Infiniti M35/M45 Y50. Manual - part 1036

PRE-CRASH SEAT BELT

SB-15

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Preliminary Check

NHS00086

PRE-CRASH SEAT BELT OPERATION INSPECTION

WARNING:

●

The following tests should be performed in a safe, open place that is free of traffic and obstacles.

●

The tests should be performed on a dry, paved road. Do not attempt the tests on wet or unpaved
road, open road, or highway. (This may cause an accident or personal injury.)

●

Driver and passenger assume it will not operate and prepare themselves accordingly.

1.

Tighten driver and passenger seat belts.

2.

Drive at approximately 25 km/h (16 MPH).

3.

Notify passenger of a sudden stop. Driver and passenger prepare themselves for the possibility of
system not operating. Then, driver fully depresses the brake pedal to stop suddenly.

4.

Make sure that the shoulder of the seat belt is pulled while braking.

Diagnoses Symptom Chart

NHS00087

Check CAN Communication Circuit [U1000]

NHS00088

1. 

CHECK SELF-DIAGNOSTIC RESULT

CAUTION:

If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication. 

 With CONSULT-II

1.

Connect CONSULT-II, and turn ignition switch ON.

2.

Touch “PRECRASH SEATBELT” on “SELECT SYSTEM”
screen.

3.

Touch “SELF-DIAG RESULTS” on “SELECT DIAG MODE”
screen.

4.

Check display content in self-diagnostic results.

Displayed U1000?

Yes

>> GO TO 

LAN-50, "CAN System Specification Chart"

 .

No

>> Inspection END.

Symptom

Diagnosis procedure

Reference

page

All functions of pre-crash seat belt system 
does not operate.

1. Check ignition power supply circuit 

SB-16

2. Check motor power supply and ground circuit [B2454]

SB-16

3. Check CAN communication circuit

SB-15

4. Replace pre-crash seat belt control unit

SB-28

Driver side pre-crash seat belt system does 
not operate.

1. Check seat belt buckle switch (driver side) circuit 

SB-18

2. Check pre-crash seat belt motor LH circuit [B2452]

SB-24

3. Replace pre-crash seat belt control unit

SB-28

Passenger side pre-crash seat belt system 
does not operate.

1. Check seat belt buckle switch (passenger side) circuit 

SB-20

2. Check pre-crash seat belt motor RH circuit [B2451]

SB-26

3. Replace pre-crash seat belt control unit

SB-28

Pre-crash seat belt system does not operate 
during emergency brake operation.

1. Check CAN communication circuit [U1000]

SB-15

2. Check brake pedal stroke sensor circuit [B2453]

SB-21

3. Check brake pedal stroke sensor shield wire circuit 

SB-27

4. Replace pre-crash seat belt control unit

SB-28

PHIA0772E

SB-16

PRE-CRASH SEAT BELT

Check Ignition Power Supply Circuit 

NHS00089

1. 

CHECK FUSE

Check 10A fuse [No.15, located in fuse block (J/B)].
NOTE:
Refer to 

SB-3, "Component Parts and Harness Connector Location"

 .

OK or NG

OK

>> GO TO 2.

NG

>> If fuse is blown out, be sure to eliminate cause of malfunction before installing new fuse. Refer to

PG-3, "POWER SUPPLY ROUTING CIRCUIT"

 .

2. 

CHECK IGNITION POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect pre-crash seat belt control unit connector.

3.

Turn ignition switch ON.

4.

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

OK or NG

OK

>> Ignition power supply circuit is OK.

NG

>> Check pre-crash seat belt control unit ignition power supply circuit harness.

Check Motor Power Supply and Ground Circuit [B2454]

NHS0008A

1. 

CHECK FUSE

Check 30A fusible link (letter G , located in the fuse and fusible link box).

NOTE:
Refer to 

SB-3, "Component Parts and Harness Connector Location"

 .

OK or NG

OK

>> GO TO 2.

NG

>> If fuse is blown out, be sure to eliminate cause of malfunction before installing new fuse. Refer to

PG-3, "POWER SUPPLY ROUTING CIRCUIT"

 .

Terminal

Voltage (V)

(Approx.)

(+)

(–)

Pre-crash seat 

belt control unit 

connector

Terminal 

B142

13 Ground

Battery 

voltage

PHIA1126E

PRE-CRASH SEAT BELT

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2. 

CHECK SELF-DIAGNOSTIC RESULT

 With CONSULT-II

Select “SELF-DIAG RESULTS” and then make sure the “MOTOR
PWR SUP CIRC” is displayed.

Without CONSULT-II

When CONSULT-II is not used, omit this inspection, and then GO TO 3.

Displayed B2454?

Yes

>> GO TO 3.

No

>> Motor power supply system is normal.

3. 

CHECK MOTOR POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect pre-crash seat belt control unit connector.

3.

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

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace harness.

4. 

CHECK PRE-CRASH SEAT BELT CONTROL UNIT GROUND CIRCUIT

1.

Disconnect pre-crash seat belt control unit connector.

2.

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

OK or NG

OK

>> Motor power supply and ground circuit is OK.

NG

>> Repair or replace harness.

CONSULT-II display

CONSULT-II display code

NO DTC

—

MOTOR PWR SUP CIRC

B2454

PHIA0770E

Terminal

Voltage (V)

(Approx.)

(+)

(–)

Pre-crash seat 

belt control unit 

connector

Terminal 

B142

2

Ground

Battery voltage

PHIA1127E

Terminal

Continuity 

Pre-crash seat 

belt control unit 

connector

Terminal 

Ground

B142

5 

Yes

26

PHIA1128E

SB-18

PRE-CRASH SEAT BELT

Check Seat Belt Buckle Switch (Driver Side) Circuit 

NHS0008B

1. 

CHECK PRE-CRASH SEAT BELT CONTROL UNIT INPUT SIGNAL

 With CONSULT-II

Select “SB SW LH SIG” on DATA MONITOR screen, and then make sure that ON/OFF display changes syn-
chronized 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 (driver side) har-
ness connector and ground.

OK or NG

OK

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

NG

>> GO TO 2.

SB SW LH SIG

When driver seat belt is not fastened

: OFF

When driver seat belt is fastened

: ON

PHIA0765E

Terminal

Condition

Voltage (V)

(Approx.)

(+)

(–)

Seat belt buckle 

switch connector 

(driver side)

Terminal 

B203

1

Ground

When seat belt is 
unfastened

0

When seat belt is 
fastened

Battery 
voltage

PHIA1129E