warning LEXUS RX450h 2021 Owners Manual

4537-2. Steps to take in an emergency
7
When trouble arises
Exhaust hose
Hole section of the vehicle
RX450hLExhaust hole
Exhaust hose
Hole section of the vehicle
●For details, consult your Lexus dealer.
WARNING
■When removing the 12-volt battery
terminals
Always remove the negative (-) terminal
first. If the positive (+) terminal contacts
any metal in the surrounding area when
the positive (+) terminal is removed, a
spark may occur, leading to a fire in addi-
tion to electrical shocks and death or
serious injury.
■Avoiding 12-volt battery fires or
explosions
Observe the following precautions to
prevent accidentally igniting the flamma-
ble gas that may be emitted from the
12-volt battery:
●Make sure each jumper cable is con-
nected to the correct terminal and that
it is not unintentiona lly in contact with
any other than the intended terminal.
●Do not allow the other end of the
jumper cable connected to the “+” ter-
minal to come into contact with any
other parts or metal surfaces in the
area, such as brackets or unpainted
metal.
C
D
A
B
C
●Do not allow the + and - clamps of the
jumper cables to come into contact
with each other.
●Do not smoke, use matches, cigarette
lighters or allow open flame near the
12-volt battery.
■12-volt battery precautions
The 12-volt battery contains poisonous
and corrosive acidic electrolyte, while
related parts contain lead and lead com-
pounds. Observe the following precau-
tions when handling the 12-volt battery:
●When working with the 12-volt battery,
always wear safety glasses and take
care not to allow any battery fluids
(acid) to come into contact with skin,
clothing or the vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid comes
into contact with the skin or eyes,
immediately wash the affected area
with water and seek medical attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.
●Always wash your ha nds after handling
the 12-volt battery support, terminals,
and other battery-related parts.
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.
■When replacing the 12-volt battery
●When the vent plug and indicator are
close to the hold down clamp, the bat-
tery fluid (sulfuric acid) may leak.
●For information regarding 12-volt bat-
tery replacement, contact your Lexus
dealer.

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

4567-2. Steps to take in an emergency
Lexus dealer.
If “Hybrid System Overheated Out-
put power reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe place.
2 Stop the hybrid system and care-
fully lift the hood.
3 After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line 5
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
6Start the hybrid system and check if
“Hybrid System Overheated Out-
put power reduced” is shown on
the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact
your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Lexus dealer.
A
B
A
B
C
WARNING
■When inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.

4577-2. Steps to take in an emergency
7
When trouble arises
1Stop the hybrid system. Shift the
shift lever to P and set the parking
brake.
2 Remove the mud, snow or sand
from around the front wheels.
3 Place wood, stones or some other
material under the front wheels to
help provide traction.
4 Restart the hybrid system.
5 Shift the shift lever to D or R and
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press to turn off TRAC.
WARNING
●After the hybrid system has been
turned off, check that the “READY”
indicator is off.
When the hybrid system is operating,
the gasoline engine may automatically
start, or the cooling fans may suddenly
operate even if the gasoline engine
stops. Do not touch or approach rotat-
ing parts such as the fans, which may
lead to fingers or cl othing (especially a
tie, a scarf or a muffler) getting caught,
resulting in serious injury.
●Do not loosen the radiator cap and the
coolant reservoir caps while the hybrid
system and radiator are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine/power control
unit coolant
Add coolant slowly after the hybrid sys-
tem has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too
quickly can cause damage to the hybrid
system.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust,
etc.).
●Do not use any coolant additive.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure

4587-2. Steps to take in an emergency
WARNING
■When attempting to free a stuck vehi-
cle
If you choose to push the vehicle back
and forth to free it, make sure the sur-
rounding area is clear to avoid striking
other vehicles, objects or people. The
vehicle may also lunge forward or lunge
back suddenly as it becomes free. Use
extreme caution.
■When shifting the shift lever
Be careful not to shif t the shift lever with
the accelerator pedal depressed.
This may lead to unexpected rapid accel-
eration of the vehicle that may cause an
accident resulting in death or serious
injury.
NOTICE
■To avoid damage to the hybrid trans-
mission and other components
●Avoid spinning the front wheels and
depressing the accelerator pedal
more than necessary.
●If the vehicle remains stuck even after
these procedures are performed, the
vehicle may require towing to be freed.

4748-1. Specifications
Your Lexus dealer will help answer any
questions you may have as you read this
information.
■DOT quality grades
All passenger vehicle tires must con-
form to Federal Safety Requirements in
addition to these grades. Quality
grades can be found where applicable
on the tire sidewall between tread
shoulder and maximum section width.
For example: Treadwear 200 Traction AA
Temperature A
■Treadwear
The treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would wear
one and a half (1 - 1/2) times as well on the
government course as a tire graded 100.
The relative performa nce of tires depends
upon the actual conditions of their use.
Performance may differ significantly from
the norm due to variatio ns in driving habits,
service practices and differences in road
characteristics and climate.
■Traction AA, A, B, C
The traction grades, from highest to
lowest, are AA, A, B and C, and they
represent the tire’s ability to stop on
wet pavement as measured under con-
trolled conditions on specified govern-
ment test surfaces of asphalt and
concrete.
A tire marked C may have poor traction
performance.
Warning: The traction grade assigned to
this tire is based on braking (straight ahead) traction tests and does not include
cornering (turning) traction.
■Temperature A, B, C
The temperature grades are A (the
highest), B, and C, representing the
tire’s resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Sustained high temperature can cause the
material of the tire to degenerate and
reduce tire life, and excessive temperature
can lead to sudd en tire failure.
Grade C corresponds to a level of perfor-
mance which all passenger car tires must
meet under the Fede ral Motor Vehicle
Safety Standard No. 109.
Grades B and A represent higher levels of
performance on the laboratory test wheel
than the minimum required by law.
Warning: The temperature grades of a tire
assume that it is properly inflated and not
overloaded.
Excessive speed, unde rinflation, or exces-
sive loading, either separately or in combi-
nation, can cause heat buildup and
possible tire failure.

4808-2. Customization
8-2.Customization
■Changing by using the Remote
Touch
1 Press the “MENU” button on the
Remote Touch.
2 Select “Setup” on the menu screen
and select “Vehicle”.
3 Select “Vehicle Customization” or
“Drive Mode Customization”.
Various setting can be changed. Refer to
the list of settings that can be changed for
details.
This system can also be operated by the
touch screen.
For details on the Remote Touch, refer
to the “NAVIGATION AND MULTI-
MEDIA SYSTEM OWNER’S MAN- UAL”.
■Changing by using the meter con-
trol switches
1 Press or to select .
2 Operate the meter control
switches to select the desired item
to be customized.
3 According to the display, select the
desired setting and then press
.
To go back to the previous screen or exit
the customize mode, press .
Some function settings are changed simultaneously with other functions being cus-
tomized. Contact your Lexus dealer for further details.
Settings that can be changed using the Remote Touch
Settings that can be changed using the meter control switches
Settings that can be changed by your Lexus dealer
Definition of symbols: O = Available, — = Not available
Customizable features
Your vehicle includes a variety of
electronic features that can be per-
sonalized to suit your preferences.
The settings of these features can
be changed by using the meter con-
trol switches, the Remote Touch, or
at your Lexus dealer.
Customizing vehicle features
WARNING
■During customization
As the hybrid system needs to be operat-
ing during customizatio n, ensure that the
vehicle is parked in a place with ade-
quate ventilation. In a closed area such as
a garage, exhaust gases including harm-
ful carbon monoxide (CO) may collect
and enter the vehicle. This may lead to
death or a serious health hazard.
NOTICE
■During customization
To prevent 12-volt battery discharge,
ensure that the hybrid system is operat-
ing while customizing features.
Customizable Features
A
B
C

4838-2. Customization
8
Vehicle specifications
■Power back door (P.113)
*:If equipped
■Smart access system with push-button start and wireless remote control
( P.109, 125)
■Smart access system with push-button start ( P.109, 125)
FunctionDefault settingCustomized setting
Power back doorOnOff—O—
Power back door opening
position51 to 5O——
Buzzer volumeLevel 3Level 1—O—Level 2
Kick sensor*OnOff—O—
Hands free close & lock func-
tion
*OffOn——O
FunctionDefault settingCustomized setting
Operation buzzer volume5OffO—O1 to 7
Operation signal (Emergency
flashers)OnOffO—O
Time elapsed before automatic
door lock function is activated
if door is not opened after
being unlocked
60 seconds
Off
O—O30 seconds
120 seconds
Open door warning buzzerOffOn——O
Reservation lockOnOff——O
FunctionDefault settingCustomized setting
Smart access system with
push-button startOnOff——O
ABC
ABC
ABC

4888-2. Customization
■PCS (Pre-Collision System) (P.220)
■LTA (Lane Tracing Assist) ( P.227)
■RSA (Road Sign Assist)* ( P.236)
*:If equipped
FunctionDefault settingCustomized setting
PCS (Pre-Collision System)OnOff—O—
Adjust alert timingMiddleEarly—O—Late
FunctionDefault settingCustomized setting
Lane centering functionOnOff—O—
Steering assist functionOnOff—O—
Alert typeSteering wheel
vibrationBuzzer—O—
Alert sensitivityHighStandard—O—
Vehicle sway warning functionOnOff—O—
Vehicle sway warning sensitiv-
ityStandardHigh—O—Low
FunctionDefault settingCustomized setting
RSA (Road Sign Assist)OnOff—O—
Excess speed notification
methodDisplay onlyNo notification—O—Display and buzzer
Excess speed notification level1 mph (2 km/h)3 mph (5 km/h)—O—5 mph (10 km/h)
Other notifications method
(No-entry notification)Display onlyNo notification—O—Display and buzzer
ABC
ABC
ABC

4938-3. Initialization
8
Vehicle specifications
8-3.Initialization
*:If equipped
Items to initialize
The following items must be initialized for normal system operation after such
cases as the 12-volt battery being re connected, or maintenance being per-
formed on the vehicle:
List of items to initialize
ItemWhen to initializeReference
Message indicating
maintenance is
required (U.S.A. only)
• After the maintenance is performedP.362
Tire pressure warning
system
• When changing the tire inflation pres- sure by changing traveling speed
• When changing the tire size
• When rotating the tires
P.385
Oil maintenance• After the maintenance is performedP.373
PKSB (Parking Support
Brake)
*• After reconnecting or changing the 12-volt batteryP.270
Power back door• After reconnecting or changing the 12-volt batteryP.119