Fuel LEXUS RX450h 2022 Service Manual

3065-3. Using the air conditioning system and defogger
If the fan speed setting or air flow modes
are operated, the automatic mode indica-
tor goes off. However, automatic mode for
functions other than that operated is main-
tained.
■Using automatic mode
Fan speed is adjusted automatically accord-
ing to the temperature setting and the
ambient conditions.
Therefore, the fan may stop for a while until
warm or cool air is ready to flow immedi-
ately after the automatic mode switch is
pressed or “AUTO” is selected.
Cool air may blow ar ound the upper body
even when the heater is on due to sunlight.
■Automatic mode for air intake control (if
equipped)
In automatic mode, the system detects
exhaust gas and other pollutants and auto-
matically switches between outside air and
recirculated air modes.
When the dehumidificati on function is off,
and the fan is operating, turning automatic
mode on will activate the dehumidification
function.
This function automatically controls the
air conditioning airflo w so that priority
is given to the front seats. When the
front passenger seat is not occupied,
airflow may switch to only the driver's
seat. Unnecessary air conditioning is
suppressed, contributing to increased
fuel efficiency.
Front seat concentrated airflow mode
operates in the following situations.
 No passengers are detected in the
rear seats
 The windshield defogger is not
operating
While operating, illuminates.
■Manually turning front seat con-
centrated airflow mode on/off
In front seat concentrated airflow
mode, directing airflow to the front
seats only and to all seats can be
switched via switch operation. When
the mode has been switched manually,
automatic airflow control stops operat-
ing.
NOTICE
■Humidity sensor
In order to detect fo g on the windshield,
a sensor which monitors the temperature
of the windshield, the surround humidity,
etc. is installed.
Follow these points to avoid damaging
the sensor:
●Do not disassemb le the sensor
●Do not spray glass cleaner on the sen-
sor or subject it to strong impacts
●Do not stick anything on the sensor
Front seat concentrated airflow
mode (S-FLOW)

3566-2. Maintenance
6-2.Maintenance
■Repair and replacement
It is recommended that genuine Lexus parts
be used for repairs to ensure performance
of each system. If non-Lexus parts are used
in replacement or if a repair shop other than
a Lexus dealer performs repairs, confirm
the warranty coverage.
■Allow inspection and repairs to be per-
formed by a Lexus dealer
●Lexus technicians are well-trained spe-
cialists and are kept up to date with the
latest service information. They are well
informed about the operation of all sys-
tems on your vehicle.
●Keep a copy of the repair order. It proves
that the maintenance that has been per-
formed is under warra nty coverage. If any
problem should arise while your vehicle is
under warranty, your Lexus dealer will
promptly take care of it.
General maintenance should be per-
formed on a daily basis. This can be
done by yourself or by a Lexus dealer.
Scheduled maintenance should be
performed at specified intervals
according to the maintenance sched-
ule.
For details about ma intenance items and
schedules, refer to the “Warranty and Ser-
vice Guide”, “Owner’s Manual Supple-
ment” or “Scheduled Maintenance”.
■Resetting the message indicating main-
tenance is required (U.S.A. only)
After the required maintenance is pre-
formed according to the maintenance
schedule, please reset the message.
To reset the message, follow the procedures
described below:
1 Press or of the meter control
switch to select .
2 Press or of the meter control
switch, select the “Scheduled Mainte-
nance” screen and then press and hold
the .
Maintenance requirements
To ensure safe and economical driv-
ing, day-to-day care and regular
maintenance are essential. It is the
owner’s responsibility to perform
regular checks. Lexus recommends
the following maintenance:
WARNING
■If your vehicle is not properly main-
tained
Improper maintenance could result in
serious damage to the vehicle and possi-
ble death or serious injury.
■Handling of the 12-volt battery
●Engine exhaust, some of its constitu-
ents, and a wide variety of automobile
components contain or emit chemicals
known to the State of California to
cause cancer and birth defects and
other reproductive harm. Work in a
well ventilated area.
●Oils, fuels and fluids contained in vehi-
cles as well as waste produced by
component wear contain or emit
chemicals known to the State of Cali-
fornia to cause cancer and birth
defects or other re productive harm.
Avoid exposure and wash any affected
area immediately.
●12-volt battery post s, terminals and
related accessories contain lead and
lead compounds which are known to
cause brain damage. Wash your hands
after handling. ( P.370)
General maintenance
Scheduled maintenance

3606-2. Maintenance
The OBD system determines that a
problem exists somewhere in the emis-
sion control system. Your vehicle may
not pass the I/M test and may need to
be repaired. Contact your Lexus
dealer to service the vehicle.
When the 12-volt battery is discon-
nected or discharged
Readiness codes that are set during ordi-
nary driving are erased.
Also, depending on your driving habits, the
readiness codes may not be completely
set.
 When the fuel tank cap is loose
The malfunction indicator lamp comes on
indicating a temporary malfunction and
your vehicle may not pass the I/M test.
The error code in the OBD system will
not be cleared unless the vehicle is
driven 40 or more times.
Contact your Lexus dealer to prepare
the vehicle for re-testing.
Emission inspection and
maintenance (I/M) pro-
grams
Some states have vehicle emission
inspection programs which include
OBD (On Board Diagnostics)
checks. The OBD system monitors
the operation of the emission con-
trol system.
If the malfunction indicator lamp
comes on
Your vehicle may not pass the
I/M test in the following situa-
tions:
When the malfunction indicator
lamp still remains on after sev-
eral driving trips
If your vehicle does not pass the
I/M test

3626-3. Do-it-yourself maintenance
Light bulbs
(P.392)
•Bulb with same num-
ber and wattage rat-
ing as original
•Flathead screw- driver
•Wrench
Radiator and con-
denser ( P.368)
Tire inflation pres-
sure ( P.380)• Tire pressure gauge
•Compressed air
source
Washer fluid
(P.369)
• Water or washer
fluid containing anti-
freeze (for winter
use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Make sure that the “ACCESSORY” or
“IGNITION ON” on the multi-infor-
mation display and the “READY” indi-
cator are both off.
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
power control unit, radiator, exhaust
manifold, etc. right after driving as they
may be hot. Oil and other fluids may
also be hot.
ItemsParts and tools●Do not leave anything that may burn
easily, such as paper and rags, in the
engine compartment.
●Do not smoke, cause sparks or expose
an open flame to fuel. Fuel fumes are
flammable.
■When working near the electric cool-
ing fan or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the
electric cooling fans may automatically
start to run if the air conditioning is on
and/or the coolant temperature is high.
(  P.368)
■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

3816-3. Do-it-yourself maintenance
6
Maintenance and care
1Remove the tire valve cap.
2 Press the tip of the tire pressure
gauge onto the tire valve.
3 Read the pressure using the gauge
gradations.
4 If the tire inflation pressure is not at
the recommended level, adjust the
pressure.
If you add too much air, press the
center of the valve to deflate.
5 After completing the tire inflation
pressure measurem ent and adjust-
ment, apply soapy water to the
valve and check for leakage.
6 Put the tire valve cap back on.
■Tire inflation pressure check interval
You should check tire inflation pressure
every two weeks, or at least once a month.
Do not forget to check the spare.
■Effects of incorrect tire inflation pres-
sure
Driving with incorrect ti re inflation pressure
may result in the following:
●Reduced fuel economy
●Reduced driving comfort and poor han-
dling
●Reduced tire life due to wear
●Reduced safety
●Damage to the drive train
If a tire needs frequent inflating, have it
checked by your Lexus dealer.
■Instructions for checking tire inflation
pressure
When checking tire inflation pressure,
observe the following:
●Check only when the tires are cold.
If your vehicle has been parked for at
least 3 hours or has not been driven for
more than 1 mile or 1.5 km, you will get an
accurate cold tire in flation pressure read- ing.
●Always use a tire pressure gauge.
It is difficult to judge if a tire is properly
inflated based only on its appearance.
●It is normal for the ti
re inflation pressure
to be higher after driving as heat is gen-
erated in the tire. Do not reduce tire infla-
tion pressure after driving.
●Never exceed the vehicle capacity
weight.
Passengers and luggage weight should
be placed so that the vehicle is balanced.
WARNING
■Proper inflation is critical to save tire
performance
Keep your tires properly inflated.
If the tires are not properly inflated, the
following conditions may occur which
could lead to an accident resulting in
death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from
overheated tires
●Air leaking from between tire and
wheel
●Wheel deformation and/or tire dam-
age
●Greater possibility of tire damage
while driving (due to road hazards,
expansion joints, sharp edges in the
road, etc.)
NOTICE
■When inspecting and adjusting tire
inflation pressure
Be sure to put the tire valve caps back on.
If a valve cap is not installed, dirt or mois-
ture may get into the valve and cause an
air leak, resulting in decreased tire infla-
tion pressure.

401
7
7
When trouble arises
When trouble arises
.7-1. Essential informationEmergency flashers.................. 402
If your vehicle has to be stopped in an emergency .......................... 402
If the vehicle is submerged or water on the road is rising
........................................................ 403
7-2. Steps to take in an emergency If your vehicle needs to be towed........................................................ 405
If you think something is wrong ........................................................ 409
If a warning light turns on or a warning buzzer sounds ........ 410
If a warning message is displayed ........................................................ 420
If you have a flat tire.................. 424
If the hybrid syst em will not start
........................................................ 436
If you lose your keys ................. 438
If the fuel filler door cannot be opened........................................ 438
If the electronic key does not operate properly .................... 439
If the 12-volt battery is discharged ......................................................... 441
If your vehicle overheats ........ 446
If the vehicle becomes stuck ........................................................ 449

4137-2. Steps to take in an emergency
7
When trouble arises
■Electric power steering system warning light (warning buzzer)
■Low fuel level warning light
■Driver’s and front passenger’s seat belt reminder light (warning buzzer)*
*: Driver’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to alert the driver that his or her seat belt is not
fastened. Once the power switch is turned to ON mode, the buzzer sounds. If the seat belt
is still unfastened, the buzzer sounds intermittently for a cert ain period of time after the
vehicle reaches a certain speed.
Front passenger’s seat belt warning buzzer:
The front passenger’s seat belt warning buzzer sounds to alert the front passenger that his
or her seat belt is not fastened. If the seat belt is unfastened, the buzzer sounds intermit-
tently for a certain period of time af ter the vehicle reaches a certain speed.
Warning lightDetails/Actions
(red)
or
(yellow)
Indicates a malfunction in the EPS (Electric Power Steering) system
Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
Indicates that remaining fu el is approximately 2.9 gal. (11.0 L, 2.4 Imp.
gal.) or less
 Refuel the vehicle.
Warning lightDetails/Actions
Warns the driver and/or front passenger to fasten their seat belts
Fasten the seat belt.
If the front passenger’s seat is occupied, the front passenger’s seat
belt also needs to be fastened to make the warning light (warning
buzzer) turn off.

4177-2. Steps to take in an emergency
7
When trouble arises
■Brake hold operated indicator
■Master warning light
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause the warning light to
flash and the warning buzzer to sound
even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■SRS warning light
This warning light sy stem monitors the
airbag sensor assembly, front impact sen-
sors, side impact sensors (front door), side
impact sensors (rear), driver’s seat position
sensor, driver’s seat be lt buckle switch, front
passenger occupant cl assification system
(ECU and sensors), “AIR BAG ON” indica-
tor light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch,
driver’s seat belt pretensioner, front passen-
ger’s seat belt pretensioner and force lim-
iter, airbags, interconnecting wiring and
power sources. ( P.30)
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving
trips.
If the light does not go off even after several
trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning
light (warning buzzer)
When the 12-volt battery charge becomes
insufficient or the voltage temporarily
drops, the electric power steering system
warning light may come on and the warning
buzzer may sound.
■When the tire pressure warning light
comes on
Inspect the tires to check if a tire is punc-
tured.
If a tire is punctured: P.424
If none of the tires are punctured:
Turn the power switch off then turn it to ON
mode. Check if the tire pressure warning
light comes on or blinks.
If the tire pressure warning light blinks for
1 minute then stays on
There may be a malfunction in the tire
pressure warning system. Have the vehicle
inspected by your Lexus dealer immedi-
ately.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
A buzzer sounds and the warning light comes on and flashes to indicate
that the master warning system has detected a malfunction.
P.420

4197-2. Steps to take in an emergency
7
When trouble arises
WARNING
■If a blowout or sudden air leakage
should occur
The tire pressure warning system may
not activate immediately.
■Maintenance of the tires
Each tire, including the spare (if pro-
vided), should be checked monthly when
cold and inflated to the inflation pressure
recommended by the vehicle manufac-
turer on the vehicle placard or tire infla-
tion pressure label (tire and load
information label). (If your vehicle has
tires of a different size than the size indi-
cated on the vehicle placard or tire infla-
tion pressure label [tire and load
information label], you should determine
the proper tire infl ation pressure for
those tires.)
As an added safety feature, your vehicle
has been equipped with a tire pressure
monitoring system (TPMS-tire pressure
warning system) that illuminates a low
tire pressure telltale (tire pressure warn-
ing light) when one or more of your tires
is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale
(tire pressure warning light) illuminates,
you should stop and check your tires as
soon as possible, and inflate them to the
proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire
to overheat and can lead to tire failure.
Under-inflation also reduces fuel effi-
ciency and tire tread life, and may affect
the vehicle’s handling and stopping abil-
ity.
Please note that the TPMS (tire pressure
warning system) is not a substitute for
proper tire maintena nce, and it is the
driver’s responsibility to maintain correct
tire pressure, even if under-inflation has
not reached the level to trigger illumina-
tion of the TPMS low tire pressure telltale
(tire pressure warning light).
Your vehicle has also been equipped with
a TPMS (tire pressure warning system)
malfunction indicator to indicate when
the system is not operating properly. The
TPMS (tire pressure warning system)
malfunction indicator is combined with
the low tire pressure telltale (tire pres-
sure warning light) . When the system
detects a malfunction, the telltale will
flash for approximately one minute and
then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the
malfunction exists. When the malfunction
indicator is illuminated, the system may
not be able to detect or signal low tire
pressure as intended.
TPMS (tire pressure warning system)
malfunctions may occur for a variety of
reasons, including the installation of
replacement or alternate tires or wheels
on the vehicle that prevent the TPMS
(tire pressure warning system) from func-
tioning properly. Always check the
TPMS (tire pressure warning system)
malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate
tires and wheels allow the TPMS (tire
pressure warning system) to continue to
function properly.
NOTICE
■To ensure the tire pressure warning
system operates properly
Do not install tires with different specifi-
cations or makers, as the tire pressure
warning system may not operate prop-
erly.

4367-2. Steps to take in an emergency
One of the following may be the cause
of the problem:
The electronic key may not be func-
tioning properly. ( P.439)
 There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle.
 There may be a malfunction in the
immobilizer system. ( P.73)
 There may be a malfunction in the
steering lock system.
 The hybrid system may be malfunc-
tioning due to an electrical problem
such as electronic key battery
depletion or a blown fuse. However,
depending on the type of malfunc-
tion, an interim measure is available
to start the hybrid system. ( P.437)
One of the following may be the cause
NOTICE
■Proper storage of the spare tire
(RX450hL)
●If the hoist assembly is slanted when
stowing a tire, the hoist assembly may
become stuck in the wheel opening
and the tire may not be raised properly,
causing damage to the wheel or the
wire cable.
●If the spare tire clamp bolt is turned
without a tire on the hoist assembly, the
wire cable may not be able to be low-
ered. If the wire cable cannot be low-
ered, contact your Lexus dealer.
If the hybrid system will not
start
Reasons for the hybrid system not
starting vary depending on the situ-
ation. Check the following and per-
form the appropriate procedure:
The hybrid system will not start
even though the correct starting
procedure is being followed.
(  P.182)
The interior lights and head-
lights are dim, or the horn does
not sound or sounds at a low vol-
ume.