2005 LEXUS LS430 belt

OCCUPANT RESTRAINT SYSTEMS
176
Seat belt pretensioners
16L645
Both front seats and the two outboard rear seats are
equipped with seat belt pretensioners and are designed to
be activated in response to a severe frontal impact.
When the sensor detects a severe frontal impact, the seat belts
are quickly drawn back by the retractor so that the belts snugly
restrain the seat occupants.
The front passenger seat belt pretensioner will not activate if
there is no passenger sitting in the front passenger seat.
However, the front passenger seat belt pretensioner may
activate if luggage is put in the seat, or the seat belt is buckled
up regardless of the presence of the occupant in the seat.
The outboard rear seat belt pretensioners are activated even
with no passengers in the outboard rear seats.
The seat belt pretensioners and SRS airbags may not operate
together in all collisions.
16L649a
 1 Front airbag sensors
2Occupant detection sensor
3Front passenger’s seat belt buckle switch
4Front seat belt pretensioner assembly
5SRS warning light
6Rear seat belt pretensioner assembly
7Airbag sensor assembly
The seat belt pretensioner system consists mainly of the
above components, and their locations are shown in the
illustration.
The seat belt pretensioners are controlled by the airbag sensor
assembly. The airbag sensor assembly consists of a safing
sensor and airbag sensor.

OCCUPANT RESTRAINT SYSTEMS
177
When the seat belt pretensioners are activated, an operating
noise
may be heard and a small amount of non −toxic gas may
be released. This does not indicate that a fire is occurring. This
gas is normally harmless.
Once the seat belt pretensioners have been activated, the seat
belt retractors remain locked.
CAUTION
Do not modify, remove, strike or open the seat belt
pretensioner assemblies, airbag sensor or surrounding
area or wiring. Failure to follow these instructions may
prevent the seat belt pretensioners from activating
correctly, cause sudden operation of the system or
disable the system, which could result in death or
serious injury. Consult your Lexus dealer about any
repair and modification.
NOTICE
Do not perform any of the following changes without
consulting your Lexus dealer. Such changes can
interfere with proper operation of the seat belt
pretensioners in some cases.
 Installation of electronic devices such as a mobile
twoway radio, cassette tape player or CD player.
 Repairs on or near the seat belt retractor assemblies.
 Modification of the suspension system.
 Modification of the front end structure.
 Attachment of a grille guard (bull bar, kangaroo bar,
etc.), snowplow, winches or any other equipment to
the front end.
 Repairs made on or near the front fenders, front end
structure or console.

OCCUPANT RESTRAINT SYSTEMS
178
16L330b
This indicator comes on when the ignition switch is turned
to the “ON” position. It goes off after about 6 seconds.
This means the seat belt pretensioners are operating
properly.
This warning light system monitors the airbag sensor
assembly, front airbag sensors, side and curtain shield airbag
sensor assemblies, curtain shield airbag sensor assemblies,
driver’s seat position sensor, driver’s seat belt buckle switch,
occupant detection sensor, front passenger’s seat belt buckle
switch, seat belt pretensioner assemblies, inflators, warning
light, interconnecting wiring and power sources. (For details,
see “Service reminder indicators and warning buzzers” on
page 82.) If any of the following conditions occurs, this indicates a
malfunction of the airbags or seat belt pretensioners. Contact
your Lexus dealer as soon as possible.

When the ignition switch is turned to the “ON” position, the
light does not come on or remains on for more than 6
seconds.
 The light comes on while driving.
 If any seat belt does not retract or cannot be pulled out due
to a malfunction or activation of the relevant seat belt
pretensioner.
 The seat belt pretensioner assembly or surrounding area
has been damaged.

OCCUPANT RESTRAINT SYSTEMS
179
16L650
In the following cases, contact your Lexus dealer as soon as
possible.
The front of the vehicle (shaded in the illustration) was
involved in an accident that was not severe enough to cause
the seat belt pretensioners to operate.
 The seat belt pretensioner assembly or surrounding area is
scratched, cracked, or otherwise damaged.
SRS DRIVER AIRBAGS AND FRONT
PASSENGER AIRBAGS
16L336a
 1Driver airbag 2Front passenger airbag
3Front passenger knee airbag 4
Driver knee airbag
The SRS (Supplemental Restraint System) front airbags
are designed to provide further protection for the driver
and front passenger in addition to the primary safety
protection provided by the seat belts.
In response to a severe frontal impact, the SRS front airbags
work together with the seat be lts to help reduce injury by
inflating. The SRS front airbags help reduce injuries mainly to
the driver’s or front passenger’s head, chest or knees caused
by hitting the vehicle interior.

OCCUPANT RESTRAINT SYSTEMS
180The SRS front passenger airbag will not activate if there is no
passenger sitting in the front passenger seat. However, the
front
passenger airbag may deploy if luggage is put in the seat,
or the seat belt is buckled up, regardless of the presence of an
occupant in the seat.
Always wear your seat belt properly.
CAUTION
 The SRS front airbag system is designed only as a
supplement to the primary protection of the driver
and front passenger seat belt systems. The driver
and front passenger can be killed or seriously injured
by the inflating airbags if they do not wear the
available seat belts properly . During sudden braking
just before a collision, an unrestrained driver or front
passenger can move forward into direct contact with
or close proximity to the airbag which may then
deploy during the collision. To ensure maximum
protection in an accident, the driver and all
passengers in the vehicle must wear their seat belts
properly. Wearing a seat belt properly during an
accident reduces the chances of death or serious
injury or being thrown out of the vehicle. For
instructions and precautions concerning the seat
belt system, see “Seat belts” on page 168.

OCCUPANT RESTRAINT SYSTEMS
181
Improperly seated and/or restrained infants and
children can be killed or seriously injured by the
deploying airbags. An infant or child who is too small
to use a seat belt should be properly secured using
a child restraint system. Lexus strongly
recommends that all infants and children be placed
in the rear seat of the vehicle and properly restrained.
The rear seat is the safest for infants and children.
For instructions concerning the installation of a child
restraint system, see “Child restraint” on page 199 .The SRS front airbags are designed to deploy in severe
(usually frontal) collisions where the magnitude and
duration of the forward deceleration of the vehicle
exceeds the designed threshold level.
The SRS front airbags will deploy if the severity of the impact
is above the designed threshold level, comparable to an
approximate 25 km/h (15 mph) collision when the vehicle has
the impact straight into a fixed barrier that does not move or
deform.
However, this threshold velocity will be considerably higher if
the vehicle strikes an object, such as a parked vehicle or sign
pole, which can move or deform on impact, or if the vehicle is
involved in an underride collision (e.g. a collision in which the
front of the vehicle “underrides”, or goes under, the bed of a
truck, etc.).
It is possible that in some collisions where the forward
deceleration of the vehicle is very close to the designed
threshold level, the SRS front airbags and the seat belt
pretensioners may not activate together.
Always wear your seat belts properly.

OCCUPANT RESTRAINT SYSTEMS
183
16L653a
 1Occupant detection sensor
2Airbag module for front passenger
(airbag and inflator)
3 Knee airbag module for front passenger
(airbag and inflator)
4 Front passenger’s seat belt buckle switch
5SRS warning light
6Airbag module for driver (airbag and inflator)
7Knee airbag module for driver (airbag and inflator)
8Driver’s seat belt buckle switch
9Driver’s seat position sensor
10Airbag sensor assembly
11Front airbag sensors
The SRS front airbag system consists mainly of the above
components, and their locations are shown in the illustration.
The airbag sensor assembly consists of a safing sensor and
airbag sensors. The front airbag sensors constantly monitor the forward
deceleration of the vehicle. If an impact results in a forward
deceleration beyond the designed threshold level, the system
triggers
the airbag inflators. At this time a chemical reaction in
the inflators very quickly fills the airbags with non−toxic gas to
help restrain the forward motion of the occupants. The front
airbags then quickly deflate, so that there is no obstruction of
the driver’s vision should it be necessary to continue driving.
When the airbags inflate, they produce a loud noise and
release some smoke and residue along with non −toxic gas.
This does not indicate a fire. This smoke may remain inside
the vehicle for some time, and may cause some minor irritation
to the eyes, skin or breathing. Be sure to wash off any residue
as soon as possible to prevent any potential skin irritation with
soap and water. If you can safely exit from the vehicle, you
should do so immediately.

OCCUPANT RESTRAINT SYSTEMS
184Deployment of the
airbags happens in a fraction of a second,
so the airbags must inflate with considerable force. While the
system is designed to reduce serious injuries, primarily to the
head and chest, it may also cause other, less severe injuries
to the face, chest, arms and hands. These are usually in the
nature of minor burns or abrasions and swelling, but the force
of a deploying airbag can cause more serious injuries,
especially if an occupant’s hands, arms, chest or head is in
close proximity to the airbag module at the time of deployment.
This is why it is important for the occupant to; avoid placing any
object or part of the body between the occupant and the airbag
module; sit straight and well back into the seat; wear the
available seat belt properly; and sit as far as possible from the
airbag module, while still maintaining control of the vehicle.
Parts of the airbag module (steering wheel hub, lower portion
of instrument panel, airbag cover and inflator) may be hot for
several minutes after deployment, so do not touch! The
airbags inflate only once. The windshield may be damaged by
absorbing some of the force of the inflating airbag.
CAUTION
The driver or front passenger who is too close to the
steering wheel, lower portion of instrument panel or
dashboard during airbag deployment can be killed or
seriously injured. Lexus strongly recommends that:
 The driver sit as far back as possible from the
steering wheel while still maintaining control of the
vehicle.
 The front passenger sit as far back as possible from
the dashboard.
 All vehicle occupants be properly restrained using
the available seat belts.
 If the seat belt extender has been connected to the
driver’s seat belt buckle but the seat belt extender
has not also been fastened to the latch plate of the
driver’s seat belt, the SRS driver’s airbag system will
judge that the driver is wearing the seat belt even
though the seat belt has not been connected. In this
case, the driver’s airbag may not activate correctly,
causing death or serious injury in the event of a colli-
sion. Be sure to wear the seat belt with the seat belt
extender. Otherwise, there will also not be any effec-
tive protection in a sudden stop or a collision pro-
vided by the seat belt.
For instructions and precautions concerning the
seating position, see “Front seat precautions” on page
154.