
4657-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53C61E)
■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 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.
It is difficult to judge if a tire is properly 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 inflation 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. 568)
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4667-3. Do-it-yourself maintenance
IS300h_EE(OM53C61E)
CAUTION
■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 the valve caps are not installed, dirt or moisture may get into the valve and cause air
leakage, which could result in a flat tire.
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4677-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53C61E)
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 system 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. 4 5 1 )
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
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4687-3. Do-it-yourself maintenance
IS300h_EE(OM53C61E)
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the Owner’s
Manual, as this may result in a loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire. Doing
so may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves and
transmitters, make sure to have tires serviced by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional or other qualified ser-
vice shop. In addition, make sure to purchase your tire pressure warning valves and
transmitters at any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
●Ensure that only genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-genu-
ine wheels.
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5058-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53C61E)
Automatic headlight leveling system warning light
Indicates a malfunction in the automatic headlight leveling system
→Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
Open door warning light (warning buzzer)*2
Indicates that a door or the trunk is not fully closed
→Check that all the 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)
*3
Warns the driver and/or front passenger 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)*3
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 warning system has detected a malfunc-
tion.
→P. 5 0 9
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes (→P. 5 0 6 )
• Flat tire (→P. 5 2 6 , 5 4 0 )
→Adjust the tire inflation pressure to the specified level.
The light will turn off after a few minutes. In case the light does
not turn off even if the tire inflation pressure is adjusted, have the
system checked by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
When the light comes on after 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
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5068-2. Steps to take in an emergency
IS300h_EE(OM53C61E)*
1: Parking brake engaged warning buzzer:
→P. 5 1 3
*2: Open door warning buzzer:
→P. 5 1 1
*3: Seat belt warning buzzer:
The seat belt warning buzzer sounds to alert 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.
■Passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on a passenger seat, the passenger detection sensor may cause the
warning light to flash and the warning buzzer to sound even if a passenger 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 equipped professional as soon as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient of 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 after several minutes, check that the tire infla-
tion pressure is at the specified 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, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■Conditions that the tire pressure warning system may not function properly
→P. 4 5 4
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5078-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53C61E)
■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 qualified and equipped professional.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
CAUTION
■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 usual 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.
XVehicles with an emergency tire puncture repair kit
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressure
immediately.
●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 the vehicle tires deteriorate, you could lose
control of the steering wheel or the brakes.
XVehicles with run-flat tires
●Decelerate to the lowest appropriate speed as soon as possible. Do not drive over 60
km/h (37 mph).
●Check and adjust the tire inflation pressure immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat tire. Have the tire replaced by the nearest
authorized Lexus dealer or repairer, or another duly qualified and equipped profes-
sional.
●Avoid abrupt maneuvering and braking. If the 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.
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5088-2. Steps to take in an emergency
IS300h_EE(OM53C61E)
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.
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