2000 NISSAN PATROL Electronic Repair Manual

Seat Belt Pre-tensioner with Load Limiter
The seat belt pre-tensioner system with load limiter is installed
to both the driver's seat and the front passenger's seat. It oper-
ates simultaneously with the SRS air bag system in the event of
a frontal collision with an impact exceeding a specified level.
When a frontal collision with an impact exceeding a specified
level occurs, seat belt slack resulting from clothing or other fac-
tors is immediately taken up by the pre-tensioner. Vehicle pas-
sengers are securely restrained.
When passengers in a vehicle are thrown forward in a collision
and the restraining force of the seat belt exceeds a specified
level, the stopper-A pin will break, allowing the ring gear to
rotate. At this point, resistance force from the belt housing is
applied to the wire attached to the ring gear so that the wire
keeps a constant level of tension (resistance against further rota-
tion of the ring gear in the normal direction). As the ring gear
stopper-A rotates and reaches the stopper-B position, it will
cease its rotation, causing the seat belt webbing to stop extend-
ing. By the mechanism previously described, the load limiter
permits the specified extension of the seat belt and a relaxation
of the chest-area seat belt web tension while maintaining force.
SRS Component Parts Location
SRS501
SRS756
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
RS-1005

Maintenance Items
CAUTION:
Do not use electrical test equipment to check SRS circuit.
1. Check operation of ªAIR BAGº and ªSEAT BELTº warning
lamps (ªSEAT BELTº warning lamp can be used for check-
ing seat belt pre-tensioner on models except for Europe.).
After turning ignition key to ªONº position, both warning
lamps illuminate. The ªAIR BAGº warning lamp will go off
after about 7 seconds if no malfunction is detected. The
ªSEAT BELTº warning lamp will also go off after about 7
seconds after seat belt has been fastened and no malfunc-
tion is detected. (When seat belt has not been fastened, the
warning lamp continues to illuminate until seat belt is fas-
tened.)
If any of the following warning lamp conditions occur, imme-
diately check the air bag or seat belt pre-tensioner system.
Refer to RS-1032 for details.
+The ªAIR BAGº or ªSEAT BELTº warning lamp does not illu-
minate when the ignition switch is turned ªONº.
+The ªAIR BAGº or ªSEAT BELTº (with seat belt fastened)
warning lamp does not go off about 7 seconds after the igni-
tion switch is turned ªONº.
+The ªAIR BAGº or ªSEAT BELTº (with seat belt fastened)
warning lamp blinks after about 7 seconds after the ignition
switch is turned ªONº.
2. Visually check SRS components
(1) Diagnosis sensor unit
+Check diagnosis sensor unit and bracket for dents, cracks or
deformities.
+Check connectors for damage, and terminals for deformities.
(2) Air bag module and steering wheel
+Remove air bag module from steering wheel, instrument
panel or seat back. Check harness cover and connectors for
damage, terminals for deformities, and harness for binding.
+Install driver air bag module to steering wheel to check fit or
alignment with the wheel.
+Check steering wheel for excessive free play.
+Install passenger air bag module to instrument panel to
check fit or alignment with the instrument panel.
+Install side air bag module to seat back to check fit and
alignment with the seat.
(3) Spiral cable
+Check spiral cable for dents, cracks, or deformities.
+Check connectors and protective tape for damage.
+Check steering wheel for noise, binding or heavy operation.
(4) Main harness and body harness
+Check connectors for poor connections, damage, and termi-
nals for deformities.
+Check harnesses for binding, chafing or cut.
(5) Seat belt pre-tensioner
+Check harness cover and connectors for damage, terminals
for deformities, and harness for binding.
+Check belts for damage and anchors for loose mounting.
+Check retractor for smooth operation.
SRS222-B
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
RS-1006

+Perform self-diagnosis for seat belt pre-tensioner using seat
belt warning lamp or CONSULT-II. Refer to ªSelf-diagnosisº
for details.
(6) Satellite sensor
+Check satellite sensor (including bracket portion) for dents,
cracks or deformities.
+Check connectors for damage, and terminals for deformities.
CAUTION:
Replace previously used special bolts, ground bolt and nuts
coated with bonding agent.
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Maintenance Items (Cont'd)
RS-1007

Removal and Installation Ð Diagnosis
Sensor Unit, Seat Belt Pre-tensioner with
Load Limiter and Satellite Sensor
CAUTION:
+Before servicing SRS, turn the ignition switch off, disconnect both battery cables and wait at least
3 minutes.
+Do not use old bolts and nuts coated with bonding agent after removal; replace with new ones.
+Check diagnosis sensor unit, seat belt pre-tensioner with load limiter and satellite sensor for
proper installation.
+Check diagnosis sensor unit and satellite sensor to ensure they are free of deformities, dents,
cracks or rust. If they show any visible signs of damage, replace them with new ones.
+Check diagnosis sensor unit brackets to ensure they are free of deformities and rust.
+After replacement of diagnosis sensor unit, seat belt pre-tensioner and satellite sensor, check
SRS function and perform self-diagnosis for SRS. Refer to ªSelf-diagnosisº for details. (RS-1032)
+Do not attempt to disassemble diagnosis sensor unit, seat belt pre-tensioner with load limiter and
satellite sensor.
+Replace diagnosis sensor unit, seat belt pre-tensioner and satellite sensor if it has been dropped
or sustained an impact.
+Do not expose seat belt pre-tensioner to temperatures exceeding 80ÉC (176ÉF).
REMOVAL OF DIAGNOSIS SENSOR UNIT
1. Disconnect driver, passenger and side air bag module con-
nectors. Also, disconnect seat belt pre-tensioner connector.
2. Remove console finisher, console box assembly and instru-
ment panel stay cover. Refer to ªINSTRUMENT PANELº in
BT section.
3. Disconnect diagnosis sensor unit connector.
4. Remove bolt and also remove special bolts using the
TAMPER RESISTANT TORX (Size T50), from diagnosis
sensor unit.
Then remove the diagnosis sensor unit.
NOTE:
+To install, reverse the removal procedure sequence.
+After replacement, perform self-diagnosis for SRS. Refer
to ªSelf-diagnosisº for details (RS-1032).
CAUTION:
+Do not use old special bolts coated with bonding agent;
replace with new coated special bolts.
SRS757
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
RS-1008

REMOVAL OF SATELLITE SENSOR
1. Remove seat belt pre-tensioner with load limiter or seat belt
retractor. Refer to ªREMOVAL OF SEAT BELT PRE-TEN-
SIONER WITH LOAD LIMITERº or ªFront seat beltº in RS
section of Service Manual (Pub. No. SM7E-2Y61G0 or
SM7E-2Y61G1) for details.
2. Disconnect satellite sensor connector.
3. Remove bolt and nuts coated with bonding agent from sat-
ellite sensor unit.
Then remove the satellite sensor.
NOTE:
+To install, reverse the removal procedure sequence.
CAUTION:
+Do not use old nuts coated with bonding agent after
removal; replace with new coated nuts.
Removal Ð Driver Air Bag Module and Spiral
Cable
SRS758
SRS759-A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Removal and Installation Ð Diagnosis
Sensor Unit, Seat Belt Pre-tensioner with
Load Limiter and Satellite Sensor (Cont'd)
RS-1009

CAUTION:
+Before servicing SRS, turn the ignition switch OFF, dis-
connect both battery cables and wait at least 3 minutes.
+Always work from the side of air bag module.
1. Remove lower lid from steering wheel, and disconnect air
bag module connector.
2. Remove side lid, ASCD steering switch and audio steering
switch (only on models for the Middle East). Using the
TAMPER RESISTANT TORX (Size T50), remove left and
right special bolts. Air bag module can then be removed.
CAUTION:
+Always place air bag module with pad side facing
upward.
+Do not attempt to disassemble air bag module.
+The special bolts are coated with bonding agent. Do not
use old bolts after removal; replace with new ones.
+Do not insert any foreign objects (screwdriver, etc.) into
air bag module connector.
+Replace air bag module if it has been dropped or sus-
tained an impact.
+Do not expose the air bag module to temperatures
exceeding 90ÉC (194ÉF).
+Do not allow oil, grease or water to come in contact with
the air bag module.
3. Set steering wheel in the neutral position.
4. Disconnect horn connector and remove nuts.
5. Remove dynamic damper. Then using steering wheel puller,
remove steering wheel. Be careful not to over-tighten puller
bolt on steering wheel.
CAUTION:
+Do not tap or bump the steering wheel.
6. Remove steering column cover.
SBF811E
SBF812E
SRS161
SBF814E
SBF239F
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Removal Ð Driver Air Bag Module and
Spiral Cable (Cont'd)
RS-1010

7. Remove the four screws. Then unlock the spiral cable con-
nector and disconnect connector. The spiral cable can then
be removed.
CAUTION:
+Do not attempt to disassemble spiral cable.
+Do not apply lubricant to the spiral cable.
Installation Ð Driver Air Bag Module and
Spiral Cable
1. Set the front wheels in the straight-ahead position.
2. Connect spiral cable connector. Then, lock the connector
and tighten with screws. Install steering column cover.
3. Make sure that the spiral cable is in the neutral position.
The neutral position is detected by turning left about 2.5
revolutions from the right end position. Align the two marks
(
,
m).
CAUTION:
+The spiral cable may snap due to steering operation if
the cable is installed in an improper position.
Also, with the steering linkage disconnected, the cable
may snap by turning the steering wheel beyond the lim-
ited number of turns.
The spiral cable can be turned up to about 2.5 turns from
the neutral position to both the right and left.
4. Connect spiral cable connector and tighten with screws.
Install steering column cover.
5. Install steering wheel, setting spiral cable pin guide, and pull
spiral cable through.
6. Connect horn connector and engage spiral cable with pawls
in steering wheel. Move air bag module connector away from
steering wheel lower lid opening.
7. Tighten nut.
:29-39Nzm (3.0 - 4.0 kg-m, 22 - 29 ft-lb)
8. Install dynamic damper.
SRS384
SRS384
SRS165
SRS231
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Removal Ð Driver Air Bag Module and
Spiral Cable (Cont'd)
RS-1011

9. Position air bag module and tighten with new special bolts.
+Always service the air bag module from the side.
10. Connect air bag module connector.
11. Install steering switches and lids.
12. Perform self-diagnosis to ensure entire SRS operates prop-
erly. (Use CONSULT-II or warning lamp check.) Refer to
RS-1032.
Before performing self-diagnosis, connect both battery
cables.
13. Turn steering wheel to the left end and then to the right end
fully to make sure that spiral cable is set in the neutral posi-
tion.
If air bag warning lamp blinks or stays ON (at the User
mode), it shows the spiral cable may be snapped due to its
improper position. Perform self-diagnosis again (use CON-
SULT-II or warning lamp). If a malfunction is detected,
replace the spiral cable with a new one.
14. Perform self-diagnosis again to check that no malfunction is
detected.
Removal Ð Side Air Bag Module
CAUTION:
+Before servicing SRS, turn the ignition switch OFF, dis-
connect both battery cables and wait at least 3 minutes.
+Always work from the rear of the air bag module.
1. Remove seatback board.
+When using a clip removal tool to remove the seatback
board, take care not to damage the air bag harness.
2. Disconnect side air bag module connector.
3. Remove the nuts securing the inner cloth with seatback
frame. Then pull up the inner cloth.
SBF812EG
SRS760
SRS761-A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Installation Ð Driver Air Bag Module and
Spiral Cable (Cont'd)
RS-1012