2021 LEXUS RX450h service

3666-2. 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

3676-3. Do-it-yourself maintenance
6
Maintenance and care
6-3.Do-it-yourself maintenance
Do-it-yourself service pre-
cautions
If you perform maintenance by
yourself, be sure to follow the cor-
rect procedure as given in these
sections.
Maintenance
ItemsParts and tools
12-volt battery
condition
( P.376)•Grease
• Conventional
wrench (for terminal
clamp bolts)
Brake fluid level
( P.375)
• FMVSS No.116 DOT
3 or SAE J1703
brake fluid
•Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/power
control unit cool-
ant level
( P.373)
•“Toyota Super Long
Life Coolant” or a
similar high quality
ethylene gly-
col-based non-sili-
cate, non-amine,
non-nitrite and
non-borate coolant
with long-life hybrid
organic acid tech-
nology
For the U.S.A.:
“Toyota Super Long
Life Coolant” is
pre-mixed with 50%
coolant and 50%
deionized water.
For Canada:
“Toyota Super Long
Life Coolant” is
pre-mixed with 55%
coolant and 45%
deionized water.
•Funnel (used only for adding coolant)
Engine oil level
( P.371)
•“Toyota Genuine
Motor Oil” or equiv-
alent
• Rag or paper towel
•Funnel (used only for adding engine oil)
Fuses ( P.395)
•Fuse with same
amperage rating as
original
Headlight aim
( P.397)• Phillips-head screw-
driver
ItemsParts and tools

3736-3. Do-it-yourself maintenance
6
Maintenance and care
●When the engine is new, for example
directly after purchasing the vehicle or
after replacing the engine
●If low quality oil or oil of an inappropriate
viscosity is used
●When driving at high engine speeds or
with a heavy load, when towing, or when
driving while accelera ting or decelerat-
ing frequently
●When leaving the engine idling for a long
time, or when driving frequently through
heavy traffic
■After changing the engine oil
The engine oil maintena nce data should be
reset. Perform the following procedures:
1 Press or of the meter control
switch to select on the multi-infor-
mation display.
2 Press or of the meter control
switch, select the “Vehicle Settings”
then “Oil Maintenance”. (To confirm
setting, press .)
3 Select the “Yes” and press .
4 A message is displayed on the
multi-information display.
■Engine coolant reservoir
The coolant level is satisfactory if it is
between the “FULL” and “LOW” lines
on the reservoir when the hybrid sys-
tem is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
( P.454)
WARNING
■Used engine oil
●Used engine oil contains potentially
harmful contaminants which may
cause skin disorders such as inflamma-
tion and skin cancer, so care should be
taken to avoid prolonged and
repeated contact. To remove used
engine oil from your skin, wash thor-
oughly with soap and water.
●Dispose of used oil and filters only in a
safe and acceptable manner. Do not
dispose of used oil and filters in house-
hold trash, in sewers or onto the
ground.
Call your Lexus dealer, service station
or auto parts store for information
concerning recycling or disposal.
●Do not leave used engine oil within the
reach of children.
NOTICE
■To prevent serious engine damage
Check the oil level on a regular basis.
■When replacing the engine oil
●Be careful not to spill engine oil on the
vehicle components.
●Avoid overfilling, or the engine could
be damaged.
●Check the oil level on the dipstick
every time you re fill the vehicle.
●Be sure the engine o il filler cap is prop-
erly tightened.
Checking the coolant
A
B
C

3856-3. Do-it-yourself maintenance
6
Maintenance and care
( P.387)
■Replacing tires and wheels
If the ID code of the tire pressure warning
valve and transmitter is not registered, the
tire pressure warning system will not work
properly. After driving for about 20 min-
utes, the tire pressure warning light blinks
for 1 minute and stays on to indicate a sys-
tem malfunction.
■The tire pressure warning system
must be initialized in the following
circumstances:
 When the tire inflation pressure is
changed such as when changing
traveling speed.
 When the tire inflation pressure is
changed such as when the tire size
is changed.
 When rotating the tires.
When the tire pressure warning system
is initialized, the current tire inflation
pressure is set as the benchmark pres-
sure.
■How to initialize the tire pressure
warning system
1 Park the vehicle in a safe place and
turn the power switch off.
Initialization cannot be performed while
the vehicle is moving.
2 Adjust the tire inflation pressure to
the specified cold tire inflation pres-
sure level.
Make sure to adjust the tire pressure to the
specified cold tire infl ation pressure level.
The tire pressure warning system will oper-
ate based on this pressure level.
3 Turn the power switch to ON
mode.
4 Select on the multi-information
display.
5 Press or of the meter con-
trol switch, select the “Vehicle Set-
NOTICE
■Repairing or replacing tires, wheels,
tire pressure warning valves, trans-
mitters and tire valve caps
●When removing or fitting the wheels,
tires or the tire pressure warning
valves and transmitters, contact your
Lexus dealer as the tire pressure warn-
ing valves and transmitters may be
damaged if not handled correctly.
●Make sure to install the tire valve caps.
If the tire valve caps are not installed,
water could enter the tire pressure
warning valves and the tire pressure
warning valves could be bound.
●When replacing tire valve caps, do not
use tire valve caps other than those
specified. The cap may become stuck.
■To avoid damage to the tire pressure
warning valves and transmitters
When a tire is repaired with liquid seal-
ants, the tire pressu re warning valve and
transmitter may not operate properly. If a
liquid sealant is used , contact your Lexus
dealer or other qualified service shop as
soon as possible. Make sure to replace
the tire pressure warning valve and trans-
mitter when replacing the tire. ( P.384)
Initializing the tire pressure
warning system

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

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

4137-2. Steps to take in an emergency
7
When trouble arises
7-2.Steps to take in an emergency
If your vehicle needs to be
towed
If towing is necessary, we recom-
mend having your vehicle towed by
your Lexus dealer or commercial
towing service, using a wheel-lift
type truck or flatbed truck.
Use a safety chain system for all
towing, and abide by all state/pro-
vincial and local laws.
If towing your vehicle with a
wheel-lift type truck, use a towing
dolly. ( P.414, 413)
WARNING
Observe the following precautions.Fail-
ure to do so may result in death or seri-
ous injury.
■When towing the vehicle
Be sure to transport the vehicle with all
four wheels raised off the ground. If the
vehicle is towed with the tires contacting
the ground, the driv etrain or related
parts may be damaged, the vehicle may
fly off the truck, or electricity generated
by the operation of the motor may cause
a fire to occur depending on the nature
of the damage or malfunction.
■While towing
●When towing using cables or chains,
avoid sudden starts, etc. which place
excessive stress on the towing eyelets,
cables or chains. The towing eyelets,
cables or chains may become dam-
aged, broken debris may hit people,
and cause serious damage.
●Do not turn the power switch off.
There is a possibility that the steering
wheel is locked and cannot be oper-
ated.
■Installing towing eyelets to the vehi-
cle
Make sure that towing eyelets are
installed securely.If no t securely installed,
towing eyelets may come loose during
towing.

4147-2. Steps to take in an emergency
The following may indicate a problem
with your transmission. Contact your
Lexus dealer or commercial towing service before towing.

The hybrid system warning message
is shown on the multi-information
display and the vehicle does not
move.
 The vehicle makes an abnormal
sound.
From the front
Use a towing dolly under the rear
wheels.
From the rear
Use a towing dolly under the front
wheels.
NOTICE
■To prevent damage to the vehicle
when towing using a wheel-lift type
truck
●Do not tow the vehicle from the rear
when the power switch is off. The
steering lock mechanism is not strong
enough to hold the front wheels
straight.
●When raising the vehicle, ensure ade-
quate ground clearance for towing at
the opposite end of the raised vehicle.
Without adequate clearance, the vehi-
cle could be damaged while being
towed.
■To prevent damage to the vehicle
when towing with a sling-type truck
Do not tow with a sling-type truck, either
from the front or rear.
■To prevent damage to the vehicle
during emergency towing
Do not secure cables or chains to the
suspension components.
■Recreational towing (behind motor
home, etc.)
Never dinghy tow your vehicle to pre-
vent causing serious damage to the
Hybrid AWD system and transmission.
(  P.183)
Situations when it is necessary to
contact dealers before towing
Towing with a wheel-lift type
truck