Infiniti G37 Coupe. Manual - part 1077

SBC-16

< COMPONENT DIAGNOSIS >

B2452 SB MOTOR LH CIRC

B2452 SB MOTOR LH CIRC

Description

INFOID:0000000001711980

• It pulls, returns, and maintains according to the motor rotation.
• It is built into the seat belt retractor.
• It is installed to the back of LH center pillar garnish.

DTC Logic

INFOID:0000000001711981

DTC DETECTION LOGIC

DTC REPRODUCTION PROCEDURE

1.

CHECK LH PRE-CRASH SEAT BELT MOTOR CIRCUIT

Check “SELF-DIAG RESULT” of CONSULT-lll.

Is any DTC detected?

YES

>> Refer to 

SBC-16, "Diagnosis Procedure"

.

NO

>> LH pre-crash seat belt motor system is normal.

Diagnosis Procedure

INFOID:0000000001711982

1.

CHECK LH PRE-CRASH SEAT BELT MOTOR HARNESS

1.

Turn the ignition switch OFF.

2.

Disconnect pre-crash seat belt control unit and LH pre-crash seat belt motor connector.

3.

Does continuity between pre-crash seat belt control unit harness connector terminals 4, 6 and LH pre-
crash seat belt motor harness connector terminals 1, 2 exist?

4.

Does continuity between pre-crash seat belt control unit harness connector terminals 4, 6 and ground
exist?

Is the inspection result normal?

YES

>> Refer to 

SBC-16, "Component Inspection"

.

NO

>> Repair or replace harness between pre-crash seat belt control unit and LH pre-crash seat belt

motor.

Component Inspection

INFOID:0000000001711983

COMPONENT PARTS INSPECTION

1.

CHECK LH PRE-CRASH SEAT BELT MOTOR

Does continuity between LH seat belt terminals 1 and 2 exist?

Is the inspection result normal?

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2452

Seat belt motor system LH

Circuit of seat belt motor (LH) is 
open or shorted

• Open circuit, short circuit to bat-

tery, and short circuit to ground in 
seat belt motor (LH) harness 

• ECU internal malfunction 

1 - 6

Existed

2 - 4

Existed

4 - Ground

Not existed

6 - Ground

Not existed

1 - 2

Existed

B2452 SB MOTOR LH CIRC

SBC-17

< COMPONENT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

YES

>> Replace pre-crash seat belt control unit.

NO

>> Replace LH pre-crash seat belt motor.

SBC-18

< COMPONENT DIAGNOSIS >

B2453 BR STROK SEN CIRC

B2453 BR STROK SEN CIRC

Description

INFOID:0000000001711984

• It changes voltage according to brake pedal depressed amount and sends the signal to pre-crash seat belt

control unit.

• There are 2 signals (brake pedal stroke sensor 1 and 2) sent from the brake pedal stroke sensor. Pre-crash

seat belt control unit will judge the stroke amount and the speed of the brake pedal according to the voltage
of the signal sent by each side.

• It is installed to back of driver instrument panel (lower).

DTC Logic

INFOID:0000000001711985

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

CHECK LH PRE-CRASH SEAT BELT MOTOR CIRCUIT

Check “SELF-DIAG RESULT” of CONSULT-lll.

Is any DTC detected?

YES

>> Refer to Check 2 of 

SBC-18, "Diagnosis Procedure"

.

NO

>> Refer to Check 1 of 

SBC-18, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000001711986

1.

CHECK PRE-CRASH SEAT BELT CONTROL UNIT INPUT SIGNAL

Select “B-pedal sensor SIG1” and “B-pedal sensor SIG2”, and then check that the voltage changes are syn-
chronized with brake pedal operation.

Is the inspection result normal?

YES

>> Brake pedal stroke sensor system is normal.

NO

>> GO TO 2.

2.

CHECK BRAKE PEDAL STROKE SENSOR HARNESS

1.

Turn the ignition switch OFF.

2.

Disconnect pre-crash seat belt control unit and brake pedal stroke sensor connector.

3.

Does continuity between pre-crash seat belt control unit harness connector terminals 16, 18, 20, 21 and
brake pedal stroke sensor harness connector terminals 1, 2, 3, 4 exist?

4.

Does continuity between pre-crash seat belt control unit harness connector terminals 16, 18, 20, 21 and
ground exist?

DTC No.

Self-diagnosis item

DTC Detection Condition

Possible causes

B2453

B-pedal sensor sys-

tem

Circuit of brake pedal stroke sensor 
output is open or shorted

• Open circuit, short circuit to battery, and short 

circuit to ground in brake pedal stroke sensor 
harness 

• ECU internal malfunction 

B-pedal sensor SIG1

Brake released 

→

 depressed

Approx. 1 

→

 4V

B-pedal sensor SIG2

Brake released 

→

 depressed

Approx. 4 

→

 1V

16 - 1

Existed

18 - 2

Existed

20 - 3

Existed

21 - 4

Existed

B2453 BR STROK SEN CIRC

SBC-19

< COMPONENT DIAGNOSIS >

C

D

E

F

G

I

J

K

L

M

A

B

SBC

N

O

P

Is the inspection result normal?

YES

>> GO TO 3.

NO

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

3.

CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY

1.

Connect pre-crash seat belt control unit connector.

2.

Turn the ignition switch ON.

3.

Check that voltage between pre-crash seat belt control unit harness connector terminal 18 and ground is
normal.

Is the inspection result normal?

YES

>> Refer to 

SBC-19, "Component Inspection"

.

NO

>> Replace pre-crash seat belt control unit.

Component Inspection

INFOID:0000000001711987

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.

Is the inspection result normal?

YES

>> Brake pedal stroke sensor system is normal.

NO

>> Replace brake pedal stroke sensor.

16 - Ground

Not existed

18 - Ground

Not existed

20 - Ground

Not existed

21 - Ground

Not existed

18 - Ground

Approx. 5V

Terminal

Measuring condition

Resistance (K

Ω

)

2

1

Brake released 

→

 depressed

Approx. 1.0 

→

 0.2

3

Brake released 

→

 depressed

Approx. 0.2 

→

 1.0