Infiniti QX56 (Z62). Manual - part 1182

SEC-118

< DTC/CIRCUIT DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

B26F9 CRANKING REQUEST CIRCUIT

B26F9 CRANKING REQUEST CIRCUIT

DTC Logic

INFOID:0000000006226276

DTC DETECTION LOGIC

NOTE:
• DTC B26F9 can be detected even though the related circuit is not used in this vehicle.
• If DTC B26F9 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to

BCS-70, "DTC Logic"

.

• If DTC B26F9 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer to

BCS-71, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION

1.

Start engine and wait 2 seconds or more at idle speed.

2.

Drive vehicle for 2 seconds or more.

3.

Check DTC in “Self Diagnostic Result” mode of “BCM” using CONSULT-III. 

Is DTC detected?

YES

>> Go to 

SEC-118, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006226277

1.

CHECK CRANKING REQUEST SIGNAL

1.

Turn ignition switch ON.

2.

Check voltage between BCM harness connector and ground under the following conditions.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

CHECK CRANKING REQUEST SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect BCM connector.

3.

Disconnect ECM connector.

4.

Check continuity between BCM harness connector and ECM harness connector.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

B26F9

CRANK REQ CIR SHORT

BCM detects that the status of the following 
signals does not match.
• Cranking request signal from ECM
• Starter control relay control signal from 

ECM (CAN)

• Harness or connectors 

(Can communication line is open or 
shorted.)

• Harness or connectors 

(Cranking request signal circuit is open 
or shorted.)

• ECM
• BCM

(+)

(–)

Condition

Voltage (V)

(Approx.)

BCM

Connector

Terminal

M69

64

Ground

Ignition switch ON

• Engine: Stopped
• Selector lever position: P

0

• Engine: Stopped
• Selector lever position: 

Other than P

12

Engine running

12

B26F9 CRANKING REQUEST CIRCUIT

SEC-119

< DTC/CIRCUIT DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

C

D

E

F

G

H

I

J

L

M

A

B

SEC

N

O

P

5.

Check continuity between BCM harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness.

3.

REPLACE BCM

1.

Replace BCM. Refer to 

BCS-81, "Removal and Installation"

.

2.

Perform initialization of BCM and registration of all Intelligent Keys using CONSULT-III.
For initialization and registration procedures, refer to CONSULT-III Operation Manual NATS-IVIS/NVIS.

3.

Perform DTC CONFIRMATION PROCEDURE for DTC B26F9. Refer to 

SEC-118, "DTC Logic"

.

Is DTC detected?

YES

>> GO TO 4.

NO

>> INSPECTION END

4.

REPLACE ECM

1.

Replace ECM. Refer to 

EC-535, "Removal and Installation"

.

2.

Perform “ADDITIONAL SERVICE WHEN REPLACING ECM”. Refer to 

EC-143, "Work Procedure"

.

>> INSPECTION END

BCM

ECM

Continuity

Connector

Terminal

Connector

Terminal

M69

64

E80

165

Existed

BCM

Ground

Continuity

Connector

Terminal

M69

64

Not existed

SEC-120

< DTC/CIRCUIT DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

B26FA CRANKING REQUEST CIRCUIT

B26FA CRANKING REQUEST CIRCUIT

DTC Logic

INFOID:0000000006226278

DTC DETECTION LOGIC

NOTE:
• DTC B26FA can be detected even though the related circuit is not used in this vehicle.
• If DTC B26FA is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to

BCS-70, "DTC Logic"

.

• If DTC B26FA is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer to

BCS-71, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION

1.

Start engine and wait 2 seconds or more at idle speed.

2.

Drive vehicle for 2 seconds or more.

3.

Check DTC in “Self Diagnostic Result” mode of “BCM” using CONSULT-III. 

Is DTC detected?

YES

>> Go to 

SEC-120, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006226279

1.

CHECK CRANKING REQUEST SIGNAL

1.

Turn ignition switch ON.

2.

Check voltage between BCM harness connector and ground under the following conditions.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

CHECK CRANKING REQUEST SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect BCM connector.

3.

Disconnect ECM connector.

4.

Check continuity between BCM harness connector and ECM harness connector.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

B26FA

CRANK REQ CIR OPEN

BCM detects that the status of the following 
signals does not match.
• Cranking request signal from ECM
• Starter control relay control signal from 

ECM (CAN)

• Harness or connectors 

(Can communication line is open or 
shorted.)

• Harness or connectors 

(Cranking request signal circuit is open 
or shorted.)

• BCM
• ECM

(+)

(–)

Condition

Voltage (V)

(Approx.)

BCM

Connector

Terminal

M69

64

Ground

Ignition switch ON

• Engine: Stopped
• Selector lever position: P

0

• Engine: Stopped
• Selector lever position: 

Other than P

12

Engine running

12

B26FA CRANKING REQUEST CIRCUIT

SEC-121

< DTC/CIRCUIT DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

C

D

E

F

G

H

I

J

L

M

A

B

SEC

N

O

P

5.

Check continuity between BCM harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness.

3.

REPLACE BCM

1.

Replace BCM. Refer to 

BCS-81, "Removal and Installation"

.

2.

Perform initialization of BCM and registration of all Intelligent Keys using CONSULT-III.
For initialization and registration procedures, refer to CONSULT-III Operation Manual NATS-IVIS/NVIS.

3.

Perform DTC CONFIRMATION PROCEDURE for DTC B26FA. Refer to 

SEC-120, "DTC Logic"

.

Is DTC detected?

YES

>> GO TO 4.

NO

>> INSPECTION END

4.

REPLACE ECM

1.

Replace ECM. Refer to 

EC-535, "Removal and Installation"

.

2.

Perform “ADDITIONAL SERVICE WHEN REPLACING ECM”. Refer to 

EC-143, "Work Procedure"

.

>> INSPECTION END

BCM

ECM

Continuity

Connector

Terminal

Connector

Terminal

M69

64

E80

165

Existed

BCM

Ground

Continuity

Connector

Terminal

M69

64

Not existed