Infiniti M35/M45 Y50. Manual - part 1037

PRE-CRASH SEAT BELT

SB-19

C

D

E

F

G

I

J

K

L

M

A

B

SB

2. 

CHECK SEAT BELT BUCKLE SWITCH (DRIVER SIDE) HARNESS

1.

Turn ignition switch OFF.

2.

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

3.

Check continuity between pre-crash seat belt control unit har-
ness connector and seat belt buckle switch (driver side) harness
connector.

4.

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

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace harness.

3. 

CHECK LH SEAT BELT SWITCH

Check continuity between seat belt buckle switch (driver side) while
performing the insertion operation to the seat belt buckle.

OK or NG

OK

>> GO TO 4.

NG

>> Replace seat belt buckle switch (driver side).

4. 

CHECK LH SEAT BELT SWITCH GROUND CIRCUIT HARNNES

Check continuity between seat belt buckle switch (driver side) har-
ness connector and ground.

OK or NG

OK

>> Check harness connection.

●

If it is OK, replace pre-crash seat belt control unit.

●

If it is NG, repair or replace malfunction part.

NG

>> Repair or replace harness.

A

B

Continuity 

Pre-crash seat 

belt control unit 

connector

Terminal

Seat belt buckle 

switch (driver side) 

connector

Terminal

B142

10 B203

1

Yes

A

Ground

Continuity 

Pre-crash seat belt 

control unit connector

Terminal

B142

10

No

PHIA1130E

Seat belt buckle 

switch connector 

(driver side) 

Terminal Condition

Continuity 

B203

1

2

When seat belt is unfastened

Yes

When seat belt is fastened

No

PHIA1131E

Terminal

Continuity 

Seat belt buckle switch 

connector (driver side) 

Terminal

Ground

 B203

2

Yes

PHIA1132E

SB-20

PRE-CRASH SEAT BELT

Check Seat Belt Buckle Switch (Passenger Side) Circuit 

NHS0008C

1. 

CHECK PRE-CRASH SEAT BELT CONTROL UNIT INPUT SIGNAL

 With CONSULT-II

Select “SB SW RH SIG” on DATA MONITOR screen, and then make
sure that ON/OFF display changes synchronized with the insertion
operation to the seat belt buckle.

 Without CONSULT-II

1.

Turn ignition switch ON.

2.

Check voltage between seat belt buckle switch (passenger side)
harness connector and ground.

OK or NG

OK

>> Seat belt buckle switch (passenger side) circuit is OK.

NG

>> GO TO 2.

2. 

CHECK SEAT BELT BUCKLE SWITCH (PASSENGER SIDE) HARNESS

1.

Turn ignition switch OFF.

2.

Disconnect pre-crash seat belt control unit and seat belt buckle switch (passenger side) connector.

3.

Check continuity between pre-crash seat belt control unit har-
ness connector and seat belt buckle switch (passenger side)
harness connector.

4.

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

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace harness.

SB SW RH SIG

When passenger seat belt is not fastened

:OFF

When passenger seat belt is fastened

:ON

PHIA0764E

Terminal

Condition

Voltage (V)

(Approx.)

(+)

(–)

Seat belt buckle 

switch connector 
(passenger side) 

Terminal 

B253

1

Ground

When seat belt is 
unfastened

0

When seat belt is 
fastened

5

PHIA1129E

A

B

Continuity 

Pre-crash seat 

belt control unit 

connector

Terminal

Seat belt buckle 

switch (passenger 

side) connector

Terminal

B142

8

 B253

1

Yes

A

Ground

Continuity 

Pre-crash seat belt

 control unit connector

Terminal

B142

8

No

PHIA1133E

PRE-CRASH SEAT BELT

SB-21

C

D

E

F

G

I

J

K

L

M

A

B

SB

3. 

CHECK RH SEAT BELT SWITCH

Check continuity between seat belt buckle switch (passenger side)
while performing the insertion operation to the seat belt buckle.

OK or NG

OK

>> GO TO 4.

NG

>> Replace seat belt buckle (passenger side).

4. 

CHECK RH SEAT BELT SWITCH GROUND CIRCUIT HARNNES

Check continuity between seat belt buckle switch (passenger side)
harness connector and ground.

OK or NG

OK

>> Check harness connection.

●

If it is OK, replace pre-crash seat belt control unit.

●

If it is NG, repair or replace malfunction part.

NG

>> Repair or replace harness.

Check Brake Pedal Stroke Sensor Circuit [B2453]

NHS0008D

1. 

CHECK SELF-DIAGNOSTIC RESULT

 With CONSULT-II

Select “SELF-DIAG RESULTS”, and then make sure that “BR
STROKE SEN CIRC” is displayed.

Without CONSULT-II

When CONSULT-II is not used, omit this inspection, and then GO TO 2.

Displayed B2453?

Yes

>> GO TO 3.

No

>> GO TO 2.

Seat belt buckle 

switch connector
(passenger side)

Terminal Condition

Continuity 

B253

1

2

When seat belt is unfastened

Yes

When seat belt is fastened

No

PHIA1131E

Terminal

Continuity 

Seat belt buckle switch 

connector (passenger side) 

Terminal

Ground

 B253

2

Yes

PHIA1132E

CONSULT-II display

CONSULT-II display code

NO DTC

—

BR STROKE SEN CIRC

B2453

PHIA0769E

SB-22

PRE-CRASH SEAT BELT

2. 

CHECK PRE-CRASH SEAT BELT CONTOROL UNIT INPUT SIGNAL

 With CONSULT-II

Select “B PEDAL SIG1” and “B PEDAL SIG2”, and then make sure that the voltage changes synchronized
with brake pedal operation.

 Without CONSULT-II

1.

Turn ignition switch ON.

2.

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

OK or NG

OK

>> Brake pedal stroke sensor system is normal.

NG

>> GO TO 3.

B PEDAL SIG1

Brake released 

→

 depressed

: Approx. 1 

→

 4V

B PEDAL SIG 2

Brake released 

→

 depressed

: Approx. 4 

→

 1V

PHIA0766E

Terminal

Condition

Voltage (V)

(Approx.)

(+)

(–)

Pre-crash seat 

belt control unit 

connector

Terminal 

B142

16

Ground

Brake released 

→

 

depressed

1 

→

 4

20

4 

→

 1

PHIA1134E