Page 481 of 628
4677-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
CAUTION
Proper inflation is critical to save tire performance
Keep your tires properly inflated. Otherwise, the following conditions may
occur and result in an accident causing death or serious injury:
Excessive wear
Uneven wear
Poor handling
Possibility of blowouts resulting from overheated tires
Poor sealing of the tire bead
Wheel deformation and/or tire separation
A greater possibility of tire damage from road hazards
NOTICE
When inspecting and adjusting tire inflation pressure
Be sure to put the tire valve caps back on.
Without the valve caps, dirt or moisture could get into the valve and cause air
leakage, which could result in an accident. If the caps are lost, replace them as
soon as possible.
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4687-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
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 “off-
set”.
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
aluminum 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
transmitters that allow the tire pressure warning system to provide advance warn-
ing in the event of a loss in tire inflation pressure. Whenever wheels are replaced,
tire pressure warning valves and transmitters must be installed. (P. 451)
Wheels
If a wheel is bent, cracked or heavily corroded, it should be replaced.
Otherwise, the tire may separate from the wheel or cause a loss of han-
dling control.
Wheel selection
Aluminum wheel precautions
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4697-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
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 service shop. In addition, make sure to purchase your tire pres-
sure 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-genuine wheels.
Page 511 of 628

497
8When trouble arises
IS300h_EE(OM53B95E)
8-1. Essential information
Emergency flashers ........... 498
If your vehicle has to be
stopped in an
emergency ....................... 4998-2. Steps to take in an
emergency
If your vehicle needs to
be towed.......................... 500
If you think something
is wrong .......................... 506
If a warning light turns
on or a warning buzzer
sounds ............................. 507
If a warning message is
displayed ......................... 513
If you have a flat tire
(vehicles without
run-flat tires) ................... 530
If you have a flat tire
(vehicles with
run-flat tires) ................... 544
If the hybrid system will
not start ........................... 545
If the shift lever cannot
be shifted from P ............ 547
If the electronic key
does not operate
properly........................... 548
If the 12-volt battery is
discharged ....................... 550
If your vehicle overheats .. 555
If the vehicle becomes
stuck................................ 559
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5068-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
Flat-looking tires or uneven tire wear
Engine coolant temperature gauge needle continually points higher
than normal.
Changes in exhaust sound
Excessive tire squeal when cornering
Strange noises related to the suspension system
Pinging or other noises related to the hybrid system
Engine missing, stumbling or running roughly
Appreciable loss of power
Vehicle pulls heavily to one side when braking
Vehicle pulls heavily to one side when driving on a level road
Loss of brake effectiveness, spongy feeling, pedal almost touches the
floor
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 526 of 628

5128-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
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 operate 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.
Vehicles 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
adjustment, 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.
Vehicles 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
adjustment, 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 professional.
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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5138-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
NOTICE
Precaution when installing a different tire
When differently constructed tires or tires of different makers, models or tread
patterns are installed, the tire pressure warning system may not operate prop-
erly.
Page 545 of 628
5318-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
Stop the vehicle in a safe place on a hard, flat surface.
Set the parking brake.
Shift the shift lever to P.
Stop the hybrid system.
Turn on the emergency flashers. (P. 4 9 8 )
If you have a flat tire (vehicles without run-flat tires)
Your vehicle is equipped with an emergency tire puncture repair kit.
A puncture caused by a nail or screw passing through the tire tread can be
repaired temporarily with the emergency tire puncture repair kit.
CAUTION
If you have a flat tire
Do not continue driving with a flat tire.
Driving even a short distance with a flat tire can damage the tire and the wheel
beyond repair, which could result in an accident.
Before repairing the vehicle
Location of the emergency tire puncture repair kit