Page 481 of 640
4817-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
The 12-volt battery is located on the
left-hand side of luggage compart-
ment.
Remove the 12-volt battery cover.
Make sure that the 12-volt battery terminals are not corroded and that there are
no loose connections, cracks, or loose clamps.
Terminals
Hold-down clamp
12-volt battery
Location
Removing the 12-volt battery cover
Exterior
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2
Page 482 of 640

4827-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
The meanings of each caution symbol on the top of the 12-volt battery are as fol-
lows:
■Before recharging
When recharging, the 12-volt battery produc es hydrogen gas which is flammable and explosive. Therefore, observe the follo wing precautions before recharging:
●If recharging with the 12-volt battery installed on the vehicle, be sure to disconnect the
ground cable.
●Make sure the power switch on the charger is off when connecting and disconnecting
the charger cables to the 12-volt battery.
■After recharging/reconnecting the 12-volt battery
●The hybrid system may not start. Follow the procedure below to initialize the system.
Shift the shift lever to P.
Open and close any of the doors.
Restart the hybrid system.
●Unlocking the doors using the smart entry & start system may not be possible immedi- ately after reconnecting the 12-volt battery. If this happens, use the wireless remote control or the mechanical key to lock/unlock the doors.
●Start the hybrid system with the power switch in ACCESSORY mode. The hybrid sys-tem may not start with the power switch turned off. However, the hybrid system willoperate normally from the second attempt.
●The power switch mode is recorded by the vehicle. If the 12-volt battery is reconnected,the vehicle will return the power switch mode to the status it was in before the 12-volt battery was disconnected. Make sure to turn off the power switch before disconnecting
the 12-volt battery. Take extra care when connecting the 12-volt battery if the power switch mode prior to the 12-volt battery being disconnected is unknown.
If the system will not start even after multip le attempts at all the methods above, contact
any authorized Lexus dealer or repairer, or another duly qualified and equipped profes- sional.
Caution symbols
No smoking, no nakedflames, no sparks12-volt battery acid
Shield eyesNote operating instructions
Keep away from childrenExplosive gas
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4837-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
WARNING
■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 whil e 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 th ere is insufficient ventilation.
■How to recharge the 12-volt battery
Only perform a slow charge (5 A or less). 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 tothe nearest medical facility.
●If electrolyte gets on your skinWash the affected area thoroughly. If you f eel pain or burning, get medical attention immediately.
●If electrolyte gets on your clothesIt can soak through clothing on to your sk in. Immediately take off the clothing and fol- low the procedure above if necessary.
●If you accidentally swallow electrolyteDrink 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.
Page 484 of 640
4847-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
Check if the treadwear indicators are showing on the tires. Also check the tires
for uneven wear, such as excessive wear on one side of the tread.
Check the spare tire condition and pressure if not rotated.
New tread
Worn tread
Treadwear indicator
The location of treadwear indica tors is shown by a “TWI” or “” mark, etc., molded
into the sidewall of each tire.
Replace the tires if the treadwear indicators are showing on a tire.
Tires
Replace or rotate tires in accordance with maintenance schedules and
treadwear.
Checking tires
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Page 485 of 640
4857-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
Rotate the tires in the order shown.
To equalize tire wear and help extend tire life, Lexus recommends that tire rotation is
carried out approximately every 10000 km (6000 miles).
Do not fail to initialize the tire pressure warning system after tire rotation.
Tire rotation
Vehicles with front and rear tires of
the same size
Vehicles with front and rear tires of
differing sizes
FrontFront
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4867-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
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 screen display and a warning light. ( P. 539, 552)
●The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. ( P. 121)
The illustration used is intended as an example, and may differ from the image
that is actually displayed on the multi- information display.
◆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. 487)
Tire pressure warning system
Page 487 of 640

4877-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
◆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
traveling speed.
●When changing the tire size.
When the tire pressure warning system is initialized, the current tire inflation
pressure is set as the benchmark pressure.
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the power switch off.
Initialization cannot be perfor med while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation pressure
level. ( P. 604)
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 wa rning 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.
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2
3
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5
Page 488 of 640

4887-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
■When to replace your vehicle’s tires
Tires should be replaced if:
●The treadwear indicators are showing on a tire.
●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 prop erly 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 proper ly. After driving for about 10 minutes, the tire pressure warning light blinks for 1 minu te 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 re place routine tire inflation pressure checks.
Make sure to check tire inflation pressure as part of your routine of daily vehicle checks.
■When rotating the tires
Make sure that the power switch is off. If the tires are rotated while the power switch is in
ON mode, the tire position information will not be updated. If this accidentally occurs, either turn the power switch to off and then to ON mode, orinitialize the system after checking that the tire pressure is properly adjusted.
■Low profile tires
Generally, low profile tires will wear more ra pidly and tire grip performance will be reduced on snowy and/or icy roads when comp ared 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.
■If the tread on snow tires wears down below 4 mm (0.16 in.)
The effectiveness of the tires as snow tires is lost.