maintenance LEXUS NX300 2020 Owner's Guide

3396-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
■Intercooler coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
■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 mix-
ture of 50% coolant and 50% deionized
water.
(Minimum temperature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture 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
dealer test the cap and check for leaks in
the cooling system.
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.
A
B
C
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir and the intercooler coolant reservoir
cap.
The cooling system may be under pres-
sure 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 cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser
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.

3406-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
■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.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703;
FMVSS No.116 DOT 4 or SAE J1704
brake fluid
Items
Clean funnel
■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.
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
WARNING
■When the electric cooling fans are
operating
Do not touch the engine compartment.
With the engine switch in IGNITION
ON mode, the electric cooling fans may
automatically start to run if the air condi-
tioning is on and/or the coolant tempera-
ture is high. Be sure the engine switch is
off when working near the electric cool-
ing fans or radiatorgrille.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your eyes,
flush the affected area with clean water
immediately.
If you still experience discomfort, 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 leve l in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Checking the battery
A
B

3416-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
■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 char-
ger is off when connecting and discon-
necting the charger cables to the battery.
■After recharging/reconnecting the bat-
tery
●The engine may not start. Follow the pro-
cedure below to initialize the system.
1
Shift the shift lever to P.
2
Open and close any of the doors.
3
Restart the engine.
●Unlocking the doors using the smart
access system with pu sh-button start may
not be possible immediately after recon-
necting 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 nor-
mally 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 st art even after multiple
attempts at all methods above, contact your
Lexus dealer.
WARNING
■Chemicals in the battery
Battery contains poisonous and corro-
sive sulfuric acid and may produce
hydrogen gas which is flammable and
explosive. To reduce the risk of death or
serious injury, take the following precau-
tions while working on or near the bat-
tery:
●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 sa fety 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.
■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 follow the procedure above if nec-
essary.

3426-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
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.
WARNING
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk.
Follow with milk of magnesia, beaten
raw egg or vegetable oil. Get emer-
gency medical attention immediately.
■When there is insufficient battery
fluid
Do not use if there is insufficient fluid in
the 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 acces-
sories are turned off.
■When adding distilled water
Avoid overfilling. Water spilled during
battery recharging may cause corrosion.
Checking and adding the washer
fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the engine
is hot or operating as washer fluid con-
tains 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 anti-
freeze 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 neces-
sary.
Refer to the freezing temperatures listed
on the label of the washer fluid bottle.

3436-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
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 indicators is
shown by a “TWI” or mark, etc.,
molded into the sidewall of each tire.
Replace the tires if the treadwear indica- tors are showing on a tire.
■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 repe atedly or cannot be
properly repaired due to the size or loca-
tion of a cut or other damage.
If you are not sure, consult with your Lexus
dealer.
■Tire life
Any tire over 6 years old must be checked
by a qualified technician even if it has sel-
dom or never been used or damage is not
obvious.
■Maximum load of tire
Check that the maximum load of the
replacement tire is greater than 1/2 of the
Gross Axle Weight Ratings (GAWR) of
either the front axle or the rear axle, which-
ever is greater.
For the GAWR, see the Certification Label.
For the maximum load of the tire, see the
load limit at maximum cold tire inflation
pressure mentioned on the sidewall of the
tire. ( P.418)
■Tire types
●Summer tires
Summer tires are high-speed perfor-
mance tires best suited to highway driv-
ing under dry conditions. Since summer
tires do not have the same traction per-
formance as snow tires, summer tires are
inadequate for driving on snow-covered
or icy roads. For driving on snow-covered
Tires
Replace or rotate tires in accor-
dance with maintenance schedules
and treadwear.
Checking tires
A
B
C

3446-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
roads or icy roads, the use of snow tires is
recommended. When installing snow
tires, be sure to replace all four tires.
●All season tires
All season tires are designed to provide
better traction in snow and to be ade-
quate for driving in most winter condi-
tions as well as for use year-round. All
season tires, however, do not have ade-
quate traction performance compared
with snow tires in heavy or loose snow.
Also, all season tires fall short in accelera-
tion and handling performance com-
pared with summer tires in highway
driving.
●Snow tires
For driving on snow-covered roads or icy
roads, we recommend using snow tires. If
you need snow tires,
select tires of the
same size, construction and load capacity
as the originally installed tires. Since your
vehicle has radial tires as original equip-
ment, make sure your snow tires also
have radial construction. Do not install
studded tires without first checking local
regulations for possible restrictions.
Snow tires should be installed on all
wheels. ( P.266)
■If the tread on snow tires wears down
below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is
lost.
Rotate the tires in the order shown.
To equalize tire wear and extend tire life,
Lexus recommends that tire rotation is car-
ried out at the same in terval as tire inspec-
tion.
Do not fail to initialize the tire pressure
warning system after tire rotation.
WARNING
■When inspecting or replacing tires
Observe the following precautions to
prevent accidents.
Failure to do so may cause damage to
parts of the drive train as well as danger-
ous handling 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.
●Do not tow if your vehicle has a com-
pact spare tire installed.
NOTICE
■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 cushion-
ing ability of the tires. In addition, driving
on rough roads may cause damage to
the tires themselves, as well as the vehi-
cle’s wheels and body.
■If tire inflation pressure of each tire
becomes low while driving
Do not continue driving, or your tires
and/or wheels may be ruined.
Tire rotation

3456-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
Front
Your vehicle is equipped with a tire
pressure warning system that uses tire
pressure warning valves and transmit-
ters 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.380)
 The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display.
■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.
■Situations in which the tire pressure
warning system may not operate prop-
erly
●In the following cases, the tire pressure
warning system may not operate prop-
erly.
• 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 the 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 extremely
higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter is used.
• If the ID code on the tire pressure warn- ing valves and transmitters is not regis-
tered in the tire pressure warning
computer.
●Performance may be af fected in the fol-
lowing situations.
• Near a TV tower, electric power plant, gas station, radio stat ion, large display,
airport or other fac ility 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 pr essure declines rap-
idly for example when a tire has burst, the
warning may not function.
Tire pressure warning system
A

3466-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
■Certification for tire pressure warning system
For vehicles sold in the U.S.A.

3476-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
For vehicles sold in Canada

3486-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
When replacing tires or wheels, tire
pressure warning valves and transmit-
ters 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 warn-
ing valve and transmitter ID codes reg-
WARNING
■Caution regarding interference with
electronic devices
●People with implantable cardiac pace-
makers, cardiac resynchronization
therapy-pacemakers or implantable
cardioverter defibrillators should not
come within 17.7 in. (450 mm) of the
tire pressure warning system initiators.
The radio waves may affect the opera-
tion of such devices.
●Users of any electrical medical device
other than implantable cardiac pace-
makers, cardiac resynchronization
therapy-pacemakers or implantable
cardioverter defibrillators should con-
sult the manufacturer of the device for
information about its operation under
the influence of radio waves.
Radio waves could have unexpected
effects on the operation of such medi-
cal devices.
Installing tire pressure warning
valves and transmitters