4517-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
Your vehicle is equipped with a tire pressure warning system that uses tire
pressure warning valves and transmitters to detect low tire inflation pres-
sure before serious problems arise.
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. (P. 509)
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters 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. 452)
Initializing the tire pressure warning system
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.
When the tire pressure warning system is initialized, the current tire
inflation pressure is set as the benchmark pressure.
Tire pressure warning system
4537-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
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 fab-
ric, 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 any authorized Lexus dealer or repairer, or another
duly qualified and equipped professional.
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
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 pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
Low profile tires (except 16-inch 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.
*: Tire chains cannot be mounted on the 18-inch tires. Snow tires should be used
instead.
If the tread on snow tires wears down below 4 mm (0.16 in.)
The effectiveness of the tires as snow tires is lost.
4547-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Situations in which the tire pressure warning system may not operate properly
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.
• 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.
• 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 reg-
istered 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 dis-
play, airport or other facility that generates strong radio waves or electrical
noise
• When carrying a portable radio, cellular phone, cordless phone or other
wireless communication device
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 after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carrying out initialization or tire infla-
tion 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 auto-
matically 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 level when the tires are cold,
and conduct initialization again.
Warning performance of the tire pressure warning system
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.
4587-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
CAUTION
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-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 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 specified level. Otherwise, the tire pressure warn-
ing 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.
4597-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
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 dealer or repairer, or another
duly qualified 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 valves and the tire pressure warn-
ing 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
transmitter may not operate properly. If a liquid sealant is used, contact any
authorized Lexus dealer or repairer, or another duly qualified and equipped
professional or other qualified service shop as soon as possible. Make sure to
replace the tire pressure warning valve and transmitter when replacing the tire.
(P. 451)
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 cush-
ioning ability of the tires. In addition, driving on rough roads may cause dam-
age to the tires themselves, as well as the vehicle’s wheels and body.
Low profile tires (except 16-inch 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 follow-
ing:
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.
4617-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
Remove the 12-volt battery cover. (P. 447)
Take out the jack.
For tightening
For loosening
CAUTION
Using the tire jack
Observe the following precautions.
Improper use of the tire jack may cause the vehicle to suddenly fall off the jack,
leading to death or serious injury.
Do not use the tire jack for any purpose other than replacing tires or installing
and removing tire chains.
Only use the tire jack that comes with this vehicle for replacing a tire.
Do not use it on other vehicles, and do not use other tire jacks for replacing
tires on this vehicle.
Put the jack properly in its jack point.
Do not put any part of your body under the vehicle while it is supported by the
jack.
Do not start the hybrid system or drive the vehicle while the vehicle is sup-
ported by the jack.
Do not raise the vehicle while someone is inside.
When raising the vehicle, do not put an object on or under the jack.
Do not raise the vehicle to a height greater than that required to replace the
tire.
Use a jack stand if it is necessary to get under the vehicle.
When lowering the vehicle, make sure that there is no-one near the vehicle. If
there are people nearby, warn them vocally before lowering.
Taking out the jack
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2
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4627-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Chock the tires.
Slightly loosen the wheel nuts
(one turn).
Turn the tire jack portion “A” by
hand until the notch of the jack is
in contact with the jack point.
The jack point guides are located
under the rocker panel. They indi-
cate the jack point positions.
Replacing a tire
1
TireWheel chock positions
FrontLeft-hand sideBehind the rear right-hand side tire
Right-hand sideBehind the rear left-hand side tire
RearLeft-hand sideIn front of the front right-hand side tire
Right-hand sideIn front of the front left-hand side tire
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3
4667-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:
Reduced fuel efficiency
Reduced driving comfort and tire life
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 qualified 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.
The appearance of the tire can be misleading. In addition, tire inflation pressure
that is even just a few pounds off can affect ride quality and handling.
Do not reduce tire inflation pressure after driving. It is normal for tire inflation
pressure to be higher after driving.
Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
Tire inflation pressure
Make sure to maintain proper tire inflation pressure. Tire inflation pres-
sure should be checked at least once per month. However, Lexus recom-
mends that tire inflation pressure be checked once every two weeks.
(P. 570)