2004 TOYOTA 4RUNNER sensor

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The driver and front passenger seat
belt pretensioners are designed to be
activated in response to a severe fron-
tal impact or a vehicle rollover.
When the sensor detects a severe frontal
impact or a vehicle rollover, the front seat
belts are quickly drawn back by the re-
tractors so that the belts snugly restrain
the occupants.
The seat belt pretensioners are activated
even with no passenger in the front seat.
The seat belt pretensioners and SRS air-
bags may not operate together in all colli-
sions.Ty p e A
Ty p e B
The seat belt pretensioners will not oper-
ate in a vehicle rollover if the “RSCA
OFF” indicator light is on. For details, see
“Roll sensing of curtain shield airbags off
switch” on page 87 in this Section.
—Seat belt pretensioners

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The seat belt pretensioner system con-
sists mainly of the following components
and their locations are shown in the il-
lustration.
1. Front airbag sensors
2. SRS warning light
3. Seat belt pretensioner assemblies
4. Airbag sensor assembly
The seat belt pretensioners are controlled
by the airbag sensor assembly. The airbag
sensor assembly consists of a safing sen-
sor and airbag sensor. When the seat belt pretensioners are acti-
vated, 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 as-
semblies, airbag sensor or sur-
rounding area or wiring. Failure to
follow these instructions may pre-
vent the seat belt pretensioners
from activating correctly, cause sud-
den operation of the system or dis-
able the system, which could result
in death or serious injury. Consult
your Toyota dealer about any repair
and modification.
Do not modify or change the sus-
pension system. Such changes may
cause the curtain shield airbags to
inflate accidentally, which could re-
sult in death or serious injury. Con-
sult your Toyota dealer about any
repair and modification.
Do not use tires or wheels other
than the manufacture’s recom-
mended size. Such a use may cause
the curtain shield airbags and seat
belt pretensioners to inflate acci-
dentally, which could result in death
or serious injury. For details, see
“Checking and replacing tires” on
page 370 in Section 72.
Do not place luggage heavier than
specified on the roof luggage carri-
er. Such luggage may cause the
curtain shield airbags and seat belt
pretensioners to inflate accidentally,
which could result in death or seri-
ous injury. For details, see “Roof
luggage carrier” on page 266 in
Section 110.

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NOTICE
Do not perform any of the following
changes without consulting your
Toyota 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 compact
disc player
 Repairs on or near the front seat
belt retractor assemblies
 Modification of the front end struc-
ture
 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 con-
sole
This indicator comes on when the igni-
tion key 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 sen-
sors, side and curtain shield airbag sen-
sors, curtain shield airbag sensors, driv-
er ’s seat position sensor, driver ’s seat belt
buckle switch, seat belt pretensioner as-
semblies, inflators, warning light, “RSCA
OFF” indicator light, interconnecting wiring
and power sources. (For details, see “Ser-
vice reminder indicators and warning buzz-
ers” on page 137 in Section 1− 6.)If any of the following conditions occurs,
this indicates a malfunction of the airbags
or seat belt pretensioners. Contact your
Toyota dealer as soon as possible.
When the ignition key is turned to the
“ON” position, the light does not come
on, remains on or flashes.
The light comes on or starts flashing
while driving.
If any seat belt does not retract or can
not 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.

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Collision from the rear
Collision from the side Vehicle rollover
The SRS front airbags are generally not
designed to inflate if the vehicle is in-
volved in a side or rear collision, if it
rolls over, or if it is involved in a low
speed frontal collision. But, when ever a
collision of any type causes sufficient
forward deceleration of the vehicle, de-
ployment of the SRS front airbags may
occur.
Hitting a curb, edge
of pavement or
hard surface Falling into or
jumping over
a deep hole
Landing hard or vehicle falling
The SRS front airbags may also deploy
if a serious impact occurs to the under-
side of your vehicle. Some examples
are shown in the illustration.The SRS front airbag system consists
mainly of the following components, and
their locations are shown in the illustra-
tion. 1. Front airbag sensors
2. SRS warning light
3. Airbag module for front passenger (airbag and inflator)
4. Driver ’s seat belt buckle switch
5. Driver ’s seat position sensor
6. Airbag sensor assembly
7. Airbag module for driver (airbag and inflator)
The airbag sensor assembly consists of a
safing sensor and airbag sensor.

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The front airbag sensors constantly moni-
tor the forward deceleration of the vehicle.
If an impact results in a forward decelera-
tion beyond the designed threshold level,
the system triggers the airbag inflators. At
this time a chemical reaction in the infla-
tors very quickly fills the air bags 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 imme-
diately. Deployment of the airbags happens in a
fraction of a second, so the airbags must
inflate with considerable force. While the
system is desi
gned to reduce serious inju-
ries, 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 seri-
ous 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 ve-
hicle.
Parts of the airbag module (steering wheel
hub, 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 inflat-
ing airbag.CAUTION
The driver or front passenger who is
too close to the steering wheel or
dashboard during airbag deployment
can be killed or seriously injured.
Toyota strongly recommends that:
The driver sit as far back as pos-
sible from the steering wheel while
still maintaining control of the ve-
hicle.
The front passenger sit as far back
as possible from the dashboard.
All vehicle occupants be properly
restrained using the available seat
belts.
For instructions and precautions con-
cerning the seating position, see
“—Front seat precautions” on page
40 in this Section.

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Do not put anything or any part of
your baby on or in front of the
dashboard or steering wheel pad
that houses the front airbag sys-
tem. They might restrict inflation or
cause death or serious injury as
they are projected rearward by the
force of the deploying airbags. Like-
wise, the driver and front passenger
should not hold objects in their
arms or on their knees.
Do not modify or remove any wir-
ing. Do not modify, remove, strike
or open any components such as
the steering wheel pad, steering
wheel, column cover, dashboard
near the front passenger airbag,
front passenger airbag cover, front
passenger airbag or airbag sensor
assembly. Doing so may prevent the
front airbag system from activating
correctly, cause sudden activation
of the system or disable the sys-
tem, which could result in death or
serious injury.
Failure to follow these instructions
can result in death or serious injury.
Consult your Toyota dealer about any
repair and modification.NOTICE
Do not perform any of the following
changes without consulting your
Toyota dealer. Such changes can in-
terfere with proper operation of the
SRS front airbag system in some
cases.
 Installation of electronic devices
such as a mobile twoway radio,
cassette tape player or compact
disc player
 Modification of the suspension sys-
tem
 Modification of the front end struc-
ture
 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, con-
sole, steering column, steering
wheel or dashboard near the front
passenger airbag

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2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
This indicator comes on when the igni-
tion key is turned to the “ON” position.
It goes off after about 6 seconds. This
means the SRS front airbags are oper-
ating properly.
This warning light system monitors the
airbag sensor assembly, front airbag sen-
sors, side and curtain shield airbag sen-
sors, curtain shield airbag sensors, driv-
er ’s seat position sensor, driver ’s seat belt
buckle switch, seat belt pretensioner as-
semblies, inflators, warning light, “RSCA
OFF” indicator light, interconnecting wiring
and power sources. (For details, see “Ser-
vice reminder indicators and warning buzz-
ers” on page 137 in Section 1 −6.) If any of the following conditions occurs,
this indicates a malfunction of the airbags
or seat belt pretensioners. Contact your
Toyota dealer as soon as possible.
When the ignition key is turned to the
“ON” position, the light does not come
on, remains on or flashes.
The light comes on or starts flashing
while driving.
In the following cases, contact your Toyota
dealer as soon as possible:
The SRS front airbags have been in-
flated.
The front of the vehicle (shaded in the
illustration) was involved in an accident
that was not severe enough to cause
the SRS front airbags to inflate.
The pad section of the steering wheel
or dashboard (shaded in the illustra-
tion) is scratched, cracked, or other-
wise damaged.

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2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
The SRS side airbag and curtain shield
airbag system consists mainly of the fol-
lowing components, and their locations are
shown in the illustration.
1. SRS warning light
2. Curtain shield airbag modules (airbag and inflator)
3. Side airbag modules (airbag and inflator)
4. Curtain shield airbag sensors
5. Side and curtain shield airbag sensors
6. Airbag sensor assembly The SRS side airbag and curtain shield
airbag system is controlled by the airbag
sensor assembly. The airbag sensor as-
sembly consists of a safing sensor and
airbag sensor.
In a severe side impact, the side and
curtain shield airbag sensor and/or the
curtain shield airbag sensor trigger(s) the
side airbag inflators and/or the curtain
shield airbag inflators. At this time a
chemical reaction in the inflators quickly
fills the airbags with non
−toxic gas to help
restrain the lateral motion of the occu-
pants.
In a vehicle rollover, the airbag sensor
assembly triggers the curtain shield airbag
inflator. At this time, a chemical reaction
in the inflators quickly fills the airbags
with non −toxic gas to help restrain the
lateral motion of the occupants. When the airbags inflate, they produce a
fairly 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 imme-
diately.
Deployment of the airbags happens in a
fraction of a second, so the airbags must
inflate with considerable force. While the
system is desi gned to reduce serious inju-
ries, it may also cause minor burns or
abrasions and swelling.
Front seats as well as parts of the front
and rear pillars, front, center and rear
garnish and roof interior may be hot for
several minutes, but the airbags them-
selves will not be hot. The airbags are
designed to inflate only once.