maintenance LEXUS RX450h 2021 Service Manual

3876-3. Do-it-yourself maintenance
6
Maintenance and care
However, in the following situations, the tire
inflation pressure will not be recorded and
the system will not operate properly. Per-
form initialization again.
●When operating the tire pressure warn-
ing reset switch, the tire pressure warning
light does not blink 3 times.
●After performing init ialization, the tire
pressure warning light blinks for 1 minute
then stays on while driving.
If the inflation pressure of each tire is still not
displayed, have the vehicle inspected by
your Lexus dealer.
The tire pressure warning valve and
transmitter is equipped with a unique
ID code. When replacing a tire pres-
sure warning valve and transmitter, it is
necessary to register the ID code.
Have the ID code registered by your
Lexus dealer. The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
(
P.460)
Tire valve
Tire pressure gauge
WARNING
■When initializing the tire pressure
warning system
Do not initializing tire inflation pressure
without first adjusting the tire inflation
pressure to the spec ified level. Other-
wise, the tire pressure warning light may
not come on even if the tire inflation pres-
sure is low, or it may come on when the
tire inflation pressure is actually normal.
Registering ID codes
Tire inflation pressure
Checking the specified tire infla-
tion pressure
Inspection and adjustment pro-
cedure
A
B

3886-3. Do-it-yourself maintenance
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.

3896-3. Do-it-yourself maintenance
6
Maintenance and care
When replacing wheels, care should
be taken to ensure that they are equiv-
alent to those removed in load capac-
ity, diameter, rim width and inset
*.
Replacement wheels are available at
your Lexus dealer.
*: Conventionally referred to as offset.
Lexus does not recommend using the
following:
 Wheels of different sizes or types
 Used wheels
 Bent wheels that have been straight-
ened
■When replacing wheels
The wheels of your vehicle are equipped
with tire pressure warning valves and trans-
mitters that allow the tire pressure warning
system to provide advance warning in the
event of a loss in tire inflation pressure.
Whenever wheels are replaced, tire pres-
sure warning valves an d transmitters must
be installed. ( P.384) Use only Lexus wheel nuts and
wrenches designed for use with
your aluminum wheels.
 When rotating, repairing or chang-
ing your tires, check that the wheel
nuts are still tight after driving 1000
miles (1600 km).
 Be careful not to damage the alumi-
num wheels when using tire chains.
 Use only Lexus genuine balance
weights or equivalent and a plastic
or rubber hammer when balancing
your wheels.
Wheels
If a wheel is bent, cracked or heavily
corroded, it should be replaced.
Otherwise, the tire may separate
from the wheel or cause a loss of
handling control.
Wheel selection
WARNING
■When replacing wheels
●Do not use wheels that are a different
size from those recommended in the
Owner’s Manual, as this may result in a
loss of handling control.
●Never use an inner tube in a leaking
wheel which is designed for a tubeless
tire.
Doing so may result in an accident,
causing death or serious injury.
■Use of defective wheels prohibited
Do not use cracked or deformed wheels.
Doing so could cause the tire to leak air
during driving, possibly causing an acci-
dent.
NOTICE
■Replacing tire pressure warning
valves and transmitters
●Because tire repair or replacement
may affect the tire pressure warning
valves and transmitters, make sure to
have tires serviced by your Lexus
dealer or other qua lified service shop.
In addition, make sure to purchase
your tire pressure warning valves and
transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wheels
are used on your vehicle.
Tire pressure warning valves and trans-
mitters may not work properly with
non-genuine wheels.
Aluminum wheel precautions

3906-3. Do-it-yourself maintenance
1Turn the power switch off.
2 Open the glove box. Slide off the
damper.
3 Push in the glove box on the vehi-
cle’s outer side to disconnect the
claws. Then pull out the glove box
and disconnect the lower claws. 4
Remove the cover.
5 Unlock the filter cover ( ), pull the
filter cover out of the claws ( ),
and remove the filter cover.
6 Remove the filter case.
There may be foreign objects on top of the
air conditioning filter.
7Remove the air conditioning filter
from the filter case and replace it
with a new one.
The “ UP” marks shown on the filter
Air conditioning filter
The air conditioning filter must be
changed regularly to maintain air
conditioning efficiency.
Removing the air conditioning
filter
A
B

3916-3. Do-it-yourself maintenance
6
Maintenance and care
and the filter case should be pointing up.
■Checking interval
Inspect and replace the air conditioning fil-
ter according to the maintenance schedule.
In dusty areas or area s with heavy traffic
flow, early replacement may be required.
(For scheduled mainte nance information,
please refer to the “Owner’s Manual Sup-
plement” or “Scheduled Maintenance”.)
■If air flow from th e vents decreases dra-
matically
The filter may be clogged. Check the filter
and replace if necessary.
■Air conditioning filter with deodorizing
function
When fragrances are placed in your vehi-
cle, the deodorizing effect may become
significantly weakened in a short period.
When an air conditioning odor comes out
continuously, replace the air conditioning
filter.
NOTICE
■When using the air conditioning sys-
tem
Make sure that a filter is always installed.
Using the air conditioning system without
a filter may cause damage to the system.
■To prevent damage to the filter cover
When moving the filter cover in the
direction of arrow to release the fitting,
pay attention not to apply excessive force
to the claws. Otherwise, the claws may
be damaged.

3926-3. Do-it-yourself maintenance
1Change the rest position of the
windshield wipers to the service
position using the wiper lever and
then lift a windshield wiper.
(P.209)
2 While pressing and holding the
wiper blade lock release button,
remove the wiper blade.
When performing this operation, make
sure to hold the hook portion of the wiper
arm securely.
Hook portion
3 While disengaging the cap lock,
using a tool such as a flathead
screwdriver if necessary, remove
the wiper insert.
Hold the cap on the end of the wiper insert
when removing the wi per insert. (The cap
is integrated into the wiper insert.)
If using a screwdriver, make sure to wrap its tip with tape to protect the wiper blade.
Cap lock
4 Install a new wiper insert.
Make sure to push the wiper insert firmly
until the cap lock is engaged.
After installation, check that the cap lock is
locked securely.
5Install the wiper blade to the wiper
arm.
Make sure to push the wiper blade until it is
locked.
When performing this operation, make
sure to hold the hook portion of the wiper
arm securely.
After installation, check that the wiper
blade is locked securely.
6 After replacing the wiper inserts,
place the windshield wipers on the
windshield and lower them to the
retracted position. ( P.209)
Do not drive the vehicle with the wind-
shield wipers lifted.
Windshield wiper inserts
Replacing a windshield wiper
insert
A
A

3936-3. Do-it-yourself maintenance
6
Maintenance and care
■Replacing the rear wiper insert
Have the rear wiper inse rt replaced by your
Lexus dealer.
■Handling of the windshield wiper blades
and inserts
Improper handling of the windshield wiper
blades and inserts may cause them to be
damaged. If it is difficult to follow the wiper
blade and insert replacement procedure
precisely, contact your Lexus dealer.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-but-
ton start and wireless remote control will
not function properly.
●The operationa l range will be reduced.
Flathead screwdriver
 Lithium battery CR2032
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus
dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent
type recommended by the manufacturer.
●Dispose of used batteries according to
the local laws.
1Take out the mechanical key.
2 Remove the cover.
To prevent damage to the key, cover the tip
Electronic key battery
Replace the battery with a new one
if it is depleted.
You will need the following items:
Replacing the battery

3946-3. Do-it-yourself maintenance
of the flathead screwdriver with a tape.
3Remove the depleted battery.
When removing the cover, the electronic
key module may stick to the cover and the
battery may not be visible. In this case,
remove the electronic key module in order
to remove the battery.
Insert a new battery with the “+” terminal
facing up.
WARNING
■Battery precautions
Observe the following precautions.
Failure to do so may result in death or
serious injury.
●Do not swallow the battery. Doing so
may cause chemical burns.
●A coin battery or button battery is
used in the electronic key. If a battery is
swallowed, it may cause severe chemi-
cal burns in as little as 2 hours and may
result in death or serious injury.
●Keep away new and removed batteries
from children.
●If the cover cannot be firmly closed,
stop using the electronic key and stow
the key in the place where children
cannot reach, and then contact your
Lexus dealer.
●If you accidentally swallow a battery or
put a battery into a part of your body,
get emergency medical attention
immediately.
■To prevent battery explosion or leak-
age of flammable liquid or gas
●Replace the battery with a new battery
of the same type. If a wrong type of
battery is used, it may explode.
●Do not expose batteries to extremely
low pressure due to high altitude or
extremely high temperatures.
●Do not burn, break or cut a battery.
NOTICE
■For normal operation after replacing
the battery
Observe the following precautions to
prevent accidents:
●Always work with dry hands.
Moisture may cause the battery to
rust.
●Do not touch or move any other com-
ponent inside the remote control.
●Do not bend either of the battery ter-
minals.

3956-3. Do-it-yourself maintenance
6
Maintenance and care
1Turn the power switch off.
2 Open the fuse box cover.
Engine compartment
Push the tab in and lift the lid off.
Driver’s side instrument panel
Remove the lid.
Luggage compartment (type A fuse
box)
RX450h:
Remove the 12-volt battery cover.
( P.376) RX450hL:
Remove the deck board and side auxiliary
box cover and 12-volt battery cover.
(
 P.376)
Luggage compartment (type B fuse
box)
RX450h:
Remove the terminal cover.
RX450hL:
Remove the terminal cover.
Checking and replacing
fuses
If any of the electrical components
do not operate, a fuse may have
blown. If this happens, check and
replace the fuses as necessary.
Checking and replacing fuses

3966-3. Do-it-yourself maintenance
3Remove the fuse with the pullout
tool.
Only some fuses can be removed
using the pullout tool.
4 Check if the fuse is blown.
Normal fuse
Blown fuse
Replace the blown fuse with a new fuse of
an appropriate amperage rating. The
amperage rating can be found on the fuse
box lid.
Many types of fuse are used on this vehicle.
This illustration shows a common type of
fuse used on this vehicle.
■After a fuse is replaced
●If the lights do not turn on even after the
fuse has been replaced, a bulb may need
replacement. ( P.399)
●If the replaced fuse blows again, have the
vehicle inspected by your Lexus dealer.
■If there is an overload in a circuit
The fuses are designed to blow, protecting
the wiring harness from damage.
■When replacing light bulbs
Lexus recommends that you use genuine
Lexus products designed for this vehicle.
Because certain bulbs are connected to cir-
cuits designed to prevent overload,
non-genuine parts or parts not designed for
this vehicle may be unusable.
A
B
WARNING
■To prevent system breakdowns and
vehicle fire
Observe the following precautions.
Failure to do so may cause damage to
the vehicle, and possibly a fire or injury.
●Never use a fuse of a higher amperage
rating than that indicated, or use any
other object in place of a fuse.
●Always use a genuine Lexus fuse or
equivalent.
Never replace a fuse with a wire, even
as a temporary fix.
●Do not modify the fuses or fuse boxes.
■Fuse box near the power control unit
Never check or replace the fuses as
there are high voltage parts and wiring
near the fuse box.
Doing so may cause electric shock,
resulting in death or serious injury.