Infiniti QX56 (Z62). Manual - part 1086

SBC-44

< DTC/CIRCUIT DIAGNOSIS >

B2457 CONTROL UNIT AS

B2457 CONTROL UNIT AS

DTC Logic

INFOID:0000000006237912

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-44, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006237913

1.

.INSPECTION START

1.

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

2.

Touch “ERASE”.

3.

Perform DTC Confirmation Procedure.
See 

SBC-44, "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-40, "Intermittent Incident"

.

>> INSPECTION END

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2457

CONTROL UNIT AS

Pre-crash seat belt control unit (passenger side) in-
ternal circuit malfunction 

Pre-crash seat belt control unit (passenger 
side) 

B2458 LOCAL COMM

SBC-45

< DTC/CIRCUIT DIAGNOSIS >

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B2458 LOCAL COMM

DTC Logic

INFOID:0000000006237914

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-45, "Diagnosis Procedure"

.

NO

>> INSPECTIN END

Diagnosis Procedure

INFOID:0000000006237915

1.

CHECK POWER SUPPLY AND GROUND CIRCUIT

Check pre-crash seat belt control unit power supply and ground circuit. Refer to 

SBC-43, "Diagnosis Proce-

dure"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace malfunctioning parts.

2.

CHECK LOCAL COMMUNICATION LINE CIRCUIT

1.

Turn ignition switch OFF.

2.

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

3.

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

4.

Check continuity 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 or connector.

3.

REPLACE PRE-CRASH SEAT BELT CONTROL UNIT (PASSENGER SIDE)

1.

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

SB-6, "SEAT BELT RETRACTOR :

Removal and Installation"

.

2.

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

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2458

LOCAL COMM

Receipt of a malfunction signal between pre-
crash seat belt control unit (driver side) and 
pre-crash seat belt control unit (passenger 
side)

• Harness or connectors

[The pre-crash seat belt control unit (driver side) 
and pre-crash seat belt (passenger side) circuit 
is open or shorted]

• Pre-crash seat belt control unit (driver side)
• Pre-crash seat belt control (passenger side)

Pre-crash seat belt control unit (driver side)

Pre-crash seat belt control unit (passenger side)

Continuity

Connector

Terminal

Connector

Terminal

B9

8

B231

8

Existed

16

16

Pre-crash seat belt control unit (driver side)

Ground

Continuity

Connector

Terminal

B9

8

Not existed

16

SBC-46

< DTC/CIRCUIT DIAGNOSIS >

B2458 LOCAL COMM

Is DTC detected?

YES

>> GO TO 4.

NO

>> INSPECTION END

4.

REPLACE PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE)

1.

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

SB-6, "SEAT BELT RETRACTOR :

Removal and Installation"

.

2.

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

Is DTC detected?

YES

>> GO TO 5.

NO

>> INSPECTION END

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

B2461 VHCL SPEED SIGNAL

SBC-47

< DTC/CIRCUIT DIAGNOSIS >

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B2461 VHCL SPEED SIGNAL

Description

INFOID:0000000006237916

Inputs the vehicle speed signal from combination meter via CAN communication.

DTC Logic

INFOID:0000000006237917

DTC DETECTION LOGIC

NOTE:
If DTC B2461 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to 

SBC-

35, "DTC 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-47, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006237918

1.

CHECK COMBINATION METER

Check combination meter. Refer to 

MWI-57, "Work flow"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace malfunctioning parts.

2.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2461

VHCL SPEED SIGNAL

Receipt of a malfunction signal of the vehicle speed signal

Combination meter