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4497-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53C61E)
CAUTION
■Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may produce
hydrogen gas which is flammable and explosive. To reduce the risk of death or serious
injury, take the following precautions while working on or near the 12-volt battery:
●Do not cause sparks by touching the 12-volt battery terminals with tools.
●Do not smoke or light a match near the 12-volt battery.
●Avoid contact with eyes, skin and clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when working near the 12-volt battery.
●Keep children away from the 12-volt battery.
■Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charge the 12-volt battery in
a garage or closed room where there is insufficient ventilation.
■How to recharge the 12-volt battery
Only perform a slow charge (4 A — 5 A). The 12-volt battery may explode if charged at
a quicker rate.
■Emergency measures regarding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medical
attention. If possible, continue to apply water with a sponge or cloth while traveling to
the nearest medical facility.
●If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical attention
immediately.
●If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the clothing and fol-
low the procedure above if necessary.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention immedi-
ately.
■When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may cause gas (hydro-
gen) to enter the passenger compartment, causing a fire or explosion.
For replacement of the 12-volt battery, contact any authorized Lexus dealer or repairer,
or another duly qualified and equipped professional.
NOTICE
■When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating. Also, be sure
all accessories are turned off.
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Page 450 of 612
4507-3. Do-it-yourself maintenance
IS300h_EE(OM53C61E)
New tread
Treadwear indicator
Wo r n t r e a d
The location of treadwear indicators is
shown by the “TWI” or “∆” marks, etc.,
molded on the sidewall of each tire.
Check spare tire condition and pressure
if not rotated.
Rotate the tires in the order shown.
To equalize tire wear and help extend tire life, Lexus recommends that tire rota-
tion is carried out approximately every 10000 km (6000 miles).
Do not fail to initialize the tire pressure warning system after tire rotation.
Tires
Replace or rotate tires in accordance with maintenance schedules and tread-
wear.
Checking tires
1
2
3
Tire rotation
XVehicles with front and rear tires of
the same size XVehicles with front and rear tires of
differing sizes
FrontFront
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Page 451 of 612

4517-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53C61E)
Your vehicle is equipped with a tire pressure warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure before
serious problems arise.
If the tire pressure drops below a predetermined level, the driver is warned by a
warning light. (→P. 505)
◆Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and transmitters
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. 4 5 2 )
◆Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following circum-
stances:
●When rotating the tires.
●When the tire inflation pressure is changed such as when changing travel-
ing 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
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4527-3. Do-it-yourself maintenance
IS300h_EE(OM53C61E)
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the power switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation pressure
level. (→P. 5 6 8 )
Make sure to adjust the tire pressure to the specified cold tire inflation pressure
level. The tire pressure warning system will operate based on this pressure level.
Turn the power switch to ON mode.
Press and hold the tire pressure
warning reset switch until the tire
pressure warning light blinks
slowly 3 times.
Wait for a few minutes with the power switch in ON mode and then turn
the power switch off.
◆Registering ID codes
The tire pressure warning valve and transmitter is equipped with a unique ID
code. When replacing a tire pressure warning valve and transmitter, it is nec-
essary to register the ID code. Have the ID code registered by any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional.
1
2
3
4
5
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4537-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53C61E)
■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 fabric, and
bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or location of
a cut or other damage
If you are not sure, consult any authorized Lexus dealer or repairer, or another duly qual-
ified 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 malfunc-
tion.
■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 appro-
priate 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.
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4547-3. Do-it-yourself maintenance
IS300h_EE(OM53C61E)
■Situations in which the tire pressure warning system may not operate properly
●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
●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 power switch off during initialization, it is not neces-
sary to press the reset switch again as initialization will restart automatically 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 initial-
ization again.
■Warning performance of the tire pressure warning system
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.
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4557-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53C61E)
■When initialization of the tire pressure warning system has failed
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
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.
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Page 456 of 612
4567-3. Do-it-yourself maintenance
IS300h_EE(OM53C61E)
■Certification for tire pressure warning system
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