Infiniti FX35, FX50 (S51). Manual - part 1590

SBC-18

< DTC/CIRCUIT DIAGNOSIS >

B2453 BR STROKE SEN CIRC

3.

CHECK BRAKE PEDAL STROKE SENSOR CIRCUIT

1.

Disconnect pre-crash seat belt control unit connector.

2.

Check continuity between pre-crash seat belt control unit harness connector and brake pedal stroke sen-
sor harness connector.

3.

Check continuity between pre-crash seat belt control unit harness connector and ground.

Is the inspection result normal?

YES

>> Refer to 

SBC-18, "Component Inspection"

.

NO

>> Repair or replace harness between pre-crash seat belt control unit and brake pedal stroke sensor.

4.

CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect pre-crash seat belt control unit (driver side) 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 (driver side) and ground.

Is the inspection result normal?

YES

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

NO

>> Repair or replace harness between pre-crash seat belt control unit and brake pedal stroke sensor.

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005241719

COMPONENT PARTS INSPECTION

1.

CHECK BRAKE PEDAL STROKE SENSOR

Check that continuity between brake pedal stroke sensor terminal 2 and terminals 1 and 3 is normal when per-
forming the brake operation.

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

10

12

17

Pre-crash seat belt control unit (driver side)

Brake pedal stroke sensor

Continuity

Connector

Terminal

Connector

Terminal

B9

10

E111

2

Existed

Pre-crash seat belt control unit (driver side)

Ground

Continuity

Connector

Terminal

B9

10

Not existed

B2453 BR STROKE SEN CIRC

SBC-19

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

Is the inspection result normal?

YES

>> Brake pedal stroke sensor system is normal.

NO

>> Replace brake pedal stroke sensor.

Brake pedal stroke sensor

Condition

Resistance (K

Ω

)

(Approx.)

Terminal

2

1

Brake released 

→

 depressed

1.0 

→

 0.2

3

0.2 

→

 1.0

SBC-20

< DTC/CIRCUIT DIAGNOSIS >

B2454 SEAT BLT PWR DR CIRC

B2454 SEAT BLT PWR DR CIRC

Description

INFOID:0000000005241720

• When control unit activates pre-crush seat belt system, it retracts the shoulder belt with the electric motor

and reduces seat belt slack.

• Power supply is supplied constantly from battery power supply.

DTC Logic

INFOID:0000000005241721

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-20, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005241722

1.

CHECK FUSE AND FUSIBLE LINK

Check that the following fuse and fusible link are not blown.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace the blown fuse or fusible link after repairing the affected circuit if a fuse or fusible link is

blown.

2.

CHECK PRE-CRASH SEAT BELT MOTOR POWER SUPPLY

1.

Turn ignition switch OFF.

2.

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

3.

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

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness between pre-crash seat belt control unit and fusible link.

3.

CHECK SELF DIAGNOSTIC RESULT

1.

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

2.

Turn ignition switch ON.

3.

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

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2454

SEAT BLT PWR DR 
CIRC

Motor power supply circuit is open or shorted

CAUTION:

Malfunction is judged when 30A (F/L-J) fusible 
link blows out even if motor power supply cir-
cuit is not malfunctioning. 

• Open circuit and short circuit to 

ground in drive circuit power supply 
harness 

• Control unit internal malfunction 

Terminal No.

Signal name

Fuse and fusible link No.

19

Battery power supply

J

Pre-crash seat belt control unit (driver side)

Ground

Voltage (V)

(Approx.)

Connector

Terminal

Battery voltage

B9

19

B2454 SEAT BLT PWR DR CIRC

SBC-21

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

4.

Touch “ERASE”.

5.

Perform DTC Confirmation Procedure.
See 

SBC-20, "DTC Logic"

.

Is DTC B2454 displayed again?

YES

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

NO

>> GO TO 4.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END