Nissan Leaf. Manual - part 242

C1A90 CONTROL MODULE

BR-289

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

G

H

I

J

K

L

M

A

B

BR

N

O

P

NO

>> INSPECTION END

20.

CHECK BCM SYSTEM

With CONSULT

Perform self-diagnosis for “BCM”. Refer to 

BCS-23, "BCM : CONSULT Function (BCM - BCM)"

.

Is any DTC detected?

YES

>> Check the DTC. Refer to 

BCS-48, "DTC Index"

. GO TO 21.

NO

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

BR-510, "Removal and installation"

.

21.

PERFORM SELF-DIAGNOSIS (9)

With CONSULT

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

CAUTION:

Never set the vehicle to READY.

2. Repeat step 1 two or more times.

CAUTION:

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

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

4. 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.

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

CAUTION:

Never set the vehicle to READY.

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

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

8. 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.

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

CAUTION:

Never set the vehicle to READY.

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

11. Release brake pedal.

12. Start CONSULT and perform “BRAKE” self-diagnosis.
Is DTC “C1A90” detected?

YES

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

BR-510, "Removal and installation"

.

NO

>> INSPECTION END

BR-290

< DTC/CIRCUIT DIAGNOSIS >

C1A91 CONTROL MODULE

C1A91 CONTROL MODULE

DTC Logic

INFOID:0000000010123059

DTC DETECTION LOGIC

DTC REPRODUCTION PROCEDURE

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn power switch OFF and

wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

With CONSULT

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

CAUTION:

Never set the vehicle to READY.

2. Start CONSULT and perform “BRAKE” self-diagnosis.
Is DTC “C1A91” detected?

YES

>> Proceed to 

BR-290, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010123060

1.

PERFORM SELF-DIAGNOSIS (1)

With CONSULT

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

CAUTION:

Never set the vehicle to READY.

2. Start CONSULT and perform “BRAKE” self-diagnosis.
“PAST” or “CRNT” shown in self-diagnosis results (“C1A91”)?

YES (“PAST”)>>GO TO 2.

YES (“CRNT”)>>GO TO 6.

NO

>> INSPECTION END

2.

INTERVIEW FROM THE CUSTOMER (1)

Check to see if there is a removal history of 12V battery or 12V battery terminals.
Is there a removal history of 12V battery or 12V battery terminals?

YES

>> GO TO 3.

NO

>> GO TO 6.

3.

INTERVIEW FROM THE CUSTOMER (2)

Check to see if there is a lighting history of the brake system warning lamp (yellow).
Is there a lighting history of the brake system warning lamp (yellow)?

YES

>> GO TO 6.

NO

>> GO TO 4.

4.

INTERVIEW FROM THE CUSTOMER (3)

Check to see if the customer has an experience of feeling unusual braking force (brake pedal operation).

DTC

Display item

Malfunction detection condition

Possible causes

C1A91

IGNITION POWER SUPPLY

A power switch ON signal which is input from BCM 
via CAN communication is input without an input of 
a power switch ON signal which is directly input to 
the electrically-driven intelligent brake unit.

• Harness or connector
• Electrically-driven intelligent 

brake unit

C1A91 CONTROL MODULE

BR-291

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

G

H

I

J

K

L

M

A

B

BR

N

O

P

Does the customer have an experience of feeling unusual braking force?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

PERFORM SELF-DIAGNOSIS (2)

With CONSULT

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

CAUTION:

Never set the vehicle to READY.

2. Repeat step 1 two or more times.

CAUTION:

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

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

4. 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.

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

CAUTION:

Never set the vehicle to READY.

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

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

8. 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.

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

CAUTION:

Never set the vehicle to READY.

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

11. Release brake pedal.

12. Start CONSULT and perform “BRAKE” self-diagnosis.
Is DTC “C1A91” detected?

YES

>> GO TO 6.

NO

>> INSPECTION END [DTC “C1A91” is detected when12V battery terminals are disconnected after

turning the power switch OFF with any door open (including back door) or without waiting 3 min-

utes after closing all doors (including back door).]

6.

CHECK 12V BATTERY

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. Check the 12V battery terminal connections. Refer to 

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

 and

PG-83, "Work Flow"

.

4. Check the 12V battery. Refer to 

PG-83, "Work Flow"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Repair or replace error-detected parts and GO TO 7.

7.

PERFORM SELF-DIAGNOSIS (3)

With CONSULT

1. Connect 12V battery cable to negative terminal.

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

CAUTION:

Never set the vehicle to READY.

3. Repeat step 2 two or more times.

CAUTION:

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

BR-292

< DTC/CIRCUIT DIAGNOSIS >

C1A91 CONTROL MODULE

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

5. 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.

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

CAUTION:

Never set the vehicle to READY.

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

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

9. 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.

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

CAUTION:

Never set the vehicle to READY.

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

12. Release brake pedal.

13. Start CONSULT and perform “BRAKE” self-diagnosis.
Is DTC “C1A91” detected?

YES

>> GO TO 8.

NO

>> INSPECTION END

8.

CHECK CONNECTOR TERMINALS

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, then check for failures of pin

terminals and connections.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Repair or replace error-detected parts and GO TO 9.

9.

PERFORM SELF-DIAGNOSIS (4)

With CONSULT

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

2. Connect 12V battery cable to negative terminal.

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

CAUTION:

Never set the vehicle to READY.

4. Repeat step 3 two or more times.

CAUTION:

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

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

6. 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.

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

CAUTION:

Never set the vehicle to READY.

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

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

10. 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.