maintenance LEXUS RX450H 2020 Owner's Guide

5957-3. Do-it-yourself maintenance
7
Maintenance and care
RX350/RX350L_U
With the engine at operating temperature and turned off, check the oil level on
the dipstick.
■Checking the engine oil
Park the vehicle on level ground. Afte r warming up the engine and turning
off the engine, wait more than 5 minutes for the oil to drain back into the
bottom of the engine.
Holding a rag under the end, pull
the dipstick out.
Wipe the dipstick clean.
Reinsert the dipstick fully.
Holding a rag under the end, pull
the dipstick out and check the oil
level.
Low
Normal
Excessive
The shape of the dipstick may dif-
fer depending on the type of vehi-
cle or engine.
Wipe the dipstick and reinsert it fully.
Engine oil
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5967-3. Do-it-yourself maintenance
RX350/RX350L_U
■Adding engine oil
If the oil level is below or near the
low level mark, add engine oil of the
same type as that already in the
engine.
Make sure to check the oil type and prepare the items needed before adding
oil.
Remove the oil filler cap by turning it counterclockwise.
Add engine oil slowly, checking the dipstick.
Install the oil filler cap by turning it clockwise.
■Engine oil consumption
A certain amount of engine oil will be consumed while driving. In the following situations,
oil consumption may increase, and engine oil may need to be refilled in between oil
maintenance intervals.
●When the engine is new, for example directly after purchasing the vehicle or after
replacing the engine
●If low quality oil or oil of an inappropriate viscosity is used
●When driving at high engine speeds or with a heavy load, when towing, or when driving
while accelerating or decelerating frequently
●When leaving the engine idling for a long time, or when driving frequently through
heavy traffic
Engine oil selection P. 701
Oil quantity (Low  Full)1.9 qt. (1.8 L, 1.6 Imp. qt.)
ItemsClean funnel
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5977-3. Do-it-yourself maintenance
7
Maintenance and care
RX350/RX350L_U
■After changing the engine oil
The engine oil maintenance data should be reset. Perform the following procedures:
Select on the multi-information display. ( P. 97)
Press or of the meter control switch, select the “Vehicle Settings” then “Oil
Maintenance”. (To conf irm setting, press .)
Select the “Yes” and push .
A message is displayed on th e multi-information display.
WARNING
■Used engine oil
●Used engine oil contains potentially harm ful contaminants which may cause skin dis-
orders such as inflammation and skin cance r, so care should be taken to avoid pro-
longed and repeated contact. To remove used engine oil from your skin, wash
thoroughly with soap and water.
●Dispose of used oil and filters only in a sa fe and acceptable manner. Do not dispose of
used oil and filters in household trash, in sewers or onto the ground. Call your Lexus
dealer, service station or auto parts store for information concerning recycling or dis-
posal.
●Do not leave used engine oil within the reach of children.
NOTICE
■To prevent serious engine damage
Check the oil level on a regular basis.
■When replacing the engine oil
●Be careful not to spill engine oil on the vehicle components.
●Avoid overfilling, or the engine could be damaged.
●Check the oil level on the dipstick every time you refill the vehicle.
●Be sure the engine oil fille r cap is properly tightened.
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5987-3. Do-it-yourself maintenance
RX350/RX350L_U
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the engine is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL” line.
( P. 692)
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 F [-35 C])
Canada:
“Toyota Super Long Life Cool ant” is a mixture of 55% coolant and 45% deionized water.
(Minimum temperature: -44 F [-42C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir cap, drain cock and water
pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.
Coolant
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WARNING
■When the engine is hot
Do not remove the engine coolan t reservoir cap and radiator cap.
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.

5997-3. Do-it-yourself maintenance
7
Maintenance and care
RX350/RX350L_U
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer.
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 and condenser
WARNING
■When the engine is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

6007-3. Do-it-yourself maintenance
RX350/RX350L_U
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and prepare the necessary item.
■Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
Brake fluid
Fluid type FMVSS No.116 DOT 3 or SAE J1703 brake fluid
ItemsClean funnel
WARNING
■When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted surfaces.
If fluid gets on your hands or in your ey es, flush the affected area with clean water
immediately.
If you still experience di scomfort, see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear out or
when the fluid level in the accumulator is high.
If the reservoir needs frequent ref illing, there may be a serious problem.

6017-3. Do-it-yourself maintenance
7
Maintenance and care
RX350/RX350L_U
Check the battery as follows.
■Battery exterior
Make sure that the battery terminals are not corroded and that there are no
loose connections, cracks, or loose clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces hydrogen gas which is flammable and explosive.
Therefore, observe the following precautions 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 pr ocedure below to initialize the system.
Shift the shift lever to P.
Open and close any of the doors.
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 reconnected, the
vehicle will return the engine switch mode to the status it was in before the battery was
disconnected. Make sure to turn off the power before disconnect the battery. Take
extra care when connecting the battery if the engine switch mode prior to discharge is
unknown.
If the system will not start even after multip le attempts at all methods above, contact your
Lexus dealer.
Battery
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6027-3. Do-it-yourself maintenance
RX350/RX350L_U
WARNING
■Chemicals in the battery
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 wor king 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.
■When there is insufficient battery fluid
Do not use if there is insufficient fluid in th e battery. There is a possible danger that the
battery may explode.
NOTICE
■When recharging the battery
Never recharge the battery while the engine is running. Also, be sure all accessories
are turned off.
■When adding distilled water
Avoid overfilling. Water spilled during battery recharging may cause corrosion.

6037-3. Do-it-yourself maintenance
7
Maintenance and care
RX350/RX350L_U
If none of the washer does not work or
the “Windshield Washer Fluid Low”
appears on the multi-information dis-
play, the washer tank may be empty.
Add washer fluid.
Washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the engine is hot or operating 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.

6047-3. Do-it-yourself maintenance
RX350/RX350L_U
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.
Rotate the tires in the order shown.
To equalize tire wear and extend tire life,
Lexus recommends that tire rotation is
carried out at the same interval as tire
inspection.
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
Tire rotation
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Front