2008 TOYOTA 4RUNNER sensor

iv
In order to be effective, the SRS airbags must deploy with
tremendous speed. The rapid deployment of the SRS air-
bags makes the SRS airbags themselves potential sources
of death or serious injury if an occupant is too close to an
airbag, or if an object or some part of his or her body has
been placed between the occupant and the airbag at the
time of deployment. This is just one example of how the
instructions in Section 1−3 of this Owner ’s Manual will help
ensure proper use of the occupant restraint systems, and
increase the safety they can provide to you and your fami-
ly in the event of an accident.
Toyota recommends you to read the provisions in Section
1−3 carefully and refer to them as needed during your time
of ownership of this vehicle.Event data recorder
Your vehicle has computers that monitor and control cer-
tain aspects of your vehicle. These computers assist in
driving and maintaining optimal vehicle performance. Be-
sides storing data useful for troubleshooting, there is a
system to record data in a crash or a near car crash
event. This is called an Event Data Recorder (EDR).
The SRS airbag sensor assembly contains the EDR. In a
crash or a near car crash event, this device may record
some or all of the following information:Engine speed
 Whether the brake pedal was applied or not
 Vehicle speed
 To what extent the accelerator pedal was depressed
 Position of the transmission selector lever
 Whether the driver and front passenger wore the
seat belts or not
 Driver’s seat position
 Front passenger ’s occupant classification

71
CY13018
The driver and front passenger seat
belt pretensioners are designed to be
activated in response to a severe fron-
tal impact. The pretensioners are also
activated during 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 pretensioner will not activate
if no passenger is detected in the front
passenger seat by the front passenger
occupant classification system. However,
the front passenger ’s seat belt
pretensioner may activate if luggage is put
on the seat, or the seat belt is buckled up
regardless of the presence of an occupant
in the seat. (As for the front passenger
occupant classification system, see
Front passenger occupant classification
system" on page 91 in this Section.)
The seat belt pretensioners and SRS air-
bags may not operate together in all colli-
sions.
CY13294
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 95 in this Section.
Seat belt pretensioners

72
CY13293
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. Front passenger occupant classification indicator light
4. Front passenger occupant classification system (ECU and sensors)
5. Seat belt pretensioner assemblies
6. Front passenger ’s seat belt buckle switch
7. 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 443 in Section 7−2.
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 334 in
Section 1−10.

73
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 two−way 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
CY13295
This indicator comes on when the
engine switch is turned to the ON"
position. It goes off after about 6 se-
conds. This means the seat belt preten-
sioners 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, front passenger occupant
classification system and indicator light,
front passenger ’s seat belt buckle switch,
seat belt pretensioner assemblies, inflat-
ors, RSCA OFF" indicator light, intercon-
necting wiring and power sources. (For
details, see Service reminder indicators
and warning buzzers" on page 149 in Sec-
tion 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.
The light does not come on when the
engine switch is turned to the ON"
position or remains on for more than
6 seconds 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.

74
The SRS warning light will come on and
front passenger occupant classification in-
dicator light will indicate OFF" if there is
a malfunction in the front passenger occu-
pant classification system.
CY13064
In the following cases, contact your Toyota
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.
Either seat belt pretensioner assembly
or surrounding area is scratched,
cracked, or otherwise damaged.
CY13019
The SRS (Supplemental Restraint Sys-
tem) front airbags are designed to pro-
vide further protection for the driver
and front passenger in addition to the
primary safety protection provided by
the seat belts.
Your vehicle is equipped with ADVANCED
AIRBAGS" designed based on US motor
vehicle safety standards (FMVSS208). The
airbag system controls airbag deployment
power for the driver and front passenger.
The driver airbag system consists of the
driver seat’s position sensor etc. The front
passenger ’s airbag system consists of the
front passenger occupant classification
sensor etc.
SRS airbags
SRS driver airbag and front
passenger airbag

77
CY13280
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. Front passenger occupant classification indicator light
4. Airbag module for front passenger (airbag and inflator)
5. Front passenger occupant classification system (ECU and sensors)
6. Front passenger ’s seat belt buckle switch
7. Driver ’s seat belt buckle switch 8. Driver ’s seat position sensor
9. Airbag sensor assembly
10. Airbag module for driver (airbag and inflator)
The airbag sensor assembly consists of a
safing sensor and airbag sensor.
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.

79
CY13114
Do not put anything or any part of
your body 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 or airbag
sensor assembly. Doing so may pre-
vent the front airbag system from
activating correctly, cause sudden
activation of the system or disable
the system, 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.
If you wish to modify your vehicle for
a person with physical disability, con-
sult your Toyota dealer. It may dan-
gerously interfere with the SRS front
airbags operation.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 two−way 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

80
CY13295
This indicator comes on when the en-
gine switch is turned to the ON" posi-
tion. It goes off after about 6 seconds.
This means the SRS front airbags 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, front passenger occupant
classification system and indicator light,
front passenger ’s seat belt buckle switch,
seat belt pretensioner assemblies, inflat-
ors, RSCA OFF" indicator light, intercon-
necting wiring and power sources. (For
details, see Service reminder indicators
and warning buzzers" on page 149 in Sec-
tion 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.
The light does not come on when the
engine switch is turned to the ON"
position or remains on for more than
6 seconds or flashes.
The light comes on or starts flashing
while driving.
The SRS warning light will come on and
front passenger occupant classification in-
dicator light will indicate OFF" if there is
a malfunction in the front passenger occu-
pant classification system.
CY13065
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 acci dent
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.