2020 LEXUS NX300h service

3406-2. Maintenance
LEXUS NX300h Owners Manual_USA_M78530_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 with-
out 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:

3426-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78530_en
6-3.Do-it-yourself maintenance
Do-it-yourself service pre-
cautions
If you perform maintenance by
yourself, be sure to follow the cor-
rect procedure as given in these
sections.
Maintenance
ItemsParts and tools
12-volt bat-
tery condition
( P.352)•Grease
•Conventional wrench
(for terminal clamp
bolts)
Brake fluid
level
( P.351)
• FMVSS No.116 DOT 3
or SAE J1703; FMVSS
No.116 DOT 4 or SAE
J1704 brake fluid
• Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/power
control unit
coolant level
( P.349)
•“Toyota Super Long Life
Coolant” or a similar
high quality ethylene gly-
col-based non-silicate,
non-amine, non-nitrite
and non-borate coolant
with long-life hybrid
organic acid technology
For the U.S.A.:
“Toyota Super Long Life
Coolant” is pre-mixed
with 50% coolant and
50% deionized water.
For Canada:
“Toyota Super Long Life
Coolant” is pre-mixed
with 55% coolant and
45% deionized water.
• Funnel (used only for adding coolant)
Engine oil
level
( P.347)
•“Toyota Genuine Motor
Oil” or equivalent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses
( P.370)Fuse with same amperage
rating as original
Light bulbs
( P.374)Bulb with same number
and wattage rating as orig-
inal
Headlight aimPhillips-head screw-driver
Radiator and
condenser
( P.350)
—
ItemsParts and tools

3616-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78530_en
6
Maintenance and care
istered by your Lexus dealer.
(  P.362)
■When replacing the 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
properly. After driving for about 20 min-
utes, the tire pressure warning light blinks
for 1 minute and stays on to indicate a sys-
tem malfunction.■The tire pressure warning system
must be initialized in the following
circumstances:
 When adjusting the tire inflation
pressure.
 When the tire inflation pressure is
changed such as when changing
traveling speed.
 When rotating the tires.
 When changing the tire.
When the tire pressure warning system
is initialized, the current tire inflation
pressure is set as the benchmark pres-
sure.
■How to initialize the tire pressure
warning system
1 Park the vehicle in a safe place and
turn the power switch off.
Initialization cannot be performed while
the vehicle is moving.
2 Adjust the tire inflation pressure to
the specified cold tire inflation pres-
sure level.
Make sure to adjust the tire pressure to the
specified cold tire infl ation pressure level.
The tire pressure warning system will oper-
ate based on this pressure level.
3 Turn the power switch to ON
mode.
NOTICE
■Repairing or replacing tires, wheels,
tire pressure warning valves, trans-
mitters and tire valve caps
●When removing or fitting the wheels,
tires or the tire pressure warning
valves and transmitters, contact your
Lexus dealer as the tire pressure warn-
ing valves and transmitters may be
damaged if not handled correctly.
●Make sure to install the tire valve caps.
If the tire valve caps are not installed,
water could enter the tire pressure
warning valves and the tire pressure
warning valves could be bound.
●When replacing tire valve caps, do not
use tire valve caps other than those
specified. The cap may become stuck.
■To avoid damage to the tire pressure
warning valves and transmitters
When a tire is repaired with liquid seal-
ants, the tire pressu re warning valve and
transmitter may not operate properly. If a
liquid sealant is used , contact your Lexus
dealer or other qualified service shop as
soon as possible. After use of liquid seal-
ant, make sure to re place the tire pres-
sure warning valve and transmitter when
repairing or replacing the tire. ( P.357,
366)
Initializing the tire pressure
warning system

3666-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78530_en
Use only Lexus wheel nuts and
wrenches designed for use with
your aluminum wheels.
 When rotating, repairing or chang-
ing your tires, check that the wheel
nuts are still tight after driving 1000
miles (1600 km).
 Be careful not to damage the alumi-
num wheels when using tire chains.
 Use only Lexus genuine balance
weights or equivalent and a plastic
or rubber hammer when balancing your wheels.
WARNING
●Never use an inner tube in a leaking
wheel which is designed for a tubeless
tire. Doing so may result in an acci-
dent, causing death or serious injury.
■Use of defective wheels prohibited
Do not use cracked or deformed wheels.
Doing so could cause the tire to leak air
during driving, possibly causing an acci-
dent.
NOTICE
■Replacing tire pressure warning
valves and transmitters
●Because tire repair or replacement
may affect the tire pressure warning
valves and transmitters, make sure to
have tires serviced by your Lexus
dealer or other qualified service shop.
In addition, make sure to purchase
your tire pressure warning valves and
transmitters at your Lexus dealer.
●Ensure that only ge nuine Lexus wheels
are used on your vehicle.
Tire pressure warning valves and trans-
mitters may not work properly with
non-genuine wheels.
Aluminum wheel precautions

3817-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
7-2.Steps to take in an emergency
If your vehicle needs to be
towed
If towing is ne cessary, we recom-
mend having your vehicle towed by
your Lexus dealer or commercial
towing service, using a wheel-lift
type truck or flatbed truck.
Use a safety chain system for all
towing, and abide by all state/pro-
vincial and local laws.
If towing your vehicle with a wheel-
lift type truck, use a towing dolly.
(  P.381, 382)
WARNING
Observe the following precautions.
Failure to do so may result in death or
serious injury.
■When towing the vehicle
Be sure to transport the vehicle with all
four wheels raised off the ground. If the
vehicle is towed with the tires contacting
the ground, the drivetrain or related
parts may be damaged, the vehicle may
fly off the truck, or electricity generated
by the operation of the motor may cause
a fire to occur depending on the nature
of the damage or malfunction.
■While towing
●When towing using a cables or chains,
avoid sudden starts, etc. which place
excessive stress on the towing eyelets,
cables or chains. The towing eyelets,
cables or chains may become dam-
aged, broken debris may hit people,
and cause serious damage.
●Do not turn the power switch off.
There is a possibility that the steering
wheel is locked and cannot be oper-
ated.
■Installing towing eyelets to the vehi-
cle
Make sure that towing eyelets are
installed securely.
If not securely installed, towing eyelets
may come loose during towing.
NOTICE
■To prevent damage to the vehicle
when towing using a wheel-lift type
truck
●Do not tow the vehicle from the rear
when the power switch is off. The
steering lock mechanism is not strong
enough to hold the front wheels
straight.
●When raising the vehicle, ensure ade-
quate ground clearance for towing at
the opposite end of the raised vehicle.
Without adequate clearance, the vehi-
cle could be damaged while being
towed.
■To prevent damage to the vehicle
when towing with a sling-type truck
Do not tow with a sling-type truck, either
from the front or rear.

3827-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
The following may indicate a problem
with your hybrid transmission. Contact
your Lexus dealer or commercial tow-
ing service before towing. ( P.381)
 The hybrid warning message shows
on the multi-information display and
the vehicle does not move.
 The vehicle makes an abnormal
sound.
Do not tow with a sling-type truck to
prevent body damage.
From the front
Use a towing dolly under the rear
wheels.
From the rear
Use a towing dolly under the front
wheels.
If your vehicle is transported by a flat-
bed truck, it should be tied down at the
locations shown in the illustration.
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 sling-type truck
Towing with a wheel-lift type
truck
Using a flatbed truck

4308-1. Specifications
LEXUS NX300h Owners Manual_USA_M78530_en
■Gasoline quality
In very few cases, driveability problems may
be caused by the brand of gasoline you are
using. If driveability problems persist, try
changing the brand of gasoline. If this does
not correct the problem, consult your Lexus
dealer.
■Recommendation of the use of gasoline
containing detergent additives
●Lexus recommends the use of gasoline
that contains detergent additives to avoid
the build-up of engine deposits.
●All gasoline sold in the U.S.A. contains
minimum detergent additives to clean
and/or keep clean intake systems, per
EPA’s lowest additive s concentration pro-
gram.
●Lexus strongly recommends the use of
Top Tier Detergent Gasoline. For more
information on Top Tier Detergent Gaso-
line and a list of marketers, please go to
the official websit e www.toptiergas.com.
■Recommendation of the use of low
emissions gasoline
Gasolines containing oxygenates such as
ethers and ethanol, as well as reformulated
gasolines, are available in some cities.
These fuels are typically acceptable for use,
providing they meet other fuel require-
ments. Lexus recommends these fuels, since the
formulations allow for reduced vehicle
emissions.
■Non-recommendation of the use of
blended gasoline
●Use only gasoline containing up to 15%
ethanol.
DO NOT use any flex-fuel or gasoline
that could contain more than 15% etha-
nol, including from
any pump labeled
E30 (30% ethanol ), E50 (50% etha-
nol ), E85 (85% ethanol ) (which
are only some examples of fuel contain-
ing more than 15% ethanol).
●If you use gasohol in your vehicle, be sure
that it has an octane rating no lower than
87.
●Lexus does not recommend the use of
gasoline containing methanol.
■Non-recommendation of the use of gas-
oline containing MMT
Some gasoline contains an octane enhanc-
ing additive called MMT (Methylcyclopen-
tadienyl Manganese Tricarbonyl).
Lexus does not recommend the use of gas-
oline that contains MMT. If fuel containing
MMT is used, your emission control system
may be adversely affected.
The malfunction indicator lamp on the
instrument cluster may come on. If this hap-
pens, contact your Lexus dealer for service.
■If your engine knocks
●Consult your Lexus dealer.
●You may occasionally notice light knock-
ing for a short time wh ile accelerating or
driving uphill. This is normal and there is
no need for concern.
Fuel information
You must only use unleaded gaso-
line in your vehicle.
Select octane rating 87 (Research
Octane Number 91) or higher. Use
of unleaded gasoline with an octane
rating lower than 87 may result in
engine knocking. Persistent knock-
ing can lead to engine damage.
At minimum, the gasoline you use
should meet the specifications of
ASTM D4814 in the U.S.A.
A
BC

4358-1. Specifications
LEXUS NX300h Owners Manual_USA_M78530_en
8
Vehicle specifications
Chafer
This information has been prepared in
accordance with regulations issued by
the National Highway Traffic Safety
Administration of the U.S. Department
of Transportation.
It provides the purchasers and/or pro-
spective purchasers of Lexus vehicles
with information on uniform tire quality
grading.
Your Lexus dealer will help answer any
questions you may have as you read this
information.
■DOT quality grades
All passenger vehicle tires must con-
form to Federal Safety Requirements in
addition to these grades. Quality
grades can be found where applicable
on the tire sidewall between tread
shoulder and maximum section width.
For example: Treadwear 200 Traction AA
Temperature A
■Treadwear
The treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would wear
one and a half (1 - 1/2) times as well on the
government course as a tire graded 100.
The relative performa nce of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm due to variatio ns in driving habits,
service practices and differences in road characteristics and climate.
■Traction AA, A, B, C
The traction grades, from highest to
lowest, are AA, A, B and C, and they
represent the tire’s ability to stop on
wet pavement as measured under con-
trolled conditions on specified govern-
ment test surfaces of asphalt and
concrete.
A tire marked C may have poor traction
performance.
Warning: The traction grade assigned to
this tire is based on braking (straight
ahead) traction tests and does not include
cornering (turning) traction.
■Temperature A, B, C
The temperature grades are A (the
highest), B, and C, representing the
tire’s resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Sustained high temperature can cause the
material of the tire to degenerate and
reduce tire life, and excessive temperature
can lead to sudd en tire failure.
Grade C corresponds to a level of perfor-
mance which all passenger car tires must
meet under the Fede ral Motor Vehicle
Safety Standard No. 109.
Grades B and A represent higher levels of
performance on the laboratory test wheel
than the minimum required by law.
Warning: The temperature grades for this
tire are established for a tire that is prop-
erly inflated and not overloaded.
Excessive speed, unde rinflation, or exces-
sive loading, either separately or in combi-
Uniform Tire Quality Grading
K