ECU Lexus IS350 2018 / LEXUS 2018 IS300,IS350 (OM53E34U) User Guide

371-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
Your vehicle is equipped with ADVA NCED AIRBAGS designed based on the
US motor vehicle safety standards (F MVSS208). The airbag sensor assembly
(ECU) controls airbag deployment based on information obtained from the sen-
sors etc. shown in the system compon ents diagram above. This information
includes crash severity and occupant information. As the airbags deploy, a
chemical reaction in the inflators quickly fills the airbags with non-toxic gas to
help restrain the motion of the occupants.
SRS airbag system components
Front passenger occupant classifi-
cation system (ECU and sensors)
Side impact sensors (front doors)
Knee airbags
Front passenger airbag
Curtain shield airbags
“AIR BAG ON” and “AIR BAG
OFF” indicator lights
Seat belt pretensioners and force
limiters
Side impact sensors (front) Front side airbags
SRS warning light
Driver airbag
Rear side airbags
Side impact sensors (rear)
Driver’s seat position sensor
Driver’s seat belt buckle switch
Airbag sensor assembly
Front passenger’s seat belt buckle
switch
Front impact sensors1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

391-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
WARNING
■SRS airbag precautions
●The SRS front passenger airbag also deploy s with considerable force, 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 airbag as possible with the seatback
adjusted, so the front passenger sits upright.
●Improperly seated and/or restrained infant s 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 chil d restraint system. Lexus strongly recom-
mends that all infants and children be placed in the rear seats of the vehicle and prop-
erly restrained. The rear se ats are safer for infants and children than the front
passenger seat. ( →P. 53)
●If the seat belt extender has been connected
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 air-
bags will judge that the driver and front pas-
senger 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.
●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.

411-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
WARNING
■SRS airbag precautions
●Do not strike or apply significant levels of force to the area of the SRS airbag compo-
nents.
Doing so can cause the SRS airbags to malfunction.
●Do not touch any of the component part s immediately after the SRS airbags have
deployed (inflated) as they may be hot.
●If breathing becomes difficult after the SR S airbags have deployed, open a door or
window to allow fresh air in, or leave the vehicl e if it is safe to do so. Wash off any resi-
due as soon as possible to prevent skin irritation.
●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
Lexus 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 the sensor from detecting the pas-
senger’s weight properly. As a result, the SRS front airb ags 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 Lexus dealer. The SRS airb ags 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 pilla rs 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, ka ngaroo 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 radios and CD players
●Modifications to your vehicle for a person with a physical disability

431-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
■Conditions under which the SRS airbags may deploy (inflate), other than a collision
The SRS front airbags and SRS curtain shield airbags may also deploy if a serious impact
occurs to the underside of your vehicle. Some examples are shown in the illustration.
The SRS curtain shield airbags may also deploy under the situations shown in the illustra-
tion.
■Types of collisions that may not deploy the SRS airbags (SRS front airbags)
The SRS front airbags do not gene rally inflate if the vehicle is 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 sufficient forward deceleration of the vehicle, deployment of
the SRS front airbags may occur.
●Hitting a curb, edge of pavement or hard sur-
face
●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

451-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
■When to contact your Lexus dealer
In the following cases, the ve hicle will require inspection and/or repair. Contact your
Lexus 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 accident 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 acciden t that was not severe
enough to cause the SRS side and curtain
shield airbags to inflate.
●The pad section of the steering wheel, dash-
board near the front passenger airbag or
lower portion of the instrument panel is
scratched, cracked, or otherwise damaged.
●The surface of the seats with the side airbag is
scratched, cracked, or otherwise damaged.
●The portion of the front pillars, rear pillars or
roof side rail garnishes (padding) containing
the curtain shield airbags inside is scratched,
cracked, or otherwise damaged.

471-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
■Adult*1
■Child*4
Condition and operation in the front passenger occupant classification
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
Activated
Side airbag
on the front passenger seat
Curtain shield airbag
in the front passenger side
Front passenger knee airbag
Front passenger’s seat belt pretensioner
Indicator/
warning light
“AIR BAG ON” and “AIR BAG OFF” indicator lights“AIR BAG OFF” or “AIR BAG ON”
*4
SRS warning lightOff
Seat belt reminder lightOff*2 or flashing*3
Devices
Front passenger airbagDeactivated or activated
*4
Side airbag
on the front passenger seat
ActivatedCurtain shield airbag
in the front passenger side
Front passenger knee airbagDeactivated or activated
*4
Front passenger’s seat belt pretensionerActivated

491-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
■There is a malfunction in the system
*1: The system judges a person of adult size as an adult. When a smaller adult sits in
the front passenger seat, the system ma y not recognize him/her as an adult
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: For some children, child in seat, child in booster seat or child in convertible seat,
the system may not recognize him/her as a child. Factors which may affect this can
be the physique or posture.
*5: Never install a rear-facing child restraint system on the front passenger seat. A for-
ward-facing child restraint sy stem should only be installed on the front passenger
seat when it is unavoidable. (→ P. 53)
*6: In case the indicator light is not illuminated, consult this manual on how to install the
child restraint system properly. ( →P. 57)
Indicator/
warning light
“AIR BAG ON” and “AIR BAG OFF” indicator lights“AIR BAG OFF”
SRS warning light
On
Seat belt reminder light
Devices
Front passenger airbagDeactivated
Side airbag
on the front passenger seat
ActivatedCurtain shield airbag
in the front passenger side
Front passenger knee airbagDeactivated
Front passenger’s seat belt pretensionerActivated

511-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
WARNING
■Front passenger occupant classification system precautions
●Do not recline the front passenger seatback so far that it touches the rear seat. This
may cause the “AIR BAG OFF” indicator ligh t to be illuminated, which indicates that
the SRS airbags for the front passenger will not deploy in the event of a severe acci-
dent. If the seatback touches the rear seat, return the seatback to a position where it
does not touch the rear seat. Keep the fron t passenger seatback as upright as possi-
ble when the vehicle is moving. Reclining the seatback excessively may lessen the
effectiveness of the seat belt system.
●If an adult sits in the fron t passenger seat, the “AIR BAG ON” indicator light is illumi-
nated. If the “AIR BAG OFF” indicator is illuminated, 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” indicator still remain s illuminated, either ask the passenger to
move to the rear seat, or if that is not possible, move the front passenger seat fully
rearward.
●When it is unavoidable to in stall a forward-facing child re straint system on the front
passenger seat, install the ch ild restraint system on the front passenger seat in the
proper order. ( →P. 57)
●Do not modify or remove the front seats.
●Do not kick the front passenger seat or subject it to severe impact. Otherwise, the
SRS warning light may come on to indica te a malfunction of the front passenger
occupant classification system. In this cas e, contact your Lexus dealer immediately.
●Child restraint systems installed on the rear se at should not contact the front seat-
backs.
●Do not use a seat accessory, such as a cushion and seat cover, that covers the seat
cushion surface.
●Do not modify or replace the upholstery of the front seat.
●Do not place anything between the cons ole box and front passenger seat. Other-
wise, the system may not de tect the front passenger properly, leading to improper
operation of the airbags.
●Adjust the front passenger seat so that the head restraint does not touch the ceiling. If
the head restraint is left in contact with the ceiling, the system may not detect the front
passenger properly, leading to improper operation of the airbags.

531-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
Studies have shown that installing a child restraint on a rear seat is much safer
than installing one on the front passenger seat.
●Choose a child restraint system that su its your vehicle and is appropriate to
the age and size of the child.
●For installation details, follow the instru ctions provided with the child restraint
system.
General installation instructions are provided in this manual. ( →P. 57)
Child restraint systems
A child restraint system for a small ch ild or baby must itself be properly
restrained on the seat with the LATCH anchors or the lap portion of the lap/
shoulder belt.
The laws of all 50 states of the U.S.A. and Canada now require the use of child
restraint systems.
Points to remember

551-1. For safe use
1
For safety and security
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
WARNING
■Child restraint precautions
●For effective protection in automobile accidents and sudden stops, a child must be
properly restrained, using a seat belt or child restraint system depending on the age
and size of the child. Holding a child in your arms is not a su bstitute for a child restraint
system. In an accident, the child can be crushed against the windshield, or between
you and the vehicle’s interior. This may cause death or serious injury to the child in the
event of a sudden stop, sudden swerve or an accident.
●Lexus strongly urges the use of a proper ch ild restraint system that conforms to the
size of the child, installed on the rear seat. According to accident statistics, the child is
safer when properly restrained in th e rear seat than in the front seat.
●Never install a rear-facing child restraint sy stem on the front passenger seat even if
the “AIR BAG OFF” indicator light is illuminated.
In the event of an accident, the force of the rapid inflation of the front passenger air-
bag can cause death or serious injury to the child if the rear-facing child restraint sys-
tem is installed on th e front passenger seat.
●A forward-facing child restraint system ma y be installed on the front passenger seat
only when it is unavoidable. A child restraint system that requires a top tether strap
should not be used in the front passenger seat since there is no top tether strap
anchor for the front passenger seat. Adjust the seatback as upright as possible and
always move the seat as far back as possible even if the “AIR BAG OFF” indicator
light is illuminated, because the front passenger airbag co uld inflate with considerable
speed and force. Otherwise, the chil d may be killed or seriously injured.
●Do not use the seat belt extender when inst alling a child restraint system on the front
or rear passenger seat. If in stalling a child restraint system with the seat belt extender
connected to the seat belt, th e seat belt will not securely hold the child restraint sys-
tem, which could cause death or serious injury to the child or other passengers in the
event of a sudden stop, sudden swerve or accident.
●Do not allow the child to lean his/her head or any part of his/her body against the
door or the area of the seat, front, center an d rear pillars or roof side rails from which
the SRS side airbags or SRS cu rtain shield airbags deploy even if the child is seated in
the child restraint system. It is dangerous if the SRS side airbags and curtain shield air-
bags inflate, and the impact could caus e death or serious injury to the child.
●Make sure you have complied with all insta llation instructions provided by the child
restraint manufacturer and that the system is properly secured. If it is not secured
properly, it may cause death or serious inju ry to the child in the event of a sudden
stop, sudden swerve or an accident.