
4317-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)
■Situations in which the tire pressure warning system may not operate properly (vehi-
cles with a 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 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 registered
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 display, air-
port 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 (vehicles with a tire pressure warning system)
●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 inflation pres-
sure adjustment.
●If you have accidentally turned the engine switch off during initialization, it is not neces-
sary to press the reset switch again as initialization will restart automatically when the
engine switch has been turned to IGNITION 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 initial-
ization 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 con-
ditions 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.

4327-3. Do-it-yourself maintenance
IS250_EE(OM53C51E)
■When initialization of the tire pressure warning system has failed (vehicles with a tire
pressure warning system)
Initialization can be completed in a few minutes. However, in the following cases, the set-
tings 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 a 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 before-
hand.
For information about changing ID codes, ask any authorized Lexus dealer or repairer,
or another duly qualified and equipped professional.

4337-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)
■Certification for tire pressure warning system (vehicles with a tire pressure warning
system)

4347-3. Do-it-yourself maintenance
IS250_EE(OM53C51E)
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 dangerous han-
dling 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 compact spare
tire installed.
●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 (vehicles with a 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.

4357-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters and
tire valve caps (vehicles with a tire pressure warning system)
●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 quali-
fied 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 warning 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 (vehicles with a
tire pressure warning system)
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter 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 warn-
ing valve and transmitter when replacing the tire. (→P. 4 2 8 )
■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 16-inch tires)
Low profile tires may cause greater damage than usual to the tire wheel when sustain-
ing 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.

4387-3. Do-it-yourself maintenance
IS250_EE(OM53C51E)
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 (vehicles with a tire pressure warning system)
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 2 8 )
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

4397-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)
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 (vehicles with a tire pressure
warning system)
●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.

465
8When trouble arises
IS250_EE(OM53C51E)
8-1. Essential information
Emergency flashers...................466
If your vehicle has to
be stopped in an
emergency ................................. 4678-2. Steps to take in an
emergency
If your vehicle needs to
be towed .....................................468
If you think something is
wrong ............................................ 474
Fuel pump shut off system .......475
If a warning light turns
on or a warning buzzer
sounds........................................... 476
If a warning message is
displayed..................................... 482
If you have a flat tire
(vehicles with a
spare tire) ................................... 496
If you have a flat tire
(vehicles without a
spare tire) ................................... 507
If the engine will not start ..........521
If the shift lever cannot be
shifted from P............................ 523
If the electronic key does
not operate properly ............. 524
If the vehicle battery is
discharged ..................................527
If your vehicle overheats .......... 531
If the vehicle becomes
stuck ............................................. 534