2021 LEXUS RX450h ECU

4527-2. Steps to take in an emergency
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■When removing the 12-volt battery ter-
minals
When the 12-volt battery terminals are
removed, the information stored in the
ECU is cleared. Before removing the
12-volt battery terminals, contact your
Lexus dealer.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradually even when the
vehicle is not in use, due to natural dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, and the hybrid system may be
unable to start. (The 12-volt battery
recharges automatically while the hybrid
system is operating.)
■When the 12-volt battery is removed or
discharged
●In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
12-volt battery is discharged. Use the
wireless remote control or the mechani-
cal key to lock or unlock the doors.
●The hybrid system may not start on the
first attempt after the 12-volt battery has
recharged but will start normally after the
second attempt. This is not a malfunction.
●The power switch mode is memorized by
the vehicle. When the 12-volt battery is
reconnected, the system will return to the
mode it was in before the 12-volt battery
was discharged. Before disconnecting
the 12-volt battery, turn the power switch
off.
If you are unsure what mode the power
switch was in before the 12-volt battery
discharged, be especially careful when
reconnecting the 12-volt battery.
●The power back door mu st be initialized.
(  P.119)
■When replacing the 12-volt battery
●RX450h: Use a Central Degassing type
12-volt battery (European Regulations). RX450hL: Use a 12-volt battery
designed for this vehicle.
●RX450h: Use a 12-volt battery that the
case size is same
as the previous one
(LN2), 20 hour rate capacity (20HR) is
equivalent (60Ah) or greater, and per-
formance rating (CCA) is equivalent
(460A) or greater.
• If the sizes differ, the 12-volt battery can- not be properly secured.
• If the 20 hour rate capacity is low, even if
the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and the hybrid system
may not be able to start.
●Use a 12-volt battery with a handle. If a
12-volt battery without a handle is used,
removal is more difficult.
●After replacing, firm ly attach the follow-
ing items to the exhaust hole of the
12-volt battery.
• Use the exhaust hose that was attached to the 12-volt battery before replacing
and confirm that it is firmly connected to
the hole section of the vehicle.
• Use the exhaust hole plug included with the 12-volt battery re placed or the one
installed on the 12-volt battery prior to
the replacement. (Depending on the
12-volt battery to be replaced, the
exhaust hole may be plugged.)
RX450h
Exhaust hole plug
Exhaust hole
A
B

4547-2. Steps to take in an emergency
“Engine Coolant Temp High Stop in
a Safe Place See Owner’s Manual”
is shown on the multi-information
display
1 Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2 If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has cooled
down sufficiently, inspect the hoses
WARNING
●Make sure to replace the 12-volt bat-
tery with one designed for this vehicle.
Otherwise, hydrogen gas may enter
the vehicle, possibly causing a fire or
explosion.
●After replacing, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the replaced
12-volt battery. If not properly installed,
gases (hydrogen) may leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.83)
enters the red zone, or a loss of
hybrid system power is experi-
enced. (For example, the vehicle
speed does not increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” or “Hybrid System
Overheated Output power
reduced” is shown on the
multi-information display.
 Steam comes out from under the
hood.
Correction procedures

4798-1. Specifications
8
Vehicle specifications
*: Table 1 -Occupant loading and distribution for vehicle normal load for various desig-nated seating capacities
Test rimThe rim on which a tire is fitted for testing, and may
be any rim listed as appropriate for use with that tire
TreadThat portion of a tire that comes into contact with
the road
Tread ribA tread section running ci rcumferentially around a
tire
Tread separationPulling away of the tread from the tire carcass
Treadwear indicators (TWI)
The projections within the principal grooves
designed to give a visual indication of the degrees
of wear of the tread
Wheel-holding fixtureThe fixture used to hold the wheel and tire assembly
securely during testing
Tire related termMeaning
Designated seating capac- ity, Number of occupantsVehicle normal load, Num- ber of occupantsOccupant distribution in a normally loaded vehicle
2 through 422 in front
5 through 1032 in front, 1 in second seat
11 through 1552 in front, 1 in second seat, 1 in third seat, 1 in fourth seat
16 through 2072 in front, 2 in second seat, 2 in third seat, 1 in fourth seat

4848-2. Customization
■Wireless remote control (P.107, 109, 113)
The doors that are unlocked
using the smart access system
with push-button start can be
selected
Driver’s doorAll the doorsO—O
Number of consecutive door
lock operations2 timesAs many as desired——O
FunctionDefault settingCustomized setting
Wireless remote controlOnOff——O
Unlocking operation
Driver’s door
unlocked in one step, all doors
unlocked in two step
All doors unlocked in one stepO—O
Panic functionOnOff——O
FunctionDefault settingCustomized settingABC
ABC

4969-1. For owners
9-1.For owners
Déroulez la sangle diagonale de
telle sorte qu'elle passe bien sur
l'épaule, sans pour autant être en
contact avec le cou ou glisser de
l'épaule.
 Placez la sangle abdominale le plus
bas possible sur les hanches.
 Réglez la position du dossier de
siège. Asseyez-vous le dos droit et
calez-vous bien dans le siège.
 Ne vrillez pas la ceinture de sécu-
rité.
Reporting safety defects for
U.S. owners
If you believe that your vehicle has a
defect which could cause a crash or
could cause injury or death, you
should immediately inform the
National Highway Traffic Safety
Administration (NHTSA) in addition
to notifying the Lexus Division of
Toyota Motor Sales, U.S.A., Inc.
(Toll-free: 1-800-25-LEXUS).
If NHTSA receives similar com-
plaints, it may open an investigation,
and if it finds that a safety defect
exists in a group of vehicles, it may
order a recall and remedy campaign.
However, NHTSA cannot become
involved in individual problems
between you, your dealer, or Lexus
Division of Toyota Motor Sales,
U.S.A., Inc.
To contact NHTSA, you may call the
Vehicle Safety Hotline toll-free at
1-888-327-4236 (TTY:
1-800-424-9153); go to
http://www.safercar.gov ; or write to:
Administrator, NHTSA, 1200 New
Jersey Ave. SE., Washington, DC
20590. You can also obtain other
information about motor vehicle
safety from
http://www.safercar.gov.
Seat belt instructions for
Canadian owners (in French)
The following is a French explana-
tion of seat belt instructions
extracted from the seat belt section
in this manual.
See the seat belt section for more
detailed seat belt instructions in
English.
Utilisation correcte des cein-
tures de sécurité

4979-1. For owners
9
For owners
■Traitement des ceintures de sécu-
rité
Nettoyez avec un chiffon ou une
éponge humidifiés avec de l'eau savon-
neuse tiède. Vérifiez régulièrement
que les ceintures ne sont pas usées,
effilochées ou entaillées excessive-
ment.
Entretien et soin
WARNING
■Détérioration et usure des ceintures
de sécurité
Inspectez le système de ceintures de
sécurité régulière ment. Contrôlez
l'absence de coupures, d'effilochages et
de pièces desserrées. N'utilisez pas une
ceinture de sécurité endommagée avant
qu'elle ne soit remplacée. Une ceinture
de sécurité endommagée ne permet pas
de protéger un occupant de blessures
graves ou mortelles.

5009-1. For owners
Coussins gonflables rideaux SRS
• Participent principalement à la protection de la tête des occupants des sièges latéraux
• Peut contribuer à empêcher les occupants d’être éjectés du véhicule en cas de tonneau
■Composants du système de coussins gonflables SRS
Coussin gonflable passager avant
Témoins indicateurs “AIR BAG ON” et “AIR BAG OFF”
Coussins gonflables latéraux avant
Coussins gonflables rideaux
Capteurs d'impact latéral (arrière)
Témoin d'avertissement SRS
Système de classification de l'occupant du siège passager avant (ECU et cap-
teurs)
Coussin gonflable conducteur
Capteurs d'impact latéral (porte avant)
Prétensionneurs de ceintures de sécurité et limiteurs de force
Coussin gonflable de coussin de siège passager
Capteur de position du siège conducteur
Coussin gonflable de genoux du conducteur
Contact de boucle de ceinture de sécurité conducteur
Capteurs d'impact avant
Ensemble de capteurs de coussins gonflables
RX450h: Coussins gonflables latéraux arrière
F
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q

5019-1. For owners
9
For owners
RX450hL: Coussins gonflables latéraux arrière (sièges latéraux de deuxième
rangée)
Votre véhicule est équipé de CO USSINS GONFLABLES INTELLIGENTS
conçus selon les normes de sécurité américaines applicables aux véhicules à
moteur (FMVSS208). L'ensemble de cap teurs de coussins gonflables (ECU)
régule le déploiement des coussins gonfla bles sur la base des informations qu'il
reçoit des capteurs, etc., indiqués ci-dessus dans le schéma illustrant les com-
posants du système. Parmi ces informations figurent la gravité du choc et l'occupa-
tion du véhicule par les passagers. Le déploiement rapide des coussins gonflables
est obtenu au moyen d'une réaction chimique dans les dispositifs pyrotechniques,
qui produit un gaz inoffensif permettant d'amortir le mouvement des occupants.
WARNING
■Précautions relatives aux coussins
gonflables SRS
Respectez les précautions suivantes
concernant les coussins gonflables SRS.
Le non-respect de ces précautions peut
occasionner des blessures graves, voire
mortelles.
●Le conducteur et tous les passagers du
véhicule doivent porter correctement
leur ceinture de sécurité.
Les coussins gonflables SRS sont des
dispositifs supplémentaires à utiliser
avec les ceinture s de sécurité.
●Le coussin gonflable conducteur SRS
se déploie avec une force con-
sidérable, pouvant occasionner des
blessures graves, voire mortelles, si le
conducteur se trouve très près du
coussin gonflable.
L'autorité fédérale chargée de la sécu-
rité routière aux États-Unis (NHTSA)
conseille: La zone à risque du coussin
gonflable conducteur se situant dans
les premiers 2 à 3 in. (50 à 75 mm) de
déploiement, vous placer à 10 in. (250
mm) de votre coussin gonflable con-
ducteur vous garantit une marge de
sécurité suffisante. Cette distance est
à mesurer entre le centre du volant et
le sternum. Si vous êtes assis à moins
de 10 in. (250 mm), vous pouvez
changer votre position de conduite de
plusieurs façons:
• Reculez votre siège le plus possible, de manière à pouvoir encore atteindre
confortablement les pédales.