belt LEXUS NX300h 2021 Workshop Manual

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

3456-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_en
6
Maintenance and care
Tire inflation
pressure
( P.365)• Tire pressure gauge
• Compressed air source
Washer fluid
( P.353)
• Water or washer fluid
containing antifreeze
(for winter use)
• Funnel (used only for adding water or washer
fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Make sure that the “IGNITION ON”
on the multi-information display and
the “READY” indicator are both off.
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
power control unit, radiator, exhaust
manifold, etc. right after driving as they
may be hot. Oil and other fluids may
also be hot.
●Do not leave anything that may burn
easily, such as paper and rags, in the
engine compartment.
●Do not smoke, cause sparks or expose
an open flame to fuel. Fuel fumes are
flammable.
ItemsParts and tools■When working near the electric cool-
ing fans or radiator grille
Be sure the power switch is off.
With power switch in ON mode, the
electric cooling fans may automatically
start to run if the air conditioning is on
and/or the coolant temperature is high.
(  P.352)
■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

3586-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78578_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 insta lled 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.279)
■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

3817-1. Essential information
LEXUS NX300h Owners Manual_USA_M78578_en
7
When trouble arises
press it briefly 3 times or more in
succession.
5 Stop the vehicle in a safe place by
the road. 
Remove the seat belt first.
 If the door can be opened, open the
door and exit the vehicle.
 If the door can not be opened, open
the window using the power window
switch and exit the vehicle through
the window.
 If the window can not be opened
using the power window switch,
remain calm, wait until the water
level inside the vehicle rises to the
point that the water pressure inside
of the vehicle equals the water pres-
sure outside of the vehicle, and then
open the door and exit the vehicle.
WARNING
■If the hybrid system has to be turned
off while driving
Power assist for the steering wheel will
be lost, making th e steering wheel
heavier to turn. Decelerate as much as
possible before turning off the hybrid sys-
tem.
If the vehicle is trapped in
rising water
In the event the vehicle is sub-
merged in water, remain calm and
perform the following.
WARNING
■Using an emergency hammer* for
emergency escape
The front side wind ows and rear side
windows, as well as the rear window can
be shattered with an emergency ham-
mer
* used for emergency escape. How-
ever, an emergency hammer can not
shatter the windshield as it is laminated
glass.
*: Contact your Lexus dealer or after-
market accessory manufacturer for
further information about an emer-
gency hammer.

3847-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
The following may indicate a problem
with your hybrid transmission. Contact
your Lexus dealer or commercial tow-
ing service before towing. ( P.383)
 The hybrid system warning message
is shown on the multi-information
display and the vehicle does not
move.
 The vehicle makes an abnormal
sound.
From the front
Use a towing dolly under the rear
wheels.
From the rear
Use a towing dolly under the front
wheels.
When using a flat-bed truck to trans-
port the vehicle, use tire strapping
belts. Refer to the owner’s manual of
the flat-bed truck for the tire strapping
method.
NOTICE
■Recreational towing (behind motor
home, etc.)
Never dinghy tow your vehicle to pre-
vent causing serious damage to the
Hybrid AWD system and transmission.
(  P.173)
Situations when it is necessary to
contact dealers before towing
Towing with a wheel-lift type
truck
NOTICE
■Towing with a sling-type truck
Do not tow with a sling-type truck to pre-
vent body damage.
Using a flatbed truck

3907-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
■SRS warning light
■ABS warning light
■Electric power steering system warning light (warning buzzer)
Warning lightDetails/Actions
Indicates a malfunction in:
The SRS airbag system;
 The front passenger occupant classification system; or
 The seat belt pretensioner system
 Have the vehicle inspected by your Lexus dealer
immediately.
Warning lightDetails/Actions
(U.S.A.)
(Canada)
Indicates a malfunction in:
 The ABS; or
 The brake assist system
 Have the vehicle inspected by your Lexus dealer
immediately.
Warning lightDetails/Actions
(Yellow)
(Red)
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
 Have the vehicle inspected by your Lexus dealer
immediately.

3937-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
7
When trouble arises
■Low fuel level warning light
■Driver’s and front passenger’s seat belt reminder light (warning buzzer*)
*: Driver’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to alert the driver that hi s or her seat belt is
not fastened. Once the engine switch is turned to IGNITION ON mode, the buzzer
sounds. If the seat belt is still unfastened, the buzzer sounds intermittently for a certain
period of time after the ve hicle reaches a certain speed.
Front passenger’s seat belt warning buzzer:
The front passenger’s seat belt warning buzzer sounds to alert the front passenger that
his or her seat belt is not fastened. If the seat belt is unfastened, the buzzer sounds inter-
mittently for a certain peri od of time after the vehicle reaches a certain speed.
■Rear passengers’ seat belt reminder light*1 (warning buzzer*2)
*1: This light illuminates on the center panel. Re gardless of whether or not a rear passenger
is present, if the power switch is turned to ON mode with the rear seat belts unfastened,
this light will also illuminate for a certain period of time.
*2: Rear passengers’ seat belt warning buzzer: The rear passengers’ seat belt warning buzzer sounds to alert the rear passenger that
his or her seat belt is not fastened. If the seat belt is unfastened, the buzzer sounds inter-
mittently for a certain period of time, after th e seat belt is fastened and unfastened and
the vehicle reaches a certain speed.
Warning lightDetails/Actions
Indicates that remain ing fuel is approximately 2.2 gal. (8.4
L, 1.8 Imp.gal.) or less
 Refuel the vehicle.
Warning lightDetails/Actions
Warns the driver and/or front pa ssenger to fasten their seat
belts
 Fasten the seat belt.
If the front passenger’s seat is occupied, the front pas-
senger’s seat belt also need s to be fastened to make
the warning light (warning buzzer) turn off.
Warning lightDetails/Actions
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.

3957-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
7
When trouble arises
■Brake Override System/Drive-S tart Control warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■SRS warning light
This warning light system monitors the air-
bag sensor assembly, fr ont impact sensors,
side impact sensors (front door), side
impact sensors (rear), driver’s seat position
sensor, driver’s seat be lt buckle switch, front
passenger occupant cl assification system
(ECU and sensors), “AIR BAG ON” indi-
cator light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch,
driver’s seat belt pretensioner, front passen-
ger’s seat belt pretensioner and force lim-
iter, airbags, interconnecting wiring and
power sources. ( P.32)
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■Electric power steering system warning
light (warning buzzer)
When the 12-volt battery charge becomes
insufficient of the voltage temporarily drops,
the electric power steering system warning
light may come on and the warning buzzer
may sound.
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
Warning lightDetails/Actions
Brake Override System
Indicates that the accelerato r and brake pedals are being
depressed simultaneously, and the Brake Override System
is operating.
 Release the accelerator pedal and depress the brake
pedal.
Indicates a malfunction in the Brake Override System (with
warning buzzer)
 Have the vehicle inspected by your Lexus dealer
immediately.
Drive-Start Control
Indicates that the shift position was changed and Drive-
Start Control was operated wh ile depressing the accelera-
tor pedal. (with warning buzzer)
 Momentarily release th e accelerator pedal.
Indicates a malfunction in th e Drive-Start Control system
(with warning buzzer)
 Have the vehicle inspected by your Lexus dealer
immediately.

4187-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
■“Engine Coolant Temp High” is
shown on the multi-information dis-
play
1 Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2 If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has cooled
down sufficiently, inspect the hoses
WARNING
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.
■When exchanging the 12-volt battery
After exchanging, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the exchanged 12-
volt battery. If not properly installed,
gases (hydrogen) may leak into the vehi-
cle interior, and there is the possible dan-
ger of the gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.84)
enters the red zone, or a loss of
hybrid system power is experi-
enced. (For example, the vehicle
speed does not increase.)
 “Engine Coolant Temp High” or
“Hybrid System Overheated” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures

4258-1. Specifications
LEXUS NX300h Owners Manual_USA_M78578_en
8
Vehicle specifications
This number is also stamped under the
right-hand front seat.
■Engine number
The engine number is stamped on the
engine block as shown.
Engine
Model2.5 L 4-cylinder (2AR-FXE)
Type4-cylinder in line, 4-cycle, gasoline
Bore and stroke3.54  3.86 in. (90.0  98.0 mm)
Displacement152.2 cu.in. (2494 cm3)
Valve clearance (engine cold)Automatic adjustment
Drive belt tensionAutomatic adjustment
Fuel
Fuel typeUnleaded gasoline only
Octane Rating87 (Research Octane Number 91) or higher
Fuel tank capacity (Reference)14.8 gal. (56 L, 12.3 Imp.gal.)