Infiniti FX35, FX50 (S51). Manual - part 1591

SBC-22

< DTC/CIRCUIT DIAGNOSIS >

B2455 CONTROL UNIT DR

B2455 CONTROL UNIT DR

Description

INFOID:0000000005241723

• It controls pre-crash seat belt motor according to input signal
• Built in driver side seat belt retractor

DTC Logic

INFOID:0000000005241724

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-22, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005241725

1.

.INSPECTION START

1.

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

2.

Touch “ERASE”.

3.

Perform DTC Confirmation Procedure.
See 

SBC-22, "DTC Logic"

.

Is DTC B2455 displayed again?

YES

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

NO

>> GO TO 2.

2.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2455

CONTROL UNIT DR

Pre-crash seat belt control unit internal circuit malfunction 

Control unit internal malfunction 

B2456 SEAT BLT PWR AS

SBC-23

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

B2456 SEAT BLT PWR AS

Description

INFOID:0000000005241726

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

and reduces the seat belt slack.

• Power supply is supplied constantly from battery power supply.

DTC Logic

INFOID:0000000005241727

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-23, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005241728

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 (passenger side) connector.

3.

Check voltage between pre-crash seat belt control unit (passenger 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 (passenger side) and fusible

link.

3.

CHECK SELF DIAGNOSTIC RESULT

1.

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

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2456

SEAT BLT PWR AS

Pre-crash seat belt control unit power supply cir-
cuit is open or shorted

CAUTION:

Malfunction is judged when 30A (F/L-K) 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

K

Pre-crash seat belt control unit (passenger side)

Ground

Voltage (V)

(Approx.)

Connector

Terminal

Battery voltage

B221

19

SBC-24

< DTC/CIRCUIT DIAGNOSIS >

B2456 SEAT BLT PWR AS

2.

Turn ignition switch ON.

3.

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

4.

Touch “ERASE”.

5.

Perform DTC Confirmation Procedure.
See 

SBC-23, "DTC Logic"

.

Is DTC B2456 displayed again?

YES

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

NO

>> GO TO 4.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

B2457 CONTROL UNIT AS

SBC-25

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

B2457 CONTROL UNIT AS

Description

INFOID:0000000005241729

• It controls pre-crash seat belt motor according to input signal
• Built in passenger side seat belt retractor

DTC Logic

INFOID:0000000005241730

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-25, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005241731

1.

.INSPECTION START

1.

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

2.

Touch “ERASE”.

3.

Perform DTC Confirmation Procedure.
See 

SBC-25, "DTC Logic"

.

Is DTC B2457 displayed again?

YES

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

NO

>> GO TO 2.

2.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2457

CONTROL UNIT AS

Pre-crash seat belt control unit internal circuit malfunction 

Control unit internal malfunction