2021 TOYOTA 4RUNNER ECU

341-1. For safe use
4RUNNER (U)
WARNING
■Seat belt damage and wear
● Do not damage the seat belts by allowing the belt, plate, or bu ckle to be
jammed in the door.
● Inspect the seat belt system periodically. Check for cuts, fray ing, and loose
parts. Do not use a damaged seat belt until it is replaced. Dam aged seat
belts cannot protect an occupant from death or serious injury.
● Ensure that the belt and plate are locked and the belt is not twisted.
If the seat belt does not function correctly, immediately conta ct your Toyota
dealer.
● Replace the seat assembly, including the belts, if your vehicle has been
involved in a serious accident, even if there is no obvious dam age.
● Do not attempt to install, remove, modify, disassemble or dispo se of the
seat belts. Have any necessary repairs carried out by your Toyota dealer.
Inappropriate handling may lead to incorrect operation.
■ Using a seat belt extender
● Do not wear the seat belt extender if you can fasten the seat belt without
the extender.
● Do not use the seat belt extender when installing a child restr aint system
because the belt will not securely hold the child restraint system, increas-
ing the risk of death or serious injury in the event of an acci dent.
● The personalized extender may not be safe on another vehicle, when
used by another person, or at a different seating position othe r than the
one originally intended.
NOTICE
■ When using a seat belt extender
When releasing the seat belt, press on the buckle release butto n on the
extender, not on the seat belt.
This helps prevent damage to the vehicle interior and the extender itself.

351-1. For safe use
1
For safety and security
4RUNNER (U)
◆SRS front airbagsSRS driver airbag/front passenger airbag
Can help protect the head and c hest of the driver and front pas-
senger from impact with interior components
SRS knee airbags
Can help provide driver and front passenger protection
◆SRS side and curta in shield airbags
SRS side airbags
Can help protect the torso o f the front seat occupants
SRS curtain sh ield airbags
● Can help protect primarily the head of occupants in the outer
seats
● Can help prevent the occupants from being thrown from the
vehicle in the event of vehicle rollover
SRS airbags
The SRS airbags inflate when th e vehicle is subjected to certain
types of severe impacts that may cause significant injury to th e
occupants. They work together wit h the seat belts to help reduce
the risk of death or serious injury.
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4

361-1. For safe use
4RUNNER (U)
SRS airbag system components
Side airbags
“AIR BAG ON” and “AIR BAG
OFF” indicator lights
Curtain shield airbags
Front passenger airbag
Knee airbags
Side impact sensors (front
door)
Seat belt pretensioners and
force limiters
Front impact sensors
Airbag sensor assemblyFront passenger’s seat belt
buckle switch
Front passenger occupant
classification system (ECU
and sensors)
Side impact sensors (rear)
SRS warning light
Safing sensor (rear)
Driver airbag
Driver’s seat belt buckle
switch1
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4
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6
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9
10
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15
16

371-1. For safe use
1
For safety and security
4RUNNER (U)
Your vehicle is equipped with ADVANCED AIRBAGS designed based
on the US motor vehicle safety standards (FMVSS208). The airbag
sensor assembly (ECU) controls airbag deployment based on infor-
mation obtained from the sensors etc. shown in the system compo -
nents diagram above. This informat ion includes crash severity and
occupant information. As the airbags deploy, a chemical reactio n in
the inflators quickly fills the airbags with non-toxic gas to h elp restrain
the motion of t he occupants.
WARNING
■SRS airbag precautions
Observe the following precautions regarding the SRS airbags.
Failure to do so may cause death or serious injury.
● The driver and all passengers in the vehicle must wear their se at belts
properly.
The SRS airbags are supplemental devices to be used with the se at belts.
● The SRS driver airbag deploys with considerable force, and can cause
death or serious injury especially if the driver is very close to the airbag.
The National Highway Traffic Safety Administration (NHTSA) advi ses:
Since the risk zone for the driver’s airbag is the first 2 - 3 in. (50 - 75 mm)
of inflation, placing yourself 10 in. (250 mm) from your driver airbag pro-
vides you with a clear margin of safety. This distance is measured from
the center of the steering wheel to your breastbone. If you sit less than 10
in. (250 mm) away now, you can change your driving position in several
ways:
• Move your seat to the rear as far as you can while still reach ing the ped-
als comfortably.
• Slightly recline the back of the seat.
Although vehicle designs vary, many drivers can achieve the 10 in. (250
mm) distance, even with the driver seat all the way forward, si mply by
reclining the back of the seat somewhat. If reclining the back of your
seat makes it hard to see the road, raise yourself by using a f irm, non-
slippery cushion, or raise the seat if your vehicle has that feature.
• If your steering wheel is adjustable, tilt it downward. This points the air-
bag toward your chest instead of your head and neck.
The seat should be adjusted as recommended by NHTSA above, whil e
still maintaining control of the foot pedals, steering wheel, and your view
of the instrument panel controls.

381-1. For safe use
4RUNNER (U)
WARNING
■SRS airbag precautions
● The SRS front passenger airbag also deploys with considerable f orce, and
can cause death or serious injury especially if the front passe nger is very
close to the airbag. The front passenger seat should be as far from the air-
bag as possible with the seatback adjusted, so the front passenger sits
upright.
● Improperly seated and/or restrained infants and children can be killed or
seriously injured by a deploying airbag. An infant or child who is too small
to use a seat belt should be properly secured using a child restraint sys-
tem. Toyota strongly recommends that all infants and children b e placed in
the rear seats of the vehicle and properly restrained. The rear seats are
safer for infants and children than the front passenger seat. ( P. 53)
●If the seat belt extender has been con-
nected to the front seat belt buckles but
the seat belt extender has not also been
fastened to the latch plate of the seat
belt, the SRS front airbags will judge
that the driver and front passenger are
wearing the seat belt even though the
seat belt has not been connected. In
this case, the SRS front airbags may
not activate correctly in a collision,
resulting in death or serious injury in the
event of a collision. Be sure to wear the
seat belt with the seat belt extender.
●Do not sit on the edge of the seat or
lean against the dashboard.

391-1. For safe use
1
For safety and security
4RUNNER (U)
WARNING
■SRS airbag precautions
● Do not allow a child to stand in front of
the SRS front passenger airbag unit or
sit on the knees of a front passenger.
● Do not allow the front seat occupants to
hold items on their knees.
● Do not lean against the door, the roof
side rail or the front, side and rear pil-
lars.
● Do not allow anyone to kneel on the
passenger seats toward the door or put
their head or hands outside the vehicle.
● Do not attach anything to or lean any-
thing against areas such as the dash-
board, steering wheel pad and lower
portion of the instrument panel.
These items can become projectiles
when the SRS driver, front passenger
and knee airbags deploy.
● Do not attach anything to areas such as
a door, windshield glass, side door
glass, front or rear pillar, roof side rail
and assist grip.

411-1. For safe use
1
For safety and security
4RUNNER (U)
■If the SRS airbags deploy (inflate)
●Slight abrasions, burns, bruising etc., may be sustained from S RS airbags,
due to the extremely high speed deployment (inflation) by hot g ases.
● A loud noise and white powder will be emitted.
● Parts of the airbag module (steering wheel hub, airbag cover an d inflator) as
well as the front seats, parts of the front and rear pillars, and roof side rails
may be hot for several minutes. The airbag itself may also be h ot.
● The windshield may crack.
● Fuel supply to the engine will be stopped. ( P. 473)
● For Safety Connect subscribers, if any of the following situations occur, the
system is designed to send an emergency call to the response center, noti-
fying them of the vehicle's location (without needing to push t he “SOS” but-
ton) and an agent will attempt to speak with the occupants to a scertain the
level of emergency and assistance required. If the occupants are unable to
communicate, the agent automatically treats the call as an emer gency and
helps to dispatch the necessary emergency services. ( P. 70)
• An SRS airbag is deployed.
• A seat belt pretensioner is activated.
• The vehicle is involved in a severe rear-end collision.
• The vehicle is involved in a rollover accident.
WARNING
■ Modification and disposal of SRS airbag system components
Do not dispose of your vehicle or perform any of the following modifications
without consulting your Toyota dealer. The SRS airbags may malfunction or
deploy (inflate) accidentally, causing death or serious injury.
● Installation, removal, disassembly and repair of the SRS airbag s
● Repairs, modifications, removal or replacement of the steering wheel,
instrument panel, dashboard, seats or seat upholstery, front, s ide and rear
pillars or roof side rails
● Repairs or modifications of the front fender, front bumper, or side of the
occupant compartment
● Installation of a grill guard (bull bars, kangaroo bar etc.), s now plows,
winches or roof luggage carrier.
● Modifications to the vehicle’s suspension system
● Installation of electronic devices such as mobile two-way radio s and CD
players
● Modifications to your vehicle for a person with a physical disa bility

431-1. For safe use
1
For safety and security
4RUNNER (U)■
Conditions under which the SRS ai rbags may deploy (inflate), other than
a collision
The SRS front airbags, SRS side and curtain shield airbags may also deploy
if a serious impact occurs to the underside of your vehicle. So me examples
are shown in the illustration.
The SRS curtain shield airbags may also deploy under the situat ions shown
in the illustration.
■ Types of collisions that may not deploy the SRS airbags (SRS fr ont air-
bags)
The SRS front airbags do not generally inflate if the vehicle i s involved in a
side or rear collision, if it rolls over, or if it is involved in a low-speed frontal
collision. But, whenever a collision of any type causes suffici ent forward
deceleration of the vehicle, deployment of the SRS front airbag s may occur.
●
Hitting a curb, edge of pavement or hard
surface
● Falling into or jumping over a deep hole
● Landing hard or falling
● The angle of vehicle tip-up is marginal.
● The vehicle skids and hits a curb stone.
● Collision from the side
● Collision from the rear
● Vehicle rollover