnostic Procedure"

  .

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

VHCL SPEED SE

More than 30 km/h (19 MPH)

Selector lever

Suitable position 

VHCL SPEED SE

More than 30 km/h (19 MPH)

Selector lever

Suitable position 

Driving location

Depress the brake pedal for more than 
five seconds so as not to come off from 
the above-mentioned vehicle speed.

PBIB2386E

DTC P1572 ASCD BRAKE SWITCH

EC-541

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2007 Pathfinder

Wiring Diagram 

UBS00KG6

BBWA2373E

EC-542

DTC P1572 ASCD BRAKE SWITCH

2007 Pathfinder

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

UBS00KG7

1. 

CHECK OVERALL FUNCTION-I

 With CONSULT-II

1.

Turn ignition switch ON.

2.

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

3.

Check “BRAKE SW1” indication under the following conditions.

 Without CONSULT-II

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.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

101

LG

Stop lamp switch

[Ignition switch: OFF]

●

Brake pedal: Fully released

Approximately 0V

[Ignition switch: OFF]

●

Brake pedal: Slightly depressed

BATTERY VOLTAGE
(11 - 14V)

108

LG

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

When brake pedal: Slightly depressed

OFF

When brake pedal: Fully released

ON

SEC011D

CONDITION

VOLTAGE

When brake pedal: Slightly depressed

Approximately 0V

When brake pedal: Fully released

Battery voltage

MBIB0061E

DTC P1572 ASCD BRAKE SWITCH

EC-543

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2007 Pathfinder

2. 

CHECK OVERALL FUNCTION-II

 With CONSULT-II

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

 Without CONSULT-II

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

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 7.

CONDITION

INDICATION

When brake pedal: Fully released

OFF

When brake pedal: Slightly depressed

ON

SEC013D

CONDITION

VOLTAGE

When brake pedal: Fully released

Approximately 0V

When brake pedal: Slightly depressed

Battery voltage

MBIB0060E

EC-544

DTC P1572 ASCD BRAKE SWITCH

2007 Pathfinder

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-II 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 E160

●

10A fuse

●

Harness for open or short between ASCD brake switch and fuse

>> Repair open circuit or short to ground 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 6.

NG

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

6. 

CHECK ASCD BRAKE SWITCH

Refer to 

EC-546, "Component Inspection"

  .

OK or NG

OK

>> GO TO 11.

NG

>> Replace ASCD brake switch.

BBIA0560E

Voltage: Battery voltage

PBIB0857E

Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH

EC-545

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2007 Pathfinder

7. 

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-II or tester.

OK or NG

OK

>> GO TO 9.

NG

>> GO TO 8.

8. 

DETECT MALFUNCTIONING PART

Check the following.

●

Fuse block (J/B) connector E160

●

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.

9. 

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 10.

NG

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

10. 

CHECK STOP LAMP SWITCH

Refer to 

EC-546, "Component Inspection"

  .

OK or NG

OK

>> GO TO 11.

NG

>> Replace stop lamp switch.

BBIA0560E

Voltage: Battery voltage

PBIB1184E

Continuity should exist.

EC-546

DTC P1572 ASCD BRAKE SWITCH

2007 Pathfinder

11. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-145, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

  .

>> INSPECTION END

Component Inspection

UBS00KG8

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.

If NG, adjust ASCD brake switch installation, refer to 

BR-6,

"BRAKE PEDAL"

  , 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.

If NG, adjust stop lamp switch installation, refer to 

BR-6,

"BRAKE PEDAL"

  , and perform step 3 again.

Condition

Continuity

When brake pedal: Fully released.

Should exist.

When brake pedal: Slightly depressed.

Should not exist.

SEC023D

Condition

Continuity

When brake pedal: Fully released.

Should not exist.

When brake pedal: Slightly depressed.

Should exist.

PBIB1185E