1999 TOYOTA 4RUNNER sensor

4RUNNER ()45
To connect the extender to the seat
belt, insert the tab into the seat belt
buckle so that the ºPRESSº signs on
the buckle- release buttons of the ex-
tender and the seat belt are both facing
outward as shown.
You will hear a click when the tab locks
into the buckle.
When releasing the seat belt, press on
the buckle- release button on the extender,
not on the seat belt. This helps prevent
damage to the vehicle interior and extend-
er itself.
When not in use, remove the extender
and store in the vehicle for future use.
CAUTION
After inserting the tab, make sure
the tab and buckle are locked and
that the seat belt extender is not
twisted.
Do not insert coins, clips, etc. in
the buckle as this may prevent you
from properly latching the tab and
buckle.
If the seat belt does not function
normally, immediately contact your
Toyota dealer. Do not use the seat
until the seat belt is fixed. It cannot
protect an adult occupant or your
child from injury.
ÐFront seat belt pretensioners
The driver and front passenger 's seat
belt pretensioners are designed to be
activated in response to a severe fron-
tal impact.
When the airbag sensor detects the shock
of a severe frontal impact, the front seat
belt is quickly drawn back in by the re-
tractor so that the belt snugly restrains
the front seat occupants.
The seat belt pretensioners are activated
even with no passenger in the front seat.

4RUNNER ()
46
This indicator comes on when the igni-
tion key is turned to the ºACCº or
ºONº position. It goes off after about
6 seconds. This means the front seat
belt pretensioners are operating proper-
ly.
This warning light system monitors the
airbag sensor assembly, front airbag sen-
sors, seat belt pretensioner assemblies,
warning light, interconnecting wiring and
power sources. (For details, see ºService
reminder indicators and warning buzzersº
in Chapter 1- 5.)The seat belt pretensioner system mainly
consists of the following components and
their locations are shown in the illustra-
tion. 1. Front airbag sensors
2. SRS airbag warning light
3. Seat belt pretensioner assemblies
4. Airbag sensor assembly
The seat belt pretensioner is controlled by
the airbag sensor assembly. The airbag
sensor assembly consists of a safing sen-
sor and airbag sensor. When a seat belt pretensioner is acti-
vated, an operating noise may be heard
and a small amount of smoke- like gas
may be released. This gas is harmless
and does not indicate that a fire is occur-
ring.
Once the seat belt pretensioner has been
activated, the seat belt retractor remains
locked.
CAUTION
Do not modify, remove, strike or open
the front seat belt pretensioner as-
semblies, airbag sensor or surround-
ing area or wiring. Doing any of
these may cause sudden operation of
the front seat belt pretensioners or
disable the system, which could re-
sult in serious injury.
Failure to follow these instructions
can result in serious injuries.

4RUNNER ()
48
The SRS (Supplemental Restraint Sys-
tem) airbags are designed to provide
further protection for the driver and
front passenger when added to the pri-
mary protection provided by the seat
belts.
In response to a severe frontal impact,
the SRS airbags work together with the
seat belts to help prevent or reduce injury
by inflating, in order to decrease the likeli-
hood of the driver 's or front passenger 's
head or chest directly hitting the steering
wheel or dashboard. The passenger airbag
is activated even with no passenger in the
front seat.
Be sure to wear your seat belt.
CAUTION
A driver or front passenger 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.
This indicator comes on when the igni-
tion key is turned to the ºACCº or
ºONº position. It goes off after about
6 seconds. This means the SRS airbags
are operating properly.
This warning light system monitors the
airbag sensor assembly, front airbag sen-
sors, inflators, warning light, interconnect-
ing wiring and power sources. (For details,
see ºService reminder indicators and
warning buzzersº in Chapter 1- 5.)
SRS driver and front
passenger airbags

4RUNNER ()49
The SRS airbag system is designed to
activate in response to a severe frontal
impact within the shaded area between
the arrows in the illustration.
There may be the case that the SRS air-
bags will not activate with such an impact
in which the occupant wearing the seat
belt correctly would not get serious injury.
The SRS airbags will deploy if the severi-
ty of the impact is above the designed
threshold level, comparable to an approxi-
mate 25 km/h (15 mph) collision when
impacting straight into a fixed barrier that
does not move or deform.
If the severity of the impact is below the
above threshold level, the SRS airbags
may not deploy. 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 it is involved in an underride
collision (e.g. a collision in which the nose
of the vehicle ºunderridesº, or goes under,
the bed of a truck, etc.).
It is possible with collision severity at the
marginal level of airbag sensor detection
and activation that only one of your ve-
hicle's two airbags will deploy.
For the safety of all occupants, be sure
to always wear seat belts.
Collision from thee rear
Collision from the side Vehicle rollover
The SRS airbags are not designed to
inflate if the vehicle is subjected to a
side or rear impact, if it rolls over, or
if it is involved in a low- speed frontal
collision.

4RUNNER ()
50
Hitting a curb,
edge of pavement
or hard material Falling into or
jumping over a
deep hole
Landing hard or vehicle falling
The SRS airbags may deploy if a seri-
ous impact occurs to the underside of
your vehicle. Some examples are shown
in the illustration.
The SRS airbag system mainly consists of
the following components and their loca-
tions are shown in the illustration. 1. Front airbag sensors
2. SRS airbag warning light
3. Airbag module for passenger (airbag and inflator)
4. Airbag sensor assembly
5. Airbag module for driver (airbag and inflator)
The airbag sensor assembly consists of a
safing sensor and airbag sensor. In a severe frontal impact, sensors detect
deceleration and the system triggers the
airbag inflators. Then a chemical reaction
in the inflators momentarily fills the air-
bags with non- toxic gas to help restrain
the forward 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 gas is nor-
mally harmless, however, for those who
have delicate skin, it may cause minor
skin irritation. Be sure to wash off any
residue as soon as possible to prevent
minor skin irritation.
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 swellings.
Parts of the airbag module (steering wheel
hub, dashboard) may be hot for several
minutes, but the airbags themselves will
not be hot. The airbags are designed to
inflate only once.

4RUNNER ()53
Do not allow a child to stand up,
or to kneel on the front passenger
seat. The airbag inflates with con-
siderable speed and force; the child
may be killed or seriously injured.
Do not hold a child on your lap or
in your arms. Use a child restraint
system in the rear seat. For instruc-
tions concerning the installation of
a child restraint system, see ºChild
restraintº in this chapter.Do not put objects or your pets on
or in front of the dashboard or
steering wheel pad that houses the
airbag system. They might restrict
inflation or cause death or serious
injury as they are projected rear-
ward by the force of deploying air-
bags. Likewise, the driver and front
passenger should not hold things 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, front passen-
ger airbag cover, front passenger
airbag or airbag sensor assembly.
Doing any of these may cause sud-
den SRS airbag inflation or disable
the system, which could result in
death or serious injury.
Failure to follow these instructions
can result in death or serious inju-
ries.

4RUNNER ()89
CAUTION
It is dangerous to continue driving
normally when the brake fluid level is
low.
If the brake fluid level is correct...
Have the warning system checked by your
Toyota dealer.
(b) Driver's Seat Belt Reminder Lightand Buzzer
Once the ignition key is turned to ºONº or
ºSTARTº, the reminder light flashes and
buzzer come on if the driver's seat belt
is not fastened. Unless the driver fastens
the belt, the light keeps on flashing and
the buzzer sounds for about 4 to 8 se-
conds.
(c) Front Passenger 's Seat Belt Re- minder Light
Once the ignition key is turned to ºONº or
ºSTARTº, the reminder light flashes if a
passenger sits in the front passenger seat
and does not fasten the seat belt. Unless
the front passenger fastens the belt, the
light stays flashing. If luggage load is placed on the front
passenger seat, depending on its weight
and how it is placed on the seat, built- in
sensors in the seat cushion may detect
the pressure, causing the reminder light to
come on.
(d) Discharge Warning Light
This light warns that the battery is being
discharged.
If it comes on while you are driving, there
is a problem somewhere in the charging
system.
The engine ignition will continue to oper-
ate, however, until the battery is dis-
charged. Turn off the air conditioning,
blower, radio, etc., and drive directly to
the nearest Toyota dealer or repair shop.
NOTICE
Do not continue driving if the engine
drive belt is broken or loose.
(e) Low Oil Pressure Warning Light
This light warns that the engine oil pres-
sure is too low.
If it flickers or stays on while you are
driving, pull off the road to a safe place
and stop the engine immediately. Call a
Toyota dealer or qualified repair shop for
assistance.
The light may occasionally flicker when
the engine is idling or it may come on
briefly after a hard stop. There is no
cause for concern if it then goes out when
the engine is accelerated slightly.
The light may come on when the oil level
is extremely low. It is not designed to
indicate low oil level, and the oil level
must be checked using the level dipstick.
NOTICE
Do not drive the vehicle with thewarning light onÐeven for one block.It may ruin the engine.

4RUNNER ()
90
(f) Malfunction Indicator Lamp
This lamp comes on in the following
cases.
a. The fuel tank is completely empty. (See
ºFuel gaugeº in Chapter 1- 5 for instruc-
tions.)
b. The fuel tank cap is not tightened se-
curely. (See ºFuel tank capº in Chapter
1- 2 for instructions.)
c. There is a problem somewhere in your
engine or automatic transmission electrical
system.
If it comes on while you are driving in
case c, have your vehicle checked/re-
paired by your Toyota dealer as soon as
possible.
(g) Low Fuel Level Warning Light
This light comes on when the fuel level
in the tank becomes nearly empty. Fill up
the tank as soon as possible.
On inclines or curves, due to the move-
ment of fuel in the tank, the low fuel level
warning light may come on earlier than
usual.
(h) ºABSº Warning Light
This light warns that there is a problem
somewhere in your anti- lock brake sys-
tem.
If the light comes on while you are driv-
ing, have your vehicle checked by your
Toyota dealer as soon as possible.
The light will come on when the ignition
key is turned to the ºONº position. After
a few seconds, the light will go off.
When the ºABSº warning light is on (and
the brake system warning light is off), the
brake system operates conventionally but
anti- lock brake system is not assisting
brake performance so that the wheels can
lock- up during sudden braking or braking
on slippery road surfaces.
Vehicles with rear differential lock sys-
temÐ
The anti- lock brake system does not oper-
ate when the rear differential is locked. It
is normal operation for the ºABSº warning
light to be on at this time.
(i) Open Door Warning Light
This light remains on until all the doors
and back door are completely closed.(j) SRS Airbag Warning Light
This light will come on when the igni-
tion key is turned to the ºACCº or
ºONº position. After about 6 seconds,
the light will go off. This means the
system of the airbag and front seat belt
pretensioner are operating properly.
The warning light system monitors the air-
bag sensor assembly, front airbag sen-
sors, seat belt pretensioner assemblies,
inflators, warning light, interconnecting wir-
ing and power sources.
If either of the following conditions occurs,
this indicates a malfunction somewhere in
the parts monitored by the warning light
system. Contact your Toyota dealer as
soon as possible to service the vehicle.
The light does not come on when the
ignition key is turned to the ºACCº or
ºONº position or remains on.
The light comes on or flashes while
driving.