inflation pressure LEXUS RC300H 2017 User Guide

4897-3. Do-it-yourself maintenance
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Maintenance and care
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■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 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 extr emely higher than the specified level. • If tires not equipped with tire pressure warning valves and transmitters 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 phone or other wireless communication deviceIf 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 rapi dly for example when a tire has burst, the warning may not function.
■The initialization operation
●Make sure to carry out initialization af ter adjusting the tire inflation pressure. Also, make sure the tires are cold before carry ing out initialization or tire inflation pres-
sure adjustment.
●If you have accidentally turned the power switch off during initialization, it is not neces- sary to press the reset switch again as init ialization will restart automatically when the
power switch has been turned to 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 leve l when the tires are cold, and conduct initial-
ization again.
■Warning performance of the tire pressure warning system
The warning of the tire pressure warning syst em will change in accordance with the con-
ditions under which it was initialized. For this reason, the system may give a warning even if the tire pressure does not reach a low enough level, or if the pressure is higher than the pressure that was adjusted to when the system was initialized.

4907-3. Do-it-yourself maintenance
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■When initialization of the tire pressure warning system has failed
Initialization can be co mpleted in a few minutes. However, in the following cases, the set- tings have not been recorded and the syst em will not operate properly. If repeated
attempts to record tire inflation pressure settings are unsuccessful, have the vehicle inspected by any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
●When operating the tire pressure warning re set switch, the tire pressure warning light does not blink 3 times.
●After carrying out the initializat ion procedure, the tire pressure warning light blinks for 1
minute then stays on after driving for 20 minutes.
■Registering ID codes
The ID codes of the tire pressure warning valve and transmitters for two sets of wheels
can be registered.
It is not necessary to register the ID codes wh en replacing normal tires with snow tires, if the ID codes for the wheels of both normal tires and snow tires are registered before-
hand.
For information about changing ID codes, as k any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.

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Maintenance and care
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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 acc ident 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 th an 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 been used on another vehicle. Do not use tires if you do not know how they were used previously.
●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 re set switch without first adjusting the tire
inflation pressure to the specified level. Ot herwise, 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 other than implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemakers or implantable cardioverter defibrillators should consult the manufacturer of the device for information about itsoperation under the influence of radio waves.
Radio waves could have unexpected effects on the operation of such medical devices.
●People with implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemak- ers or implantable cardioverter defibrillatorsshould not come within 450 mm (17.7 in.) of
the tire pressure warning system initiators. The radio waves may affect the operation ofsuch devices.

4987-3. Do-it-yourself maintenance
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NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters and tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact any authorized Lexus de aler or repairer, or another duly quali- fied and equipped professional as the tire pressure warning 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 valv es 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 sealants, the tire pressure warning valve and trans- mitter may not operate properly. If a liquid sealant is used, contact any authorizedLexus dealer or repairer, or another duly qu alified and equipped professional or other
qualified service shop as soon as possible. After use of liquid sealant, make sure to replace the tire pressure warning valve and transmitter when repairing or replacing the tire. ( P. 486)
■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 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. Therefore, pay attention 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.

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Maintenance and care
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■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, have it checked by any authorized Lexus dealer or repairer, or another duly qua lified and equipped professional.
■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
1.5 km or 1 mile, 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 prop erly inflated based only on its appearance.
●It is normal for the tire inflation pressure to be higher after driving as heat is generated in the tire. Do not reduce tire inflation pressure after driving.
●Passengers and luggage weight should be placed so that the vehicle is balanced.
Tire inflation pressure
Make sure to maintain proper tire infl ation pressure. Tire inflation pressure
should be checked at least once per month. However, Lexus recommends
that tire inflation pressure be checked once every two weeks. ( P. 604)

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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 damage
●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 moisture may get into the valve and cause an airleak, resulting in decrease d tire inflation pressure.

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Maintenance and care
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When replacing wheels, care should be taken to ensure that they are equivalent
to those removed in load capacity, diameter, rim width and inset*.
Replacement wheels are available at any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
*: 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 straightened
●Use only Lexus wheel nuts and wrenches designed for use with your alumi-
num wheels.
●When rotating, repairing or changing your tires, check that the wheel nuts are
still tight after driving 1600 km (1000 miles).
●Be careful not to damage the aluminum wheels when using tire chains.
●Use only Lexus genuine balance weights or equivalent and a plastic or rubber
hammer when balancing your wheels.
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and transmit- ters that allow the tire pressure warning sy stem to provide advance warning in the event
of a loss in tire inflation pressure. Whenever wheels are replaced, tire pressure warning valves and transmitters must be installed. (P. 486)
Wheels
If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the wheel or cause a loss of handling control.
Wheel selection
Aluminum wheel precautions

5398-2. Steps to take in an emergency
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When trouble arises
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Automatic headlight leveling system warning light Indicates a malfunction in the au tomatic headlight leveling system
 Have the vehicle inspected by any authorized Lexus dealer or repairer, or another duly qualified and equipped professionalimmediately.
Open door warning light (warning buzzer)*1
Indicates that a door or the trunk is not fully closed
 Check that both side doors and the trunk are closed.
Low fuel level warning light Indicates that remaining fuel is approximately 10 L (2.6 gal., 2.2 Imp.gal.) or less
 Refuel the vehicle.
Driver’s and front passenger’s seat belt reminder light (warning
buzzer)*2
Warns the driver and/or front passe nger 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.
Rear passengers’ seat belt reminder lights (warning buzzer)*2
Warns the rear passengers to fasten their seat belts  Fasten the seat belt.
Master warning light A buzzer sounds and the warning light comes on and flashes to
indicate that the master warnin g system has detected a malfunc- tion. P. 542
Tire pressure warning light
When the light comes on: Low tire inflation pressure such as• Natural causes ( P. 540)
• Flat tire ( P. 563)  Adjust the tire inflation pressure to the specified level. The light will turn off after a few minutes. If the warning light
does not turn off after a few minutes, perform initialization ( P. 487). If the light does not turn off after performing initialization,have the system checked by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
When the light comes on af ter blinking for 1 minute:
Malfunction in the tire pressure warning system  Have the system checked by any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
Warning lightWarning light/Details/Actions

5408-2. Steps to take in an emergency
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*1: Open door warning buzzer:
 P. 544
*2: Seat belt warning buzzer:
The seat belt warning buzzer sounds to al ert the driver, front passenger and rear pas- sengers that his or her seat belt is not fastened. The buzzer sounds for 30 seconds
after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat belt is still unfastened, the buzzer will sound in a different tone for 90 more seconds.
■Front passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on a front passenger seat, the front passenger detection sensormay cause the warning light to flash and the warning buzzer to sound even if a passen-
ger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the warn- ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes completely empty. If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized Lexus dealer or repairer, or another duly qualified and eq uipped professional 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
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even afte r several minutes, check that the tire infla- tion pressure is at the specifie d level and carry out initialization.
The warning light may come on again if the above operations are conducted without first allowing the tire temperature to lower sufficiently.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air leaks and tire inflation pressure changes caused by temperature. In this case, adjustingthe tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with the spare tire (if equipped)
The spare tire is not equipped with a tire pre ssure warning valve and transmitter. If a tire
goes flat, the tire pressure warning light will no t turn off even though the flat tire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 489

5418-2. Steps to take in an emergency
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When trouble arises
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■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the power switch is turned to ON mode, have it checked by any authorized Lexus dealer or
repairer, or another duly qua lified and equipped professional.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact any authorized Lexus dealer or repairer, or another duly qualified and equipped professional. The vehicle will
become extremely unstable during braking, and the ABS system may fail, which could cause an accident resulting in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy. If the steering wheel becomes heavier than us ual when operating, hold firmly and oper- ate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause a loss of vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressureimmediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat tire. Check the tires. If a tire is flat, repair the flat tire by using emergency tire puncture repair kit.
●Avoid abrupt maneuvering and braking. If th e vehicle tires deteriorate, you could lose
control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pressure warning system may not operate properly.