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5437-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
■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 retailer or
Lexus authorized repairer, or any reliable repairer.
■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 ge t 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 inflation pressure. Tire inflation pressure
should be checked at least once pe r month. However, Lexus recommends
that tire inflation pressure be checked once every two weeks. (P. 652)
Page 544 of 692
5447-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
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 resultin g 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 adjust ing 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 air leak, resulting in decrease d tire inflation pressure.
Page 545 of 692

5457-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
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 retailer or Lexus
authorized repairer, or any reliable repairer.
*: 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. 526)
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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5467-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
WARNING
■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 se rviced by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer or other qualified service shop. In addition, make sure to purchase your tire pressure warning valves and transmitters at
any authorized Lexus retailer or Lexus author ized repairer, or any reliable repairer.
●Ensure that only genuine Lexus wheels are used on your vehicle. Tire pressure warning valves and transmitte rs may not work properly with non-genu-
ine wheels.
Page 565 of 692

565
8When trouble arises
IS300h_EE(OM53D89E)
8-1. Essential information
Emergency flashe rs ..................566
If your vehicle has to
be stopped in an
emergency................................. 567
8-2. Steps to take in an
emergency
If your vehicle needs to
be towed .....................................568
If you think something is
wrong ........................................... 574
If a warning light turns
on or a warning buzzer
sounds.......................................... 575
If a warning message is
displayed ..................................... 581
If you have a flat tire
(vehicles with
emergency tire puncture
repair kit) ..................................... 610
If you have a flat tire
(vehicles with run-flat
tires).............................................. 625
If the hybrid sy stem will not
start ............................................... 626
If the electronic key does
not operate properly ............. 628
If the 12-volt battery is
discharged .................................. 631
If your vehicle overheats ......... 636
If the vehicle becomes
stuck ...............................................641
Page 572 of 692

5728-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
■While towing
If the hybrid system is off, the power assist for the brakes and steering will not function,
making steering and braking more difficult.
■Wheel nut wrench
Wheel nut wrench is installed in the trunk. ( P. 537)
WARNING
Observe the following precautions. Failure to do so may result in death or serious injury.
■When towing the vehicle
■While towing
●When towing using cables or chains, avoid sudden starts, etc. which place excessive
stress on the towing eyelets, cables or chains. The towing eyelets, cables or chains may become damaged, broken debris ma y hit people, and cause serious damage.
●Do not turn the power switch off.
There is a possibility that the steering wheel is locked and cannot be operated.
■Installing towing eyelet to the vehicle
Make sure that towing eyel et is installed securely.
If not securely installed, towing ey elet may come loose during towing.
Be sure to transport the vehicle with all four
wheels raised off the ground. If the vehicle is
towed with the tires contacting the ground, the
drivetrain and related parts may be damaged, an accident may occur due to a change in
direction of the vehicle or electricity generated
by the operation of the motor may cause a fire to occur depending on the nature of the dam-
age or malfunction.
Page 574 of 692

5748-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
●Fluid leaks under the vehicle.
(Water dripping from the air co nditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually points higher than nor-
mal.
●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, stumb ling 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 au thorized Lexus retailer or Lexus autho-
rized repairer, or any reliable re pairer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 580 of 692

5808-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
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 retailer
or Lexus authorized repairer, or any re liable repairer. The vehicle will become
extremely unstable during braking, and the ABS system may fail, which could cause an accident resulting in de ath or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy. When steering wheel operations are heavier than usual, grip the steering wheel firmly
and operate it using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precaution s. 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 adjust- ment, it is probable that you ha ve 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 adjust- ment, it is probable that you have a flat tire. Have the tire replaced by the nearest
authorized Lexus retailer or Lexus author ized repairer, or any reliable repairer.
●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 syst em 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.