2021 LEXUS NX300h battery

3396-2. Maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
6
Maintenance and care
6-2.Maintenance
■Repair and replacement
It is recommended that genuine Lexus parts
be used for repairs to ensure performance
of each system. If non-Lexus parts are used
in replacement or if a repair shop other than
a Lexus dealer perfor ms repairs, confirm
the warranty coverage.
■Allow inspection and repairs to be per-
formed by a Lexus dealer
●Lexus technicians are well-trained spe-
cialists and are kept up to date with the
latest service information. They are well
informed about the operation of all sys-
tems on your vehicle.
●Keep a copy of the repa ir order. It proves
that the maintenance that has been per-
formed is under warra nty coverage. If any
problem should arise while your vehicle is
under warranty, your Lexus dealer will
promptly take care of it.
General maintenance should be per-
formed on a daily basis. This can be
done by yourself or by a Lexus dealer.
Scheduled maintenance should be
performed at specified intervals
according to the maintenance sched-
ule.
For details about ma intenance items and
schedules, refer to the “Warranty and Ser-
vice Guide”, “Owner’s Manual Supple-
ment” or “Scheduled Maintenance”.
■Resetting the message indicating main-
tenance is required (Except for Can-
ada)
After the required maintenance is pre-
formed according to the maintenance
schedule, please reset the message.
To reset the message, follow the procedures
described below:
1 Press or of the meter control
switches and select .
Maintenance requirements
To ensure safe and economical driv-
ing, day-to-day care and regular
maintenance are essential. It is the
owner’s responsibility to perform
regular checks. Lexus recommends
the following maintenance:
WARNING
■If your vehicle is not properly main-
tained
Improper maintenanc e could result in
serious damage to the vehicle and possi-
ble death or serious injury.
■Handling of the 12-volt battery
●Engine exhaust, some of its constitu-
ents, and a wide variety of automobile
components contain or emit chemicals
known to the State of California to
cause cancer and birth defects and
other reproductive harm. Work in a
well ventilated area.
●Oils, fuels and fluids contained in vehi-
cles as well as waste produced by
component wear contain or emit
chemicals known to the State of Cali-
fornia to cause cancer and birth
defects or other re productive harm.
Avoid exposure and wash any affected
area immediately.
●12-volt Battery post s, terminals and
related accessories contain lead and
lead compounds which are known to
cause brain damage. Wash your hands
after handling. ( P.354)
General maintenance
Scheduled maintenance

3416-2. Maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
6
Maintenance and care
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connections.
( P.354)
Vehicle interior
ItemsCheck points
Accelerator
pedal
The accelerator pedal
should move smoothly
(without uneven pedal
effort or catching).
Hybrid trans-
mission “Park”
mechanismWhen parked on a slope
and the shift lever is in P, is
the vehicle securely
stopped?
Brake pedal
• Does the brake pedal
move smoothly?
• Does the brake pedal have appropriate clear-
ance from the floor?
• Does the brake pedal have the correct amount
of free play?
Brakes
• The vehicle should not pull to one side when
the brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should not get too close to the
floor when the brakes
are applied.
Head
restraintsDo the head restraints
move smoothly and lock
securely?
Indica-
tors/buzzersDo the indicators and
buzzers function properly?
LightsDo all the lights come on?
Parking brake
• Does the parking brake switch operate nor-
mally?
• When parked on a slope and the parking brake is
on, is the vehicle
securely stopped?
Seat belts
• Do the seat belts oper-ate smoothly?
• The seat belts should not be damaged.
SeatsDo the seat controls oper-
ate properly?
Steering
wheel
• Does the steering wheel rotate smoothly?
• Does the steering wheel have the correct amount
of free play?
•There should not be any strange sounds coming
from the steering wheel.
Vehicle exterior
ItemsCheck points
DoorsDo the doors operate
smoothly?
Engine hoodDoes the engine hood lock
system work properly?
Fluid leaks
There should not be any
signs of fluid leakage after
the vehicle has been
parked.
ItemsCheck points

3426-2. Maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
The OBD system determines that a
problem exists somewhere in the emis-
sion control system. Your vehicle may
not pass the I/M test and may need to
be repaired. Contact your Lexus
dealer to service the vehicle.
When the 12-volt battery is discon-
nected or discharged
Readiness codes that are set during
ordinary driving are erased.
Also, depending on your driving
habits, the readiness codes may not
be completely set.
 When the fuel tank cap is loose
The malfunction indicator lamp
comes on indicating a temporary
malfunction and your vehicle may
not pass the I/M test.
Tires
• Is the tire inflation pres-
sure correct?
• The tires should not be damaged or excessively
worn.
• Have the tires been rotated according to the
maintenance schedule?
• The wheel nuts should not be loose.
Windshield
wipers/rear
window wiper
•The wiper blades should not show any signs of
cracking, splitting, wear,
contamination or defor-
mation.
•The wiper blades should clear the wind-
shield/rear window
without streaking or
skipping.
ItemsCheck pointsEmission inspection and
maintenance (I/M) pro-
grams
Some states have vehicle emission
inspection programs which include
OBD (On Board Diagnostics)
checks. The OBD system monitors
the operation of the emission con-
trol system.
If the malfunction indicator lamp
comes on
Your vehicle may not pass the
I/M test in the following situa-
tions:

3486-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
Fuse box (P.371)
Engine coolant reservoir ( P.351)
Engine oil filler cap ( P.350)
Power control unit coolant reservoir ( P.352)
Brake fluid reservoir ( P.353)
Radiator ( P.352)
Condenser ( P.352)
Electric cooling fans
Engine oil level dipstick ( P.349)
Washer fluid tank ( P.353)
■12-volt battery
 P.354
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J

3546-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
The 12-volt battery is located in the left-
hand side of luggage compartment.
■Before recharging
When recharging, the 12-volt battery pro-
duces hydrogen gas which is flammable
and explosive. Therefore, observe the fol-
lowing precautions before recharging:
●If recharging with the 12-volt battery
installed on the vehicle, be sure to discon-
nect the ground cable.
●Make sure the power switch on the char-
ger is off when connecting and discon-
necting 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 sys-
tem.
1 Shift the shift lever to P.
2 Open and close any of the doors.
3 Restart the hybrid system.
●Unlocking the doors using the smart
access system with pu sh-button start may
not be possible immediately after recon-
necting the 12-volt battery. If this hap-
pens, 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
WARNING
■When adding washer fluid
Do not add washer fluid when the hybrid
system 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 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.
12-volt battery
Location

3556-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
6
Maintenance and care
hybrid system may not start with the
power switch turned off. However, the
hybrid system will operate normally from
the second attempt.
●The power switch mode is recorded by
the vehicle. If the 12-volt battery is recon-
nected, 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 before
disconnect the 12- volt battery. Take extra
care when connecting the 12-volt battery
if the power switch mode prior to dis-
charge 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 12-volt battery
The 12-volt battery contains poisonous
and corrosive sulfuric acid and may pro-
duce hydrogen gas which is flammable
and explosive. To reduce the risk of death
or serious injury, take the following pre-
cautions 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 bat-
tery 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.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk.
Get emergency medical attention
immediately.
■When handling the 12-volt battery
 P.417
■When disconnecting the 12-volt bat-
tery
Do not disconnect the negative (-) termi-
nal on the body side as shown. The dis-
connected negative (-) terminal may
touch the positive (+) terminal, which
may cause a short and result in death or
serious injury.

3566-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
1Lift the deck board and attach the
hook. ( P.309)
2 Remove the left side deck board.
3 Remove the cover after removing
the chip.
Press
Pull out
Make sure that the 12-volt battery ter-
minals are not corroded and that there
are no loose connections, cracks, or loose clamps.
Terminals
Hold-down clamp
Insert the left side auxiliary box.
1 Push up center position
2 Insert
3 Press
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.
Removing the 12-volt battery
maintenance cover
Exterior
A
B
Installing the 12-volt battery
maintenance cover
A
B

3696-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
6
Maintenance and care
■When the card key battery needs to be
replaced (if equipped)
The battery for the card key is available only
at Lexus dealers. Your Lexus dealer can
replace the battery for you.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-but-
ton start and wireless remote control will
not function properly.
●The operationa l range will be reduced.
Prepare the following before replacing
the battery:
Flathead screwdriver
 Lithium battery CR2032
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus
dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent
type recommended by the manufacturer.
●Dispose of used batteries according to
the local laws.
NOTICE
■When using the air conditioning sys-
tem
Make sure that a filter is always installed.
Using the air conditioning system without
a filter may cause damage to the system.
Electronic key battery
Replace the battery with a new one
if it is depleted.
Items to prepare