LEXUS RC300 2021 Owners Manual

2616-3. Do-it-yourself maintenance
6
Maintenance and care
on the reservoir when the engine is
cold.
■Engine coolant reservoir
RC350/RC300 AWD
RC300Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
(  P.322)
■Intercooler coolant reservoir
(RC300)
The coolant level is satisfactory if it is
between the “F” and “L” lines on the
reservoir when the engine is cold. Reservoir cap
“F” line
“L” line
If the level is on or
below the “L” line, add
coolant up to the “F” line. ( P.322)
■Coolant selection
Only use “Toyota Super Long Life Coolant”
or a similar high qua lity ethylene glycol
based non-silicate, non-amine, non-nitrite,
and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mix-
ture of 50% coolant and 50% deionized
water. (Minimum temperature: -31°F
[-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water. (Minimum temperature: -44°F
[-42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radi ator, hoses, engine
and intercooler coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
A
B
C
A
B
C

2626-3. Do-it-yourself maintenance
Check the radiator, condenser and
intercooler radiator and clear away
any foreign objects.
If any of the above parts are extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
RC350/RC300 AWD
RC300
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
SAE J1703 or FMVSS No.116 DOT 3
brake fluid
SAE J1704 or FMVSS No.116 DOT 4
brake fluid
Item
Clean funnel
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir cap, intercooler coolant reservoir
cap and coolant inlet cap. ( P.325)
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct mixture
of water and antifreeze must be used to
provide proper lubrication, corrosion
protection and cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damagi ng parts or paint.
Checking the radiator, con-
denser and intercooler radiator
(if equipped)
WARNING
■When the engine is hot
Do not touch the radiator, condenser or
intercooler radiator as they may be hot
and cause serious injuries, such as burns.
Checking and adding the brake
fluid

2636-3. Do-it-yourself maintenance
6
Maintenance and care
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause
a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
Check the battery as follows.
■Battery exterior
Make sure that the battery terminals
are not corroded and that there are no
loose connections, cracks, or loose
clamps. Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces
hydrogen gas which is flammable and
explosive. Therefore, observe the following
before recharging:
●If recharging with the battery installed on
the vehicle, be sure to disconnect the
ground cable.
●Make sure the power switch on the char-
ger is off when connecting and discon-
necting the charger cables to the battery.
■After recharging/reconnecting the bat-
tery
The engine may not start. Follow the proce-
dure below to initialize the system.
1 Shift the shift lever to P.
2 Open and close either door.
3 Restart the engine.
●Unlocking the doors using the smart
access system with pu sh-button start may
not be possible immediately after recon-
necting the battery. If this happens, use
the wireless remote control or the
mechanical key to lo ck/unlock the doors.
●Start the engine with the engine switch in
ACCESSORY mode. The engine may
not start with the engine switch turned off.
However, the engine will operate nor-
mally from the second attempt.
●The engine switch mode is recorded by
the vehicle. If the battery is disconnected
and reconnected, the vehicle will return
the engine switch mode to the status it
was in before the battery was discon-
nected. Make sure to turn off the engine
before disconnecting the battery. Take
extra care when connecting the battery if
the engine switch mode prior to the bat-
tery being disconnected is unknown.
If the system will not start even after multi-
ple attempts, contact your Lexus dealer.
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.If fluid gets on your hands or in your
eyes, flush the affected area with clean
water immediately.
If you still experience discomfort, see a
doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid level in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Battery
A
B

2646-3. Do-it-yourself maintenance
If any washer does not work or the
warning message appears on the
multi-information display, the washer
tank may be empty. Add washer fluid.
RC350/RC300 AWD
WARNING
■Chemicals in the battery
Batteries contain poisonous and corro-
sive sulfuric acid and may produce
hydrogen gas which is flammable and
explosive. To reduce the risk of death or
serious injury, take the following precau-
tions while working on or near the bat-
tery:
●Do not cause sparks by touching the
battery terminals with tools.
●Do not smoke or light a match near the
battery.
●Avoid contact with eyes, skin and
clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when
working near the battery.
●Keep children away from the battery.
■Where to safely charge the battery
Always charge the battery in an open
area. Do not charge the battery in a
garage or closed room where there is
insufficient ventilation.
■How to recharge the battery
Only perform a slow charge (5 A or
less). The battery may explode if charged
at a quicker rate.
■Emergency measures regarding
electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at
least 15 minutes and get immediate med-
ical attention. If possible, continue to
apply water with a sponge or cloth while
traveling to the nearest medical facility.
●If electrolyte gets on your skin
Wash the affected area thoroughly. If you
feel pain or burning, get medical atten-
tion immediately.
●If electrolyte gets on your clothes
It can soak through clothing on to your
skin. Immediately take off the clothing
and follow the procedure above if neces-
sary.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk.
Get emergency medical attention imme-
diately.
NOTICE
■When recharging the battery
Never recharge the battery while the
engine is running. Also, be sure all acces-
sories are turned off.
Adding the washer fluid

2656-3. Do-it-yourself maintenance
6
Maintenance and care
RC300Check if the treadwear indicators are
showing on the tires. Also check the
tires for uneven wear, such as excessive
wear on one side of the tread.
Check the spare tire condition and
pressure if not rotated.
New tread
Worn tread
Treadwear indicator
The location of treadwear indicators is
shown by a “TWI” or “ ” mark, etc.,
molded into the sidewall of each tire.
Replace the tires if the treadwear indica-
tors are showing on a tire.
WARNING
■When adding washer fluid
Do not add washer fluid when the engine
is hot or running as washer fluid contains
alcohol and may catch fire if spilled on
the engine, etc.
NOTICE
■Do not use any fluid other than
washer fluid
Do not use soapy water or engine anti-
freeze instead of washer fluid.
Doing so may cause streaking on the
vehicle’s painted surfaces, as well as
damaging the pump leading to problems
of the washer fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as neces-
sary.
Refer to the freezing temperatures listed
on the label of the washer fluid bottle.
Tires
Replace or rotate tires in accor-
dance with maintenance schedules
and treadwear.
Checking tires
A
B
C

2666-3. Do-it-yourself maintenance
■When to replace your vehicle’s tires
Tires should be replaced if:
●The treadwear indicators are showing on
a tire.
●You have tire damage such as cuts, splits,
cracks deep enough to expose the fabric,
and bulges indicating internal damage
●A tire goes flat repeatedly or cannot be
properly repaired due to the size or loca-
tion of a cut or other damage
If you are not sure, consult your Lexus
dealer.
■Tire life
Any tire over 6 years old must be checked
by a qualified technician even if it has sel-
dom or never been used or damage is not
obvious.
■Low profile tires
Generally, low profile tires will wear more
rapidly and tire grip performance will be
reduced on snowy and/or icy roads when
compared to standard ti res. Be sure to use
snow tires or tire chains on snowy and/or icy
roads and drive carefully at a speed appro-
priate for road and weather conditions.
■Maximum load of tire
Check that the maximum load of the
replacement tire is greater than 1/2 of the
Gross Axle Weight Ratings (GAWR) of
either the front axle or the rear axle, which-
ever is greater.
For the GAWR, see the Certification Label.
For the maximum load of the tire, see the
load limit at maximum cold tire inflation
pressure mentioned on the sidewall of the
tire. ( P.341)
■Tire types
●Summer tires Summer tires are high-speed performance
tires best suited to
highway driving under
dry conditions. Since summer tires do not
have the same traction performance as
snow tires, summer ti res are inadequate for
driving on snow-covered or icy roads. For
driving on snow-covered roads or icy
roads, the use of snow tires is recom-
mended. When installing snow tires, be
sure to replace all four tires.
●All season tires
All season tires are designed to provide
better traction in snow and to be adequate
for driving in most winter conditions as well
as for use year-round. All season tires,
however, do not have adequate traction
performance compared with snow tires in
heavy or loose snow. Also, all season tires
fall short in accelerati on and handling per-
formance compared with summer tires in
highway driving.
●Snow tires
For driving on snow-covered roads or icy
roads, we recommend using snow tires. If
you need snow tires, select tires of the
same size, construction and load capacity
as the originally instal led tires. Since your
vehicle has radial tires as original equip-
ment, make sure your snow tires also have
radial construction. Do not install studded
tires without first checking local regula-
tions for possible restrictions. Snow tires
should be installed on all wheels.
(  P.205)
■If the tread on snow tires wears down
below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is
lost.

2676-3. Do-it-yourself maintenance
6
Maintenance and care
Vehicles with front and rear tires of
the same size
Rotate the tires in the order shown.
To equalize tire wear and extend tire life,
Lexus recommends that tire rotation is car-
ried out at the same in terval as tire inspec-
tion.
Do not fail to initialize the tire pressure
warning system after tire rotation.
Vehicles with front and rear tires of
differing sizes
Tires cannot be rotated.
■When rotating the tires
Make sure that the engine switch is off. If the
tires are rotated while the engine switch is in
IGNITION ON mode, the tire position
WARNING
■When inspecting or replacing tires
Observe the following precautions to
prevent accidents.
Failure to do so may cause damage to
parts of the drivetrain as well as danger-
ous handling characteristics, which may
lead to an accident resulting in death or
serious injury.
●Do not mix tires of different makes,
models or tread patterns.
Also, do not mix tires of remarkably
different treadwear.
●Do not use tire sizes other than those
recommended by Lexus.
●Do not mix differently constructed
tires (radial, bias-b elted or bias-ply
tires).
●Do not mix summer, all season and
snow tires.
●Do not use tires that have been used
on another vehicle.
Do not use tires if you do not know
how they were used previously.
●Do not tow if your vehicle has a com-
pact spare tire installed.
NOTICE
■Low profile tires
Low profile tires may cause greater dam-
age than usual to the tire wheel when
sustaining impact from the road surface.
Therefore, pay attention to the following:
●Be sure to use proper tire inflation
pressure. If tires are under-inflated,
they may be damaged more severely.
●Avoid potholes, uneven pavement,
curbs and other road hazards. Failure
to do so may lead to severe tire and
wheel damage.
■If tire inflation pressure of each tire
becomes low while driving
Do not continue driving, or your tires
and/or wheels may be ruined.
■Driving on rough roads
Take particular care when driving on
roads with loose surfaces or potholes.
These conditions may cause losses in tire
inflation pressure, reducing the cushion-
ing ability of the tires. In addition, driving
on rough roads may cause damage to
the tires themselves, as well as the vehi-
cle’s wheels and body.
Tire rotation

2686-3. Do-it-yourself maintenance
information will not be updated.
If this accidentally occurs, either turn the
engine switch to off and then to IGNITION
ON mode, or initialize the system after
checking that the tire pressure is properly
adjusted.
Your vehicle is equipped with a tire
pressure warning system that uses tire
pressure warning valves and transmit-
ters to detect low tire inflation pressure
before serious problems arise.
 The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. ( P.71)
The illustration used is intended as an
example, and may differ from the image
that is actually displayed on the multi-infor-
mation display.
 If the tire pressure drops below a
predetermined level, the driver is
warned by a screen display and a
warning light. ( P.300)
■Routine tire inflation pressure checks
The tire pressure warning system does not
replace routine tire inflation pressure
checks. Make sure to check tire inflation
pressure as part of your routine of daily
vehicle checks.
■Tire inflation pressure
●It may take a few minutes to display the
tire inflation pressu re after the engine
switch is turned to IGNITION ON mode.
It may also take a few minutes to display
the tire inflation pressure after inflation
pressure has b een adjusted.
●Tire inflation pressure changes with tem-
perature. The displaye d values may also
be different from the values measured
using a tire pressure gauge.
■Situations in which the tire pressure
warning system may not operate prop-
erly
●In the following cases, the tire pressure
warning system may not operate prop-
erly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is
not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is
not of the specified size.
• Tire chains, etc. are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehi-
cle, particularly around the wheels or
wheel housings.
• If the tire inflation pressure is extremely
higher than the specified level.
• If tires not equipped with tire pressure
Tire pressure warning system

2696-3. Do-it-yourself maintenance
6
Maintenance and care
warning valves and transmitters are used.
• If the ID code on the tire pressure warn- ing valves and transmitters is not regis-
tered in the tire pressure warning
computer.
●Performance may be affected in the fol-
lowing situations.
• Near a TV tower, electric power plant,
gas station, radio stat ion, large display,
airport or other faci lity that generates
strong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phone or other wireless
communication device
If tire position information is not correctly
displayed due to the radio wave conditions,
the display may be corrected by driving and
changing the radio wave conditions.
●When the vehicle is parked, the time
taken for the warning to start or go off
could be extended.
●When tire inflation pressure declines rap-
idly for example when a tire has burst, the
warning may not function.
When replacing the tires or wheels, the
tire pressure warning valve and trans-
mitters must be installed to the wheels
which will be installed to the vehicle.
When new tire pressure warning
valves and transmitte rs are installed,
new ID codes must be registered in the
tire pressure warning computer and
the tire pressure warning system must
be initialized. ( P.271)
■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 rotating the tires.
 When the tire inflation pressure is
changed such as when changing
traveling speed or load weight.
 When changing the tire size.
Installing tire pressure warning
valves and transmitters
NOTICE
■Repairing or replac ing 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 pressure 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. After use of liquid seal-
ant, make sure to re place the tire pres-
sure warning valve and transmitter when
repairing or replacing the tire. ( P.269)
Initializing the tire pressure
warning system

2706-3. Do-it-yourself maintenance
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, turn
the engine switch off and wait 20
minutes or more.
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 th e 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 Start the engine. ( P.127)
4 Press and hold the tire pressure
warning reset switch until the tire
pressure warning light blinks slowly
3 times.
Then a message will be displayed on the
multi-information display.
5Drive straight (with occasional left
and right turns) at approximately
25 mph (40 km/h) or more for
approximately 10 to 30 minutes.
Initialization is complete when the position
of each tire is determined and the inflation pressure of each tire
is displayed on the
multi-information display.
■Initialization procedure
●Make sure to carry out initialization after
adjusting the tire inflation pressure.
Also, make sure the tires are cold before
carrying out initialization or tire inflation
pressure adjustment.
●If you have accidentally turned the engine
switch off during initialization, it is not
necessary to press the reset switch again
as initialization will restart automatically
when the engine switch has been turned
to IGNITION ON mode for the next
time.
●If you accidentally press the reset switch
when initialization is not necessary, adjust
the tire inflation pressure to the specified
level when the tires are cold, and conduct
initialization again.
■If the tire pressure warning system is not
initialized properly
●In the following situations, initialization
may take longer than usual to be com-
pleted or may not be possible. (Usually,
the vehicle will need to be driven for
approximately 10 to 30 minutes to com-
plete initialization.) If initialization is not
complete after drivin g approximately 30
minutes, continue driving for a while.
• If the vehicle is driven on an unpaved road, it may take longer to complete ini-
tialization.
• If the vehicle is backed up while perform-
ing initialization, data collected during ini-
tialization will be cleared and it will take
longer than normal to complete.
• If the vehicle is driven in heavy traffic or another situation where other vehicles
are driven close by, it may take time for
the system to recognize the tire pressure
warning valve and transmitters of your
vehicle over those of other vehicles.
If initialization is not complete after driving
for approximately 1 hour, park the vehicle in
a safe place for approximately 20 minutes
and then drive the vehicle again.
●In the following situations, initialization
will not be started or was not completed
properly and the system will not operate