
7566-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
Your vehicle is equipped with a tire pressure warning system that
uses tire pressure warning valves and transmitters to detect low tire
inflation pressure before serious problems arise.
Vehicles without the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. (P. 834)
Vehicles with the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver
is warned by a screen display and a warning light. (P. 859)
The tire pressure detected by the tire pressure warning system
can be displayed on the multi-information display. (P. 117)
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and
transmitters must also be installed.
When new tire pressure warning 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
initialized. Have tire pressure warning valve and transmitter ID
codes registered by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional. (P. 758)
Tire pressure warning system (if equipped)

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Maintenance and care
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Initializing the tire pressure warning system
The tire pressure warning system must be initialized in the fol-
lowing circumstances:
When rotating the tires.
When the tire inflation pressure is changed such as when
changing traveling speed.
When the tire pressure warning system is initialized, the current
tire inflation pressure is set as the benchmark pressure.
How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the power switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire infla-
tion pressure level. (P. 936)
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 power switch to ON mode.
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Maintenance and care
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When to replace your vehicle’s tires
Tires should be replaced if:
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
location of a cut or other damage
If you are not sure, consult with any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Replacing tires and wheels (vehicles with the tire pressure warning system)
If the ID code of the tire pressure warning valve and transmitter is not regis-
tered, the tire pressure warning system will not work properly. After driving
for about 10 minutes, the tire pressure warning light blinks for 1 minute and
stays on to indicate a system malfunction.
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 system does not replace routine tire inflation pres-
sure checks. Make sure to check tire inflation pressure as part of your routine
of daily vehicle checks.
When rotating the tires (vehicles with the tire pressure warning system featur-
ing a tire inflation pressure display function)
Make sure that the power switch is off. If the tires are rotated while the power
switch is in ON mode, the tire position information will not be updated.
If this accidentally occurs, either turn the power switch to off and then to ON
mode, or initialize the system after checking that the tire pressure is properly
adjusted.

7606-3. Do-it-yourself maintenance
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Low profile tires (except 225/50R17 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 tires.
Be sure to use snow tires or tire chains on snowy and/or icy roads and drive
carefully at a speed appropriate for road and weather conditions. (P. 436)
If the tread on snow tires wears down below 4 mm (0.16 in.)
The effectiveness of the tires as snow tires is lost.
Situations in which the tire pressure warning system may not operate properly
(vehicles with the tire pressure warning system)
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 Equip-
ment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• Lock nuts 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 vehicle, particularly around the
wheels or wheel housings.
• If the tire inflation pressure is extremely higher than the specified level.
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large
display, airport or other facility that generates strong radio waves or elec-
trical noise
• When carrying a portable radio, cellular phone, cordless phone or other
wireless communication device
Vehicles with the tire inflation pressure display function: 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 condi-
tions.
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.

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Maintenance and care
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The initialization operation (vehicles with the tire pressure warning system)
Make sure to carry out initialization after adjusting the tire inflation pres-
sure.
Also, make sure the tires are cold before carrying out initialization or tire
inflation pressure adjustment.
If you have accidentally turned the power switch off during initialization, it
is not necessary to press the reset switch again as initialization 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 neces-
sary, adjust the tire inflation pressure to the specified level when the tires
are cold, and conduct initialization again.
Warning performance of the tire pressure warning system (if equipped)
The warning of the tire pressure warning system will change in accordance
with the conditions 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.
When initialization of the tire pressure warning system has failed (vehicles
with the tire pressure warning system)
Initialization can be completed in a few minutes. However, in the following
cases, the settings 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 any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
When operating the tire pressure warning reset switch, the tire pressure
warning light does not blink 3 times.
After carrying out the initialization procedure, the tire pressure warning
light blinks for 1 minute then stays on after driving for 20 minutes.
Registering ID codes (vehicles with the tire pressure warning system)
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 when replacing normal tires with
snow tires, if the ID codes for the wheels of both normal tires and snow tires
are registered beforehand.
For information about changing ID codes, ask any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.

7686-3. Do-it-yourself maintenance
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CAUTION
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dan-
gerous 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-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.
Vehicles with a compact spare tire: Do not tow if your vehicle has a com-
pact spare tire installed.
Vehicles with an emergency tire puncture repair kit (if equipped): 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 (vehicles with the tire
pressure warning system)
Do not operate the tire pressure warning reset switch without first adjusting
the tire inflation pressure to the specified level. Otherwise, the tire pressure
warning light may not come on even if the tire inflation pressure is low, or
it may come on when the tire inflation pressure is actually normal.

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CAUTION
Caution regarding interference with electronic devices (vehicles with the
tire pressure warning system featuring a tire inflation pressure display func-
tion)
Users of any electrical medical device other than implantable cardiac
pacemakers, cardiac resynchronization therapy-pacemakers or implant-
able cardioverter defibrillators should consult the manufacturer of the
device for information about its operation under the influence of radio
waves.
Radio waves could have unexpected effects on the operation of such med-
ical devices.
People with implantable cardiac pace-
makers, cardiac resynchronization ther-
apy-pacemakers or implantable
cardioverter defibrillators should not
come within 450 mm (17.7 in.) of the
tire pressure warning system initiators.
The radio waves may affect the opera-
tion of such devices

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Maintenance and care
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NOTICE
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 (except 225/50R17 tires)
Low profile tires may cause greater damage 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.