Nissan X-Trail 32. Manual - part 804

P1568 SIGNAL INVALID

EC-345

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

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A

EC

N

P

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1.

Replace chassis control module. Refer to 

DAS-278, "Removal and Installation"

.

2.

Perform DTC Confirmation Procedure again.

Is DTC P1568 detected again?

YES

>> Replace ECM. Refer to 

EC-430, "Removal and Installation"

.

NO

>> INSPECTION END

EC-346

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

P1572 ASCD BRAKE SWITCH

P1572 ASCD BRAKE SWITCH

DTC Description

INFOID:0000000010775244

DTC DETECTION LOGIC

NOTE:
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.

POSSIBLE CAUSE

• Harness or connectors
- Stop lamp switch circuit is shorted.
- Brake pedal position switch circuit is shorted.
• Stop lamp switch
• Brake pedal position switch
• Incorrect stop lamp switch installation
• Incorrect brake pedal position switch installation
• ECM

FAIL-SAFE

Not applicable

DTC CONFIRMATION PROCEDURE

1.

CHECK DTC PRIORITY

If DTC P1572 is displayed with DTC P0605, perform the trouble diagnosis for DTC P0605.

Is applicable DTC detected?

YES

>> Perform diagnosis of applicable. Refer to 

EC-314, "DTC Description"

.

NO

>> GO TO 2.

2.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

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

Will CONSULT be used?

YES

>> GO TO 3.

NO

>> GO TO 5.

3.

PERFORM DTC CONFIRMATION PROCEDURE-1

With CONSULT

1.

Start engine.

2.

Select “DATA MONITOR” mode of “ENGINE” using CONSULT.

3.

Press MAIN switch and make sure that CRUISE indicator is displayed in combination meter.

4.

Drive the vehicle for at least 5 consecutive seconds as per the following conditions.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

P1572

ASCD BRAKE SW
(ASCD brake switch)

A

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

B

Brake pedal position switch signal is not sent to ECM for extremely long 
time while the vehicle is driving.

P1572 ASCD BRAKE SWITCH

EC-347

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

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A

EC

N

P

O

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
This procedure 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.

5.

Check DTC.

Is DTC detected?

YES

>> Proceed to 

EC-348, "Diagnosis Procedure"

.

NO

>> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE-2

With CONSULT

1.

Drive the vehicle and maintain the following condition for at least 5 seconds.

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
This procedure 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.

2.

Check DTC.

Is DTC detected?

YES

>> Proceed to 

EC-348, "Diagnosis Procedure"

.

NO-1

>> To check malfunction symptom before repair: Refer to 

GI-44, "Intermittent Incident"

.

NO-2

>> Confirmation after repair: INSPECTION END

5.

PERFORM COMPONENT FUNCTION CHECK

Without CONSULT

NOTE:
Use component function check to check the overall function of Brake pedal position switch and Stop lamp
switch circuit. During this check, a DTC might not be confirmed.   
1.

Turn ignition switch ON.

2.

Check the voltage between ECM harness connector terminals as per the following conditions.

Is the inspection result normal?

YES-1 >> To check malfunction symptom before repair: Refer to 

GI-44, "Intermittent Incident"

.

YES-2 >> Confirmation after repair: INSPECTION END
NO

>> Proceed to 

EC-348, "Diagnosis Procedure"

.

Vehicle speed

More than 30 km/h (19 mph)

Selector lever

Except P or N position

Vehicle speed

More than 30 km/h (19 mph)

Selector lever

Except P or N position

Driving condition

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

ECM

Condition

Voltage

(Approx.)

Connector

+

–

Terminal

E16

115

128

Brake pedal

Slightly depressed

Battery voltage

Fully released

0 V

116

Slightly depressed

0 V

Fully released

Battery voltage

EC-348

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

P1572 ASCD BRAKE SWITCH

Diagnosis Procedure

INFOID:0000000010775245

1.

CHECK DTC PRIORITY

If DTC P1572 is displayed with DTC P0605, perform the trouble diagnosis for DTC P0605.

Is applicable DTC detected?

YES

>> Perform diagnosis of applicable. Refer to 

EC-314, "DTC Description"

.

NO

>> GO TO 2.

2.

CHECK BRAKE PEDAL POSITION SWITCH CIRCUIT

With CONSULT

1.

Turn ignition switch ON.

2.

Select “BRAKE SW1” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

3.

Check “BRAKE SW1” indication as per the following conditions.

Without CONSULT

1.

Turn ignition switch ON.

2.

Check the voltage between ECM harness connector terminals as per the following.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 4.

3.

CHECK STOP LAMP SWITCH CIRCUIT

With CONSULT

1.

Select “BRAKE SW2” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

2.

Check “BRAKE SW2” indication as per the following conditions.

Without CONSULT

1.

Turn ignition switch ON.

2.

Check the voltage between ECM harness connector terminals as per the following.

Monitor item

Condition

Indication

BRAKE SW1

Brake pedal

Slightly de-
pressed

OFF

Fully re-
leased

ON

ECM

Condition

Voltage

(Approx.)

Connector

+

–

Terminal

E16

116

128

Brake pedal

Slightly de-
pressed

0 V

Fully released

Battery voltage

Monitor item

Condition

Indication

BRAKE SW2

Brake pedal

Slightly de-
pressed

ON

Fully re-
leased

OFF

ECM

Condition

Voltage

(Approx.)

Connector

+

–

Terminal