Infiniti QX56 (Z62). Manual - part 1084

SBC-36

< DTC/CIRCUIT DIAGNOSIS >

B2451 SEAT BLT MTR DR CIRC

B2451 SEAT BLT MTR DR CIRC

DTC Logic

INFOID:0000000006237899

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT

1.

Turn ignition switch ON.

2.

Check “Self-diagnostic result” with CONSULT-III.

Is DTC detected?

YES

>> Refer to 

SBC-36, "Diagnosis Procedure"

.

NO

>> Driver side pre-crash seat belt motor system is normal.

Diagnosis Procedure

INFOID:0000000006237900

1.

INSPECTION START

1.

Check “Self-diagnostic result” with CONSULT-III.

2.

Touch “ERASE”.

3.

Perform DTC Confirmation Procedure. Refer to 

SBC-36, "DTC Logic"

.

Is DTC B2451 displayed again?

YES

>> Replace pre-crash seat belt control unit (driver side). Refer to 

SB-6, "SEAT BELT RETRACTOR :

Removal and Installation"

.

NO

>> GO TO 2.

2.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2451

SEAT BLT MTR DR CIRC

Circuit of seat belt motor (driver side) is 
open or shorted

Pre-crash seat belt control unit (driver side) 

B2452 SEAT BLT MTR AS CIRC

SBC-37

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

B2452 SEAT BLT MTR AS CIRC

DTC Logic

INFOID:0000000006237901

DTC DETECTION LOGIC

DTC REPRODUCTION PROCEDURE

1.

SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT

1.

Turn ignition switch ON.

2.

Check “Self-diagnostic result” with CONSULT-III.

Is DTC detected?

YES

>> Refer to 

SBC-37, "Diagnosis Procedure"

.

NO

>> Passenger side pre-crash seat belt motor system is normal.

Diagnosis Procedure

INFOID:0000000006237902

1.

INSPECTION START

1.

Check “Self-diagnostic result” with CONSULT-III.

2.

Touch “ERASE”.

3.

Perform DTC Confirmation Procedure. Refer to 

SBC-37, "DTC Logic"

.

Is DTC B2452 displayed again?

YES

>> Replace pre-crash seat belt control unit (passenger side). Refer to 

SB-6, "SEAT BELT RETRAC-

TOR : Removal and Installation"

.

NO

>> GO TO 2.

2.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2452

SEAT BLT MTR AS CIRC

Circuit of seat belt motor (passenger side) 
is open or shorted

Pre-crash seat belt control unit (passenger 
side) 

SBC-38

< DTC/CIRCUIT DIAGNOSIS >

B2453 BR STROKE SEN CIRC

B2453 BR STROKE SEN CIRC

DTC Logic

INFOID:0000000006237903

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT

1.

Turn ignition switch ON.

2.

Check “Self-diagnostic result” with CONSULT-III.

Is DTC detected?

YES

>> Refer to 

SBC-38, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006237904

1.

CHECK PRE-CRASH SEAT BELT CONTROL UNIT INPUT SIGNAL

1.

Turn ignition switch ON.

2.

Select “BRK PEDAL SNSR1” and “BRK PEDAL SNSR2” in “DATA MONITOR” mode with CONSULT-III. 

3.

Check “BRK PEDAL SNSR1” and “BRK PEDAL SNSR2” indication under the following conditions.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 2.

2.

CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect brake pedal stroke sensor harness connector.

3.

Check voltage between brake pedal stroke sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect pre-crash seat belt control unit (driver side) harness connector.

2.

Check continuity between pre-crash seat belt control unit (driver side) harness connector and brake pedal
stroke sensor harness connector.

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2453

BR STROKE SEN CIRC

Circuit of brake pedal stroke sensor out-
put is open or shorted

• Harness or connectors

(The sensor circuit is open or shorted) 

• Pre-crash seat belt control unit (driver side) 
• Brake pedal stroke sensor

Monitor item

Condition

Voltage (V)

(Approx.)

BRK PEDAL SNSR1

Brake released 

→

 depressed

1 

→

 4

BRK PEDAL SNSR2

4 

→

 1

Brake pedal stroke sensor

Ground

Voltage (V)

(Approx.)

Connector

Terminal

E111

2

5

Pre-crash seat belt control unit (driver side)

Brake pedal stroke sensor

Continuity

Connector

Terminal

Connector

Terminal

B9

10

E111

2

Existed

B2453 BR STROKE SEN CIRC

SBC-39

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

3.

Check continuity between pre-crash seat belt control unit (driver side) harness connector and ground.

Is the inspection result normal?

YES

>> Replace pre-crash seat belt control unit (driver side). Refer to 

SB-6, "SEAT BELT RETRACTOR :

Removal and Installation"

.

NO

>> Repair or replace harness or connector.

4.

CHECK BRAKE PEDAL STROKE SENSOR CIRCUIT

1.

Disconnect pre-crash seat belt control unit (driver side) harness connector.

2.

Check continuity between pre-crash seat belt control unit (driver side) harness connector and brake pedal
stroke sensor harness connector.

3.

Check continuity between pre-crash seat belt control unit harness connector (driver side) and ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace harness or connector.

5.

CHECK BRAKE PEDAL STROKE SENSOR

Refer to 

SBC-39, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace brake pedal stroke sensor. Refer to 

SBC-63, "Removal and Installation"

.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000006237905

COMPONENT PARTS INSPECTION

1.

CHECK BRAKE PEDAL STROKE SENSOR

1.

Turn ignition switch OFF.

2.

Disconnect brake pedal stroke sensor connector. 

3.

Check resistance between brake pedal stroke sensor terminal as per the following.

Pre-crash seat belt control unit (driver side)

Ground

Continuity

Connector

Terminal

B9

10

Not existed

Pre-crash seat belt control unit (driver side)

Brake pedal stroke sensor

Continuity

Connector

Terminal

Connector

Terminal

B9

2

E111

1

Existed

12

3

17

4

Pre-crash seat belt control unit (driver side)

Ground

Continuity

Connector

Terminal

B9

2

Not existed

12

17