2021 TOYOTA TUNDRA ECU

371-1. For safe use
1
For safety and security
WARNING
Observe the following precautions to reduce the risk of injury in the event of
sudden braking, sudden swerving or an accident.
Failure to do so may cause death or serious injury.
■ Wearing a seat belt
● Ensure that all passengers wear a seat belt.
● Always wear a seat belt properly.
● Each seat belt should be used by one person only. Do not use a seat belt
for more than one person at once, including children.
● Toyota recommends that children be seated in the rear seat and always
use a seat belt and/or an appropriate child restraint system.
● To achieve a proper seating position, do not recline the seat m ore than
necessary. The seat belt is most effective when the occupants a re sitting
up straight and well back in the seats.
● Do not wear the shoulder belt under your arm.
● Always wear your seat belt low and snug across your hips.
■ Pregnant women
■ People suffering illness
Obtain medical advice and wear the seat belt in the proper way. (P. 34)
Obtain medical advice and wear the seat
belt in the proper way. ( P. 34)
Women who are pregnant should posi-
tion the lap belt as low as possible over
the hips in the same manner as other
occupants, extending the shoulder belt
completely over the shoulder and avoid-
ing belt contact with the rounding of the
abdominal area.
If the seat belt is not worn properly, not
only the pregnant woman, but also the
fetus could suffer death or serious injury
as a result of sudden braking or a colli-
sion.

391-1. For safe use
1
For safety and security
WARNING
■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 sys tem, 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.

411-1. For safe use
1
For safety and security
◆SRS front airbags
SRS driver airbag/front passenger airbag
Can help protect the head and chest of the driver and right front
passenger from impact w ith 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 fro m being thrown from the vehi-
cle in the event of vehicle rollover
1
2
3
4

421-1. For safe use
SRS airbag system components
Seat belt pretensioners
Knee airbags
“AIR BAG ON” and “AIR BAG
OFF” indicator lights
Front passenger airbag
Curtain shield airbags
Side airbags (front seats)
Front passenger occupant
classification system (ECU
and sensors)
SRS warning lightDriver airbag
Driver’s seat p
osition sensor
Side impact sensors (rear)
Side impact sensors (front
door)
Driver’s seat belt buckle
switch
Front passenger’s seat belt
buckle switch
Front impact sensors
Airbag sensor assembly1
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3
4
5
6
7
8
9
10
11
12
13
14
15
16

431-1. For safe use
1
For safety and security
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.
Front bench type seat: The SRS airbags are designed to protect the
driver and right front passenger, and they are not designed to protect
an occupant in the front c enter seating position.

451-1. For safe use
1
For safety and security
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 res traint 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. 59)
●Do not sit on the edge of the seat or
lean against the dashboard.
● 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.

471-1. For safe use
1
For safety and security
WARNING
■SRS airbag precautions
● Do not use seat accessories which cover the parts where the SRS side
airbags inflate as they may interfere with inflation of the air bags. Such
accessories may prevent the side airbags from activating correc tly, disable
the system or cause the side airbags to inflate accidentally, r esulting in
death or serious injury.
● Do not strike or apply significant levels of force to the area of the SRS air-
bag components.
Doing so can cause the SRS airbags to malfunction.
● Do not touch any of the component parts immediately after the S RS air-
bags have deployed (inflated) as they may be hot.
● If breathing becomes difficult after the SRS airbags have deplo yed, open a
door or window to allow fresh air in, or leave the vehicle if i t is safe to do
so. Wash off any residue as soon as possible to prevent skin ir ritation.
● If the areas where the SRS airbags are stored, such as the steering wheel
pad and front and rear pillar garnishes, are damaged or cracked , have
them replaced by your Toyota dealer.
● Do not place anything, such as a cushion, on the front passenger’s seat.
Doing so will disperse the passenger’s weight, which prevents t he sensor
from detecting the passenger’s weight properly. As a result, th e SRS front
airbags for the front passenger may not deploy in the event of a collision.
■ 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 grille guard (bull bars, kangaroo bar, etc.), snow 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

491-1. For safe use
1
For safety and security
■SRS airbag deployment condi tions (SRS front airbags)
● The SRS front airbags will deploy in the event of an impact tha t exceeds the
set threshold level (the level of force corresponding to an app roximately
12 - 18 mph [20 - 30 km/h] frontal collision with a fixed wall that does not
move or deform).
However, this threshold velocity will be considerably higher in the following
situations:
• If the vehicle strikes an object, such as a parked vehicle or sign pole, which
can move or deform on impact
• If the vehicle is involved in an underride collision, such as a collision in
which the front of the vehicle “underrides”, or goes under, the bed of a truck
● Depending on the type of collision, it is possible that only th e seat belt pre-
tensioners will activate.
● The SRS front airbags for the front passenger will not activate if there is no
passenger sitting in the right front passenger seat. However, t he SRS front
airbags for the front passenger may deploy if luggage is put in the seat,
even if the seat is unoccupied. ( P. 53)
■ SRS airbag deployment conditions (SRS side and curtain shield airbags)
● The SRS side and curtain shield airbags will deploy in the even t of an
impact that exceeds the set threshold level (the level of force corresponding
to the impact force produced by an approximately 3300 lb. [1500 kg] vehicle
colliding with the vehicle cabin from a direction perpendicular to the vehicle
orientation at an approximate speed of 12 - 18 mph [20 - 30 km/ h]).
● The SRS curtain shield airbags will deploy in the event of vehi cle rollover.
● The SRS curtain shield airbags may also deploy in the event of a severe
frontal collision.