2018 LEXUS RC350 engine

4066-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
Check the radiator, condenser and interc ooler radiator and clear away any for-
eign objects.
If any of the above parts are extremely dirt y or you are not sure of their condition,
have your vehicle inspecte d by your Lexus dealer.
WARNING
■When the engine is hot (RC350/RC300)
Do not remove the engine coolant reservoir cap, intercooler coolant reservoir cap and
coolant inlet cap. ( P. 530)
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
■When the engine is hot (RC F)
Do not remove the engine coolant reservoir cap. (P. 530)
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water and
antifreeze must be used to provide proper lubrication, corrosion protection and cool-
ing. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
Radiator, condenser and intercooler radiator (if equipped)
WARNING
■When the engine is hot
Do not touch the radiator, condenser or inte rcooler as they may be hot and cause seri-
ous injuries, such as burns.

4096-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
6
Maintenance and care
■Before recharging
When recharging, the battery produces hydrogen gas which is flammable and explosive.
Therefore, observe the following before recharging:
●If recharging with the battery installed on the vehicle, be sure to disconnect the ground
cable.
●Make sure the power switch on the charge r is off when connecting and disconnecting
the charger cables to the battery.
■After recharging/reconnecting the battery
The engine may not start. Follow the procedure below to initialize the system.
Shift the shift lever to P.
Open and close either door.
Restart the engine.
●Unlocking the doors using the smart access system with push-button start may not be
possible immediately after reconnecting the battery. If this happens, use the wireless
remote control or the mechanical key to lock/unlock the doors.
●Start the engine with the engine switch in ACCESSORY mode. The engine may not
start with the engine switch turned off. However, the engine will operate normally from
the second attempt.
●The engine switch mode is recorded by the vehicle. If the battery is disconnected and
reconnected, the vehicle will return the engi ne switch mode to the status it was in
before the battery was disconnected. Make su re to turn off the engine before discon-
necting the battery. Take extra care when connecting the battery if the engine switch
mode prior to the battery being disconnected is unknown.
If the system will not start even after mult iple attempts, contact your Lexus dealer.
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4106-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
WARNING
■Chemicals in the battery
Batteries contain 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 wo rking on or near the battery:
●Do not cause sparks by touching the battery terminals with tools.
●Do not smoke or light a match near the battery.
●Avoid contact with eyes, skin and clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when working near the battery.
●Keep children away from the battery.
■Where to safely charge the battery
Always charge the battery in an open area . Do not charge the battery in a garage or
closed room where there is insufficient ventilation.
■How to recharge the battery
Only perform a slow charge (5 A or less) . The 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 fe el pain or burning, get medical attention
immediately.
●If electrolyte gets on your clothes
It can soak through clothing on to your s kin. 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 emergenc y medical attention immedi-
ately.
NOTICE
■When recharging the battery
Never recharge the battery while the engine is running. Also, be sure all accessories
are turned off.

4116-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
6
Maintenance and care
If any washer does not work or the warning message appears on the multi-
information display, the washer tank may be empty. Add washer fluid.
Washer fluid
RC350/RC300 AWDRC300
RC F
WARNING
■When adding washer fluid
Do not add washer fluid when the engine is hot or running as washer fluid contains
alcohol and may catch fire if spilled on the engine etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle’s painted surfaces, as well as damaging
the pump leading to problems of the washer fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.

4146-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to th e specified cold tire inflation pressure
level. ( P. 548)
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 engine switch to IGNITION 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 engine switch in IGNITION ON mode and
then turn the engine switch off.
◆Registering ID codes
The tire pressure warning valve and tran smitter 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 your Lexus
dealer.
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4156-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
6
Maintenance and care
■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 properly repaired due to the size or location of
a cut or other damage
If you are not sure, consult your Lexus dealer.
■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 20 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 syst em does not replace routine tire inflation pressure checks.
Make sure to check tire inflat ion pressure as part of your routine of daily vehicle checks.
■When rotating the tires
Make sure that the engine switch is off. If the tires are rotated while the engine switch is in
IGNITION ON mode, the tire position information will not be updated.
If this accidentally occurs, either turn the engine switch to off and then to IGNITION ON
mode, or initialize the system after checking th at the tire pressure is properly adjusted.
■Low profile tires
Generally, low profile tires will wear more rapidly 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.

4176-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
6
Maintenance and care
■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.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects th e radio wave signals is installed.
• If there is a lot of snow or ice on the vehi cle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extr emely 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 st rong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phone or other wireless
communication device
If tire position information is not correctly displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions.
●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 afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment.
●If you have accidentally turned the engine swit ch 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 IG NITION 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 leve l when the tires are cold, and conduct initial-
ization again.
■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 your Lexus dealer.
●When operating the tire pres sure warning reset switch, the tire pressure warning light
does not blink 3 times.
●After carrying out the initializat ion procedure, the tire pressure warning light blinks for 1
minute then stays on after driving for 20 minutes.

4256-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
6
Maintenance and care
Turn the engine switch off.
Open the glove box. Lift up the side
with the stay, disconnect the stay
tabs and remove the partition by
pulling horizontally.
Press the tabs and remove the filter
cover.
Press the tabs and remove the filter
case.
Air conditioning filter
The air conditioning filter must be ch anged regularly to maintain air condi-
tioning efficiency.
Removal method
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