Nissan Leaf. Manual - part 287

U1511 BRAKE POWER SUPPLY BACKUP UNIT COMMUNICATION

BR-469

< DTC/CIRCUIT DIAGNOSIS >

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7. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

8. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

9. Start CONSULT and erase self-diagnosis result of “BRAKE”.

10. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

11. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

12. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

13. Depress brake pedal by 100 mm (3.94 in) or more, and hold the position for 5 seconds or more.

14. Release brake pedal.

15. Start CONSULT and perform “BRAKE” self-diagnosis.
Is DTC “U1511” detected?

YES

>> GO TO 19.

NO

>> INSPECTION END

19.

REPLACE BRAKE POWER SUPPLY BACKUP UNIT

With CONSULT

1. Replace the brake power supply backup unit. Refer to 

BR-513, "Removal and Installation"

.

2. Connect the electrically-driven intelligent brake unit harness connector.

3. Connect 12V battery cable to negative terminal.

4. Turn the power switch OFF to ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

5. Repeat step 4 two or more times.

CAUTION:

Be sure to wait for 5 seconds or more after turning the power switch OFF.

6. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

7. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

8. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

9. Start CONSULT and erase self-diagnosis result of “BRAKE”.

10. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

11. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

12. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

13. Depress brake pedal by 100 mm (3.94 in) or more, and hold the position for 5 seconds or more.

14. Release brake pedal.

15. Start CONSULT and perform “BRAKE” self-diagnosis.
Is DTC “U1511” detected?

YES

>> Replace the electrically-driven intelligent brake unit. Refer to 

BR-510, "Removal and installation"

.

NO

>> INSPECTION END

BR-470

< DTC/CIRCUIT DIAGNOSIS >

POWER SUPPLY AND GROUND CIRCUIT

POWER SUPPLY AND GROUND CIRCUIT

Diagnosis Procedure

INFOID:0000000010123101

1.

CHECK POWER OF ELECTRICALLY-DRIVEN BRAKE UNIT WHEN POWER SWITCH IS ON

1. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

2. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

3. Disconnect 12V battery cable from negative terminal. Refer to 

BR-6, "Precaution for Removing 12V Bat-

tery"

.

4. Disconnect the electrically-driven intelligent brake unit harness connector.

5. Connect 12V battery cable to negative terminal.

6. Check the voltage between the electrically-driven intelligent brake unit harness connector and ground.

7. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

8. Check the voltage between the electrically-driven intelligent brake unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

CHECK POWER CIRCUIT OF ELECTRICALLY-DRIVEN BRAKE UNIT WHEN POWER SWITCH IS ON

1. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

2. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

3. Disconnect 12V battery cable from negative terminal. Refer to 

BR-6, "Precaution for Removing 12V Bat-

tery"

.

4. Check the 15A fuse (#62).

5. Disconnect IPDM E/R harness connector.

6. Check the continuity between electrically-driven intelligent brake unit harness connector and IPDM E/R

harness connector.

7. Check the continuity between electrically-driven intelligent brake unit harness connector and ground.

Electrically-driven intelligent brake unit

—

Voltage

(Approx.)

Connector

Terminal

E34

26

Ground

0 V

Electrically-driven intelligent brake unit

—

Voltage

(Approx.)

Connector

Terminal

E34

26

Ground

10 

− 16 V

Electrically-driven intelligent brake 

unit

IPDM E/R

Continuity

Connector

Terminal

Connector

Terminal

E34

26

E15

62

Existed

Electrically-driven intelligent brake 

unit

—

Continuity

Connector

Terminal

E34

26

Ground

Not existed

POWER SUPPLY AND GROUND CIRCUIT

BR-471

< DTC/CIRCUIT DIAGNOSIS >

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Is the inspection result normal?

YES

>> Perform trouble diagnosis for power ON power supply. Refer to 

PG-26, "Wiring Diagram—On

Power Supply—"

.

NO

>> Repair or replace error-detected parts.

3.

CHECK 12V BATTERY POWER SUPPLY OF ELECTRICALLY-DRIVEN INTELLIGENT BRAKE UNIT

1. Turn the power switch OFF to exit CONSULT.

2. Connect 12V battery cable to negative terminal.

3. Check the voltage between the electrically-driven intelligent brake unit harness connector and ground.

4. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

5. Check the voltage between the electrically-driven intelligent brake unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

CHECK 12V BATTERY POWER SUPPLY CIRCUIT OF ELECTRICALLY-DRIVEN INTELLIGENT BRAKE

UNIT

1. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

2. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

3. Disconnect 12V battery cable from negative terminal. Refer to 

BR-6, "Precaution for Removing 12V Bat-

tery"

.

4. Check the 60A fusible link (#F).

5. Check the continuity and for short circuit between harness connector terminal 1 of electrically-driven intel-

ligent brake unit and 60A fusible link (#F).

6. Check the continuity and for short circuit between harness connector terminal 2 of electrically-driven intel-

ligent brake unit and 60A fusible link (#F).

7. Check the 15A fuse (#75).

8. Check the continuity and for short circuit between harness connector terminal 28 of electrically-driven

intelligent brake unit and 15A fuse (#75).

Is the inspection result normal?

YES

>> Perform trouble diagnosis for 12V battery power supply. Refer to 

PG-15, "Wiring Diagram — Bat-

tery Power Supply —"

.

NO

>> Repair or replace error-detected parts.

5.

CHECK 12V BATTERY POWER SUPPLY OF BRAKE POWER SUPPLY BACKUP UNIT

1. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

Electrically-driven intelligent brake 

unit

—

Voltage

(Approx.)

Connector

Terminal

E34

1

Ground

10 

− 16 V

2

28

Electrically-driven intelligent brake 

unit

—

Voltage

(Approx.)

Connector

Terminal

E34

1

Ground

10 

− 16 V

2

28

BR-472

< DTC/CIRCUIT DIAGNOSIS >

POWER SUPPLY AND GROUND CIRCUIT

2. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

3. Disconnect 12V battery cable from negative terminal. Refer to 

BR-6, "Precaution for Removing 12V Bat-

tery"

.

4. Disconnect brake power supply backup unit harness connector.

5. Connect 12V battery cable to negative terminal.

6. Check the voltage between brake power supply backup unit harness connector and ground.

7. Turn the power switch ON without depressing the brake pedal.

CAUTION:

Never set the vehicle to READY.

8. Check the voltage between brake power supply backup unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

CHECK 12V BATTERY POWER CIRCUIT OF BRAKE POWER SUPPLY BACKUP UNIT

1. Turn the power switch OFF to exit CONSULT, and disconnect CONSULT from data link connector.

2. Close all doors (including back door), check that the room lamp is OFF, get out of the vehicle, and wait for

3 minutes or more with all doors closed.

CAUTION:

Never operate the vehicle while waiting.

3. Disconnect 12V battery cable from negative terminal. Refer to 

BR-6, "Precaution for Removing 12V Bat-

tery"

.

4. Check the 15A fuse (#82).

5. Check the continuity and for short circuit between harness connector terminal 6 of brake power supply

backup unit and 15A fuse (#82).

Is the inspection result normal?

YES

>> Perform trouble diagnosis for 12V battery power supply. Refer to 

PG-15, "Wiring Diagram — Bat-

tery Power Supply —"

.

NO

>> Repair or replace error-detected parts.

7.

CHECK ELECTRICALLY-DRIVEN INTELLIGENT BRAKE UNIT GROUND

Check the continuity between electrically-driven intelligent brake unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Repair or replace error-detected parts.

8.

CHECK BRAKE POWER SUPPLY BACKUP UNIT GROUND

Check the continuity between brake power supply backup unit harness connector and ground.

Brake power supply backup unit

—

Voltage

(Approx.)

Connector

Terminal

B15

6

Ground

10 

− 16 V

Brake power supply backup unit

—

Voltage

(Approx.)

Connector

Terminal

B15

6

Ground

10 

− 16 V

Electrically-driven intelligent brake 

unit

—

Continuity

Connector

Terminal

E34

32

Ground

Existed