brake sensor INFINITI M35 2006 Factory Service Manual

PRE-CRASH SEAT BELT
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Revision: 2006 January2006 M35/M45
PRE-CRASH SEAT BELTPFP:98845
Component Parts and Harness Connector LocationNHS0007X
System DescriptionNHS0007Y
Pre-crash seat belt system is adapted to front seat belts RH/LH.
When the pre-crash seat belt control unit judges the emergency braking operation, it gives the sense of
security by the motor built into the pre-crash seat belt retracting the shoulder belt and suppressing the
crew's posture change. Also, it eases the damage of the collision.
PHIA1123E
1. Fuse block (J/B) 2.Fuse, fusible link and relay block
(J/B)3.Pre-crash seat belt control unit B142
(View with the trunk side finisher LH
removed)
4.Brake pedal stroke sensor E125
(View with the instrument driver
lower panel removed)5.Pre-crash seat belt motor B32 (LH),
B8 (RH)
(View with the center pillar lower
garnish removed)6.Seat belt buckle switch B203 (driver
seat) B253 (passenger seat)

SB-4
PRE-CRASH SEAT BELT
Revision: 2006 January2006 M35/M45
FUNCTION DESCRIPTION
Operation condition
Pre-crash seat belt operates under the following conditions.
Operation prohibition condition
If operation condition is satisfied, pre-crash seat belt does not operate under the following conditions.
*1 :When pre-crash seat belt doesn't operate after it continuously operates 3 times or more, operation can be performed again by stop-
ping operation for approximately 7 minutes.
*
2 : Refer to SB-4, "FAIL-SAFE MODE" for details of fail-safe mode.
FAIL-SAFE MODE
When a malfunction occurs in the following system, the pre-crash seat belt function is controlled according to
the malfunctioning parts.
Also, seat belt warning lamp blinks with fastening driver seat belt when the following malfunction occurs.
Seat Belt Warning Lamp Illumination Pattern
NOTE:
The seat belt warning lamp illumination system shown above operates only when the air bag system does not
turn on the seat belt warning lamp. The air bag system turns on the seat belt warning lamp, depending on the
conditions of passenger being on and the passenger seat belt fastening.
ConditionWhen the brake pedal is depressed more than a certain extent
When operation prohibition condition is not satisfied
Condition
When seat belt is not fastened (Only the seat belt that is not fastened does not operate.)
When vehicle is moving backwards
When the vehicle speed is 15 km/h (9 MPH) or less
When pre-crash seat belt continuously operates 3 times or more *1
At fail-safe condition *2
Malfunctioning parts Control contents
Brake pedal stroke sensor system malfunction Pre-crash seat belt RH/LH do not activate when emergency brake operates.
Seat belt motor RH malfunction Pre-crash seat belt RH does not activate.
Seat belt motor LH malfunction Pre-crash seat belt LH does not activate.
Motor power supply circuit malfunction Pre-crash seat belt RH/LH do not activate.
PHIA1142E

PRE-CRASH SEAT BELT
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Revision: 2006 January2006 M35/M45
Terminals and Reference Value for Pre-Crash Seat Belt Control UnitNHS00083
Work FlowNHS00084
1. Check the symptom and customer's requests.
2. Understand the system description. Refer to SB-3, "
System Description" .
3. Perform the preliminary check. Refer to SB-16, "
Preliminary Check" .
4. Check the self-diagnosis, results using CONSULT-II. Refer to SB-14, "
CONSULT-II Function (PRECRASH
SEATBELT)" .
5. Based on the trouble diagnosis chart, repair or replace the cause of the malfunction. Refer to SB-16,
"Diagnoses Symptom Chart" .
6. Does pre-crash seat belt system operate normally?
OK: GO TO 7.
NG: GO TO 4.
7. INSPECTION END
Terminal Wire Color Item ConditionVoltage [V]
(Approx.)
1G/RSeat belt motor RH release direction
signalSeat belt motor RH operation Battery voltage
Other than above 0
2 W Power source (BAT) – Battery voltage
3G/YSeat belt motor RH fastened direction
signalSeat belt motor RH operation Battery voltage
Other than above 0
4GY/WSeat belt motor LH fastened direction
signalSeat belt motor LH operation Battery voltage
Other than above 0
5 B/Y Ground (Driver circuit) – 0
6L/YSeat belt motor LH release direction
signalSeat belt motor LH operation Battery voltage
Other than above 0
7 G/Y Seat belt indicator signalWhen driver side seat belt is fastened Battery voltage
When driver side seat belt is un-fastened 0
When driver side seat belt is fastened and
system malfunctionBattery
voltage
0
8 LG Seat belt buckle switch RHWhen seat belt is fastened 5
When seat belt is un-fastened 0
10 SB Seat belt buckle switch LHWhen seat belt is fastened Battery voltage
When seat belt is un-fastened 0
13 W/G Power source (IGN) Ignition switch ON or START Battery voltage
16 WBrake pedal stroke sensor output sig-
nal 1Brake pedal is fully released operation 1
Brake pedal is slightly depressed operation 4
18 RPower source (Brake pedal stroke sen-
sor)
–5
20 GBrake pedal stroke sensor output sig-
nal 2Brake pedal is fully released operation 4
Brake pedal is slightly depressed operation 1
21 B Ground (Brake pedal stroke sensor) – 0
22 P CAN-L – -
24 L CAN-H – -
25 – Ground (Shield wire) – 0
26 B/Y Ground (Control circuit) – 0

PRE-CRASH SEAT BELT
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Revision: 2006 January2006 M35/M45
6. Select diagnosis mode.
“SELF-DIAG RESULTS”, “DATA MONITOR”, “CAN DIAG SUP-
PORT MNTR“ and “ECU PART NUMBER” are available.
HOW TO READ SELF-DIAGNOSTIC RESULTS
SELF-DIAGNOSTIC RESULTS ITEM CHART
DATA MONITOR ITEM CHART
BCIA0031E
PHIA1176E
CONSULT-II display Item Malfunction is detected when...Reference
page
CAN COMM CIRCUIT [U1000] CAN communication Malfunction is detected in CAN communication. SB-16
SB MOTOR RH CIRC [B2451] Seat belt motor RH Circuit of seat belt motor (RH) is open or shorted.SB-27
SB MOTOR LH CIRC [B2452] Seat belt motor LH Circuit of seat belt motor (LH) is open or shorted.SB-25
BR STROKE SEN CIRC [B2453]Brake pedal stroke
sensorCircuit of brake pedal stroke sensor is open or shorted.SB-22
MOTOR PWR SUP CIRC [B2454]Motor power supply
circuitCircuit of motor power supply is open or shorted.SB-17
PSB C/U INT CIRCUIT [B2455] ECU circuit ECU circuit internal abnormality –
Monitor item [OPERATION or UNIT] Contents
SB SW RH SIG “ON/OFF” RH seat belt switch signal is displayed.
SB SW LH SIG “ON/OFF” LH seat belt switch signal is displayed.
VHCL SPEED SE “Km/h” Vehicle speed signal is displayed.
B PEDAL SIG1 “V” Brake pedal stroke sensor 1 signal voltage is displayed.
B PEDAL SIG 2 “V” Brake pedal stroke sensor 2 signal voltage is displayed.

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PRE-CRASH SEAT BELT
Revision: 2006 January2006 M35/M45
Preliminary CheckNHS00086
PRE-CRASH SEAT BELT OPERATION INSPECTION
WAR NING :
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 ChartNHS00087
Check CAN Communication System Inspection [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-7, "Precautions When Using CONSULT-II" .
No >> Inspection END.
Symptom Diagnosis procedureReference
page
All functions of pre-crash seat belt system does not oper-
ate.Ignition power supply circuit checkSB-17
Motor power supply and ground circuit checkSB-17
CAN communication circuit checkSB-16
Replace pre-crash seat belt control unit.SB-29
Driver side pre-crash seat belt system does not operate.Seat belt buckle switch (driver side) circuit checkSB-19Pre-crash seat belt motor LH checkSB-25
Replace pre-crash seat belt control unit.SB-29
Passenger side pre-crash seat belt system does not oper-
ate.Seat belt buckle switch (passenger side) circuit checkSB-21Pre-crash seat belt motor RH checkSB-27
Replace pre-crash seat belt control unit.SB-29
Pre-crash seat belt system does not operate during emer-
gency brake operation.CAN communication circuit checkSB-16Brake pedal stroke sensor circuit checkSB-22
Brake pedal stroke sensor shield wire circuit checkSB-28
Replace pre-crash seat belt control unit.SB-29
PHIA0772E

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PRE-CRASH SEAT BELT
Revision: 2006 January2006 M35/M45
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.
Brake Pedal Stroke Sensor Circuit Check [B2453]NHS0008D
1. INSPECTION WITH CONSULT-II
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 2When seat belt is unfastened Yes
When seat belt is fastened No
PHIA1131E
Te r m i n a l
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

PRE-CRASH SEAT BELT
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Revision: 2006 January2006 M35/M45
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 the 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
ConditionVoltage (V)
(Approx.) (+)
(–) Pre-crash seat
belt control unit
connectorTe r m i n a l
B14216
GroundBrake released

depressed1 4
20 4
1PHIA1134E

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PRE-CRASH SEAT BELT
Revision: 2006 January2006 M35/M45
3. CHECK BRAKE PEDAL STROKE SENSOR HARNESS
1. Turn the ignition switch OFF.
2. Disconnect pre-crash seat belt control unit connector and brake pedal stroke sensor connector.
3. Check continuity between pre-crash seat belt control unit har-
ness connector and brake pedal stroke sensor harness connec-
tor.
4. Check continuity between pre-crash seat belt control unit harness connector and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness between pre-crash seat belt control unit and brake pedal stroke sensor.
4. CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY
1. Connect pre-crash seat belt control unit connector.
2. Turn the ignition switch ON.
3. Check voltage between pre-crash seat belt control unit harness
connector and ground.
OK or NG
OK >> GO TO 5.
NG >> Replace pre-crash seat belt control unit.
AB
Continuity Pre-crash seat
belt control unit
connectorTe r m i n a lBrake pedal stroke
sensor connectorTerminal
B14216
E1251
Ye s 18 2
20 3
21 4
A
GroundContinuity
Pre-crash seat belt
control unit connectorTerminal
B14216
No 18
20
21
PHIA1135E
Terminal
Voltage (V)
(Approx.) (+)
(–) Pre-crash seat
belt control unit
connectorTerminal
B142 18 Ground 5
PHIA1136E

PRE-CRASH SEAT BELT
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Revision: 2006 January2006 M35/M45
5. CHECK BRAKE PEDAL STROKE SENSOR
Check continuity between brake pedal stroke sensor while perform-
ing brake operation.
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 >> Replace brake pedal stroke sensor.
Pre-Crash Seat Belt Motor LH Circuit Check [B2452]NHS0008E
1. CHECK LH SEAT BELT MOTOR CIRCUIT
With CONSULT-II
Select “SELF-DIAG RESULTS” of CONSULT-II, and then make sure
that “SB MOTOR LH CIRC” is displayed.
Without CONSULT-II
When CONSULT-II is not used, omit this inspection, and then GO TO 2.
Displayed B2452?
Ye s > > G O T O 2 .
No >> Pre-crash seat belt motor LH circuit is OK.
Brake pedal stroke
sensor connectorTerminal ConditionResistance
(K)
(Approx.)
E125 21
Brake released
depressed1.0 0.2
30.2
1.0
PHIA1137E
CONSULT-II display CONSULT-II display code
NO DTC –
SB MOTOR LH CIRC B2452
PHIA0768E

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PRE-CRASH SEAT BELT
Revision: 2006 January2006 M35/M45
3. CHECK SEAT BELT MOTOR
Check continuity between pre-crash seat belt motor RH.
OK or NG
OK >> Replace pre-crash seat belt control unit.
NG >> Replace pre-crash seat belt motor RH.
Brake Pedal Stroke Sensor Shield Wire Circuit CheckNHS0008G
1. CHECK PRE-CRASH SEAT BELT INPUT SIGNAL
With CONSULT-II
Select “B PEDAL SIG1 and 2” on DATA MONITOR screen, and then
make sure that the voltage does not change if brake pedal is not
operated.
NOTE:
Diagnosis should be performed with engine running, audio and air
conditioner operating.
Without CONSULT-II
1. Start engine.
2. Check voltage between pre-crash seat belt harness connector.
OK or NG
OK >> Brake pedal stroke sensor shield wire circuit is OK.
NG >> Check shield wire for damage. Repair or replace if necessary.
Pre-crash seat belt
motor RH connectorTerminal Continuity
B8 1 2 Yes
PHIA1139E
B PEDAL SIG1
Brake released :There is no change in the voltage
value, and it is almost constant
B PEDAL SIG2
Brake released :There is no change in the voltage
value, and it is almost constant.
Terminal
ConditionVoltage (V)
(Approx.) (+)
(–) Pre-crash seat
belt control unit
connectorTerminal
B14216
GroundPerformed with
engine running, audio
and air conditioner
operating and brake
pedal released.There is no
change in the
voltage value,
and it is almost
constant 20
PHIA0766E
PHIA1141E