ECU TOYOTA 4RUNNER 2023 User Guide

381-1. 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
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

391-1. 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 information includes crash severity a nd
occupant information. As the airbags deploy, a chemical reaction 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 firm, 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, while
still maintaining control of the foot pedals, steering wheel, and your view
of the instrument panel controls.

401-1. 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 passenger 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. 55)
●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.

411-1. 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.

431-1. 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 gases.
● A loud noise and white powder will be emitted.
● Parts of the airbag module (steering wheel hub, airbag cover and 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. 476)
● For Safety Connect subscribers, if any of the following situati ons 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 ascertain the
level of emergency and assistance required. If the occupants are unable to
communicate, the agent automatically treats the call as an emergency and
helps to dispatch the necessary emergency services. ( P. 72)
• 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 airbags
● Repairs, modifications, removal or replacement of the steering wheel,
instrument panel, dashboard, seats or seat upholstery, front, side 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 disability

451-1. 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

471-1. For safe use
1
For safety and security
4RUNNER (U)■
When to contact your Toyota dealer
In the following cases, the vehicle will require inspection and/or repair. Con-
tact your Toyota dealer as soon as possible.
●Any of the SRS airbags have been inflated.
● The front of the vehicle is damaged or
deformed, or was involved in an acci-
dent that was not severe enough to
cause the SRS front airbags to inflate.
● A portion of a door or its surrounding
area is damaged or deformed, or the
vehicle was involved in an accident that
was not severe enough to cause the
SRS side and curtain shield airbags to
inflate.
● The pad section of the steering wheel,
dashboard near the front passenger air-
bag or lower portion of the instrument
panel is scratched, cracked, or other-
wise damaged.
● The surface of the seats with the SRS
side airbag is scratched, cracked, or oth-
erwise damaged.
● The portion of the front pillars, rear pil-
lars or roof side rail garnishes (padding)
containing the SRS curtain shield air-
bags inside is scratched, cracked, or
otherwise damaged.

491-1. For safe use
1
For safety and security
4RUNNER (U)■
Adult*1
■Child*4 or child restraint system*5
Condition and operation in the front passenger occupant classi-
fication system
Indicator/
warning light
“AIR BAG ON” and “AIR BAG OFF” indicator lights“AIR BAG ON”
SRS warning lightOff
Seat belt reminder lightOff*2 or
flashing
*3
Devices
Front passenger airbag
ActivatedFront passenger knee airbag
Front passenger's seat belt pretensioner
Indicator/
warning light
“AIR BAG ON” and “AIR BAG OFF” indicator lights“AIR BAG OFF”
*6
SRS warning lightOff
Seat belt reminder lightFlashing*3
Devices
Front passenger airbag
Deactivated
Front passenger knee airbag
Front passenger's seat belt pretensionerActivated

511-1. For safe use
1
For safety and security
4RUNNER (U)■
There is a malfunction in the system
*1: The system judges a person of adult size as an adult. When a s
maller
adult sits in the front passenger seat, the system may recognize him/her
as a child depending on his/her physique and posture.
*2: In the event the front passenger is wearing a seat belt.
*3: In the event the front passenger does not wear a seat belt.
*4: When a larger child who has outgrown a child restraint system sits in the front passenger seat, the system may recognize him/her as an ad ult
depending on his/her physique or posture.
*5: Never install a rear-facing child restraint system on the front passenger seat. A forward-facing child restraint system should only be installed on
the front passenger seat when it is unavoidable.
(P. 55)
*6: In case the indicator light is not illuminated, consult this manual on how
to install the child restraint system properly. ( P. 59)
*7: In the event of a side collision.
*8: In the event of a frontal collision or rollover.
Indicator/
warning light
“AIR BAG ON” and “AIR BAG OFF” indicator lights“AIR BAG OFF”
SRS warning lightOn
Seat belt reminder lightOn or flashing
Devices
Front passenger airbag
Deactivated
Front passenger knee airbag
Front passenger's seat belt pretensionerActivated

531-1. For safe use
1
For safety and security
4RUNNER (U)
WARNING
■Front passenger occupant classification system precautions
● Do not recline the front passenger seatback so far that it touches a rear
seat. This may cause the “AIR BAG OFF” indicator light to be il luminated,
which indicates that the SRS airbags for the front passenger wi ll not
deploy in the event of a severe accident. If the seatback touches the rear
seat, return the seatback to a position where it does not touch the rear
seat. Keep the front passenger seatback as upright as possible when the
vehicle is moving. Reclining the seatback excessively may lesse n the
effectiveness of the seat belt system.
● If an adult sits in the front passenger seat, the “AIR BAG ON” indicator
light is illuminated. If the “AIR BAG OFF” indicator is illumin ated, ask the
passenger to sit up straight, well back in the seat, feet on the floor, and
with the seat belt worn correctly. If the “AIR BAG OFF” indicat or still
remains illuminated, either ask the passenger to move to the re ar seat, or
if that is not possible, move the front passenger seat fully re arward.
● When it is unavoidable to install a forward-facing child restraint system on
the front passenger seat, install the child restraint system on the front pas-
senger seat in the proper order. ( P. 59)
● Do not modify or remove the front seats.
● Do not kick the front passenger seat or subject it to severe im pact. Other-
wise, the SRS warning light may come on to indicate a malfunction of the
front passenger occupant classification system. In this case, contact your
Toyota dealer immediately.
● Child restraint systems installed on the second seat should not contact the
front seatbacks.
● Do not use a seat accessory, such as a cushion and seat cover, that cov-
ers the seat cushion surface.
● Do not modify or replace the upholstery of the front seat.