inflation pressure LEXUS RCF 2018 User Guide

4136-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 6
Maintenance and care Your vehicle is equipped with a tire pressure warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure before
serious problems arise. ●
If the tire pressure drops below a predet ermined level, the driver is warned by
a screen display and a warning light. (  P. 455, 477)●
The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. (  P. 103, 118)The illustration used is intended as an
example, and may differ from the image
that is actually disp layed on the multi-
information display.
◆ Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pr essure warning valv es and transmitters
must also be installed.
When new tire pressure wa rning valves and transmitters are installed, new ID
codes must be registered in the tire pressure warning computer and the tire
pressure warning system must be initia lized. Have tire pressure warning valve
and transmitter ID codes registered by your Lexus dealer. (  P. 414)
◆ Initializing the tire pressure warning system ■
The tire pressure warning system must be initialized in the following circum-
stances: ●
When rotating the tires. ●
When the tire inflation pressure is changed such as when changing travel-
ing speed. ●
When changing the tire size.
When the tire pressure warning system is initialized, the current tire inflation
pressure is set as the benchmark pressure.Tire pressure warning system

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How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off.Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to th e specified cold tire inflation pressure
level. (  P. 548)Make sure to adjust the tire pressure to the specified cold tire inflation pressure
level. The tire pressure warning system will operate based on this pressure level.
Turn the engine switch to IGNITION ON mode.
Press and hold the tire pressure
warning reset switch until the tire
pressure warning light blinks
slowly 3 times.
Wait for a few minutes with the engine switch in IGNITION ON mode and
then turn the engine switch off.
◆ Registering ID codes
The tire pressure warning valve and tran smitter is equipped with a unique ID
code. When replacing a tire pressure warning valve and transmitter, it is nec-
essary to register the ID code. Have the ID code registered by your Lexus
dealer. 1
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4156-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 6
Maintenance and care ■
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 enou gh to expose the fabric, and
bulges indicating internal damage ●
A tire goes flat repeatedly or cannot be properly repaired due to the size or location of
a cut or other damage
If you are not sure, consult your Lexus dealer. ■
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 proper ly. After driving for about 20 minutes, the
tire pressure warning light blinks for 1 minu te and stays on to indicate a system malfunc-
tion. ■
Tire life
Any tire over 6 years old must be checked by a qualified technician even if it has seldom
or never been used or damage is not obvious.■
Routine tire inflation pressure checks
The tire pressure warning syst em does not replace routine tire inflation pressure checks.
Make sure to check tire inflat ion pressure as part of your routine of daily vehicle checks.■
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 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 th at the tire pressure is properly adjusted.■
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 comp ared to standard tires. 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.

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RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
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, whichever is
greater.
■
Tire types ●
Summer tires
Summer tires are high-speed performance ti res best suited to highway driving under
dry conditions. Since summer tires do not have the same traction performance as
snow tires, summer tires are inadequate for driving on snow-covered or icy roads. For
driving on snow-covered roads or icy road s, the use of snow tires is recommended.
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, how-
ever, do not have adequate traction perfor mance compared with snow tires in heavy
or loose snow. Also, all season tires fall short in acceleration and handling perfor-
mance 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 ti res of the same size, construction and load capacity as the
originally installed tires. Since your vehicle has radial tires as or iginal equipment, make
sure your snow tires also have radial cons truction. Do not install studded tires without
first checking local regulations for possible restrictions. Snow tires should be installed
on all wheels. (  P. 320)■
If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tire s as snow tires is lost.For the GAWR, see the Ce rtification Label. For
the maximum load of the tire, see the load limit
at maximum cold tire inflation pressure men-
tioned on the sidewall of the tire. (  P. 557)

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Maintenance and care ■
Situations in which the tire pressure warning system may not operate properly ●
In the following cases, the tire pressure warning system may not operate properly.
• 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 th e 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 extr emely higher than the specified level.
• If tires not equipped with tire pressure warning valves and tr ansmitters are used.
• If the ID code on the tire pressure warning valves and transmitters is not registered
in the tire pressure warning computer. ●
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility that generates st rong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phon e 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 rapidly for example when a tire has burst, the
warning may not function. ■
The initialization operation ●
Make sure to carry out initialization afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment. ●
If you have accidentally turned the engine swit ch off during initialization, it is not neces-
sary to press the reset switch again as initialization will re start automatically when the
engine switch has been turned to IG NITION ON mode for the next time.●
If you accidentally press the re set switch when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are co ld, and conduct initial-
ization again. ■
When initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following cases, the set-
tings have not been recorded and the system will not operate properly. If repeated
attempts to record tire inflation pressure settings are unsuccessful, have the vehicle
inspected by your Lexus dealer. ●
When operating the tire pres sure warning reset switch, th e tire pressure warning light
does not blink 3 times. ●
After carrying out the initializat ion procedure, the tire pressu re warning light blinks for 1
minute then stays on after driving for 20 minutes.

418 6-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)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 dangerous han-
dling characteristics, which may lead to an accident resu lting 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-belted or bias-ply tires). ●
Do not mix summer, all season and snow tires. ●
Do not use tires that have be en used on another vehicle.
Do not use tires if you do not know how they were used previously. ●
Vehicles with a compact spare tire: Do no t tow if your vehicle has a compact spare
tire installed. ●
Vehicles with an emergency tire puncture repair kit: Do not tow anything if a tire that
has been repaired using the emergency tire puncture repair kit is installed. The load
on the tire may cause unexpected damage to the tire. ■
When initializing the tire pressure warning system
Do not operate the tire pressure warning reset switch without first adjusting the tire
inflation pressure to the spec ified level. Otherwis e, the tire pressure warning light may
not come on even if the tire inflation pressu re is low, or it may come on when the tire
inflation pressure is actually normal. ■
Caution regarding interference with electronic devices
●
Users of any electrical medical device ot her than implantable cardiac pacemakers,
cardiac resynchronization th erapy-pacemakers or implantable cardioverter defibril-
lators should consult the manufacturer of the device for information about its opera-
tion under the influence of radio waves.
Radio waves could have unexpected effects on the operation of such medical
devices. ●
People with implantabl e cardiac pacemakers,
cardiac resynchronization therapy-pacemak-
ers or implantable cardioverter defibrillators
should not come within 17.7 in. (450 mm) of
the tire pressure warn ing system initiators.
The radio waves may affect the operation of
such devices.

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Maintenance and care NOTICE ■
Repairing or replacing tires, wheels, tire pressure warning valv es, transmitters 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 warning valves and trans-
mitters may be damaged if not handled correctly. ●
Make sure to install the tire valve caps. If the tire valve caps ar e 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 pressu re warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter may not operate properly. If a liquid sealant is used, contact your Lexus dealer or
other qualified service shop as soon as possi ble. After use of liquid sealant, make sure
to replace the tire pressure warning valve and transmitter when repairing or replacing
the tire. (  P. 413)■
Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause lo sses in tire inflation pre ssure, reducing the cushioning
ability of the tires. In addition, driving on rough roads may cause damage to the tires
themselves, as well as the vehicle’s wheels and body. ■
Low profile tires
Low profile tires may cause greater damage than usual to the tire wheel when sustain-
ing impact from the road surface. Ther efore, pay attentio n to the following:●
Be sure to use proper tire inflation pressu re. If tires are under-inflated, they may be
damaged more severely. ●
Avoid potholes, uneven pavement, curbs an d other road hazards. Failure to do so
may lead to severe tire and wheel damage. ■
If tire inflation pressure of ea ch tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

420 6-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
(  P. 548)
Tire inflation pressure Tire inflation pressure

4216-3. Do-it-yourself maintenance
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Maintenance and care Tire valve
Tire pressure gauge
Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the gauge gradations.
If the tire inflation pressure is not at the recommended level, adjust the pres-
sure.
If you add too much air, press the center of the valve to deflate.
After completing the tire inflation pressure measuremen t and adjustment,
apply soapy water to the valve and check for leakage.
Put the tire valve cap back on. ■
Tire inflation pressure check interval
You should check tire inflation pressure ev ery two weeks, or at least once a month.
Do not forget to check the spare. ■
Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:●
Reduced fuel economy ●
Reduced driving comfort and poor handling ●
Reduced tire life due to wear ●
Reduced safety ●
Damage to the drivetrain
If a tire needs frequent inflating, ha ve it checked by your Lexus dealer.Inspection and adjustment procedure 1
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422 6-3. Do-it-yourself maintenance
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Instructions for checking tire inflation pressure
When checking tire in flation pressure, ob serve 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 inflation pressure reading. ●
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 tire inflat ion pressure to be higher after driving as heat is generated
in the tire. Do not reduce tire inflation 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 resultin g in death or serious injury:●
Excessive wear ●
Uneven wear ●
Poor handling ●
Possibility of blowouts resu lting from overheated tires●
Air leaking from between tire and wheel ●
Wheel deformation and/or tire damage ●
Greater possibility of tire damage while driving (due to road hazards, expansion
joints, sharp edges in the road, etc.)
NOTICE ■
When inspecting and adjust ing tire inflation pressure
Be sure to put the tire valve caps back on.
If a valve cap is not installed, dirt or moisture may get into the valve and cause an air
leak, resulting in decreased tire inflation pressure.