2020 LEXUS NX300 air condition

3566-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
■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 operational 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

3827-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
The light will go off after several driving
trips.
If the light does not go off even after several
trips, contact your Lexus dealer as soon as
possible.
■When the tire pressure warning light
comes on
Inspect the appearance of the tire to check
that the tire is not punctured.
If the tire is punctured: P.387
If the tire is not punctured:
Carry out the following procedure after the
tire temperature has lowered sufficiently.
●Check the tire inflation pressure and
adjust to the appropriate level.
●If the warning light does not go out even
after several minutes, check that the tire
inflation pressure is at the specified level
and carry out initialization. ( P.349)
The warning light may come on again if the
above operations are conducted without
first allowing the tire temperature to lower
sufficiently.
■The tire pressure warning light may
come on due to natural causes
The tire pressure warning light may come
on due to natural causes such as natural air
leaks and tire inflation pressure changes
caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with
a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warn-
ing light will not turn off even though the flat
tire has been replaced with the spare tire.
Replace the spare tire with the repaired tire
and adjust the tire inflation pressure. The
tire pressure warning lig ht will go off after a
few minutes.
■Conditions that the tire pressure warn-
ing system may not function properly
 P.345
■If the tire pressure warning light fre-
quently comes on after blinking for 1
minute
If the tire pressure wa rning light frequently comes on after blinking
for 1 minute when
the engine switch is turned to IGNITION
ON mode, have it checked by your Lexus
dealer.
■Warning buzzer
In some cases, the buzzer may not be heard
due to being in a noisy location or audio
sound.
WARNING
■If both the ABS and the brake system
warning lights remain on
Stop your vehicle in a safe place immedi-
ately and contact your Lexus dealer. The
vehicle will become extremely unstable
during braking, and the ABS system may
fail, which could cause an accident
resulting in death or serious injury.
■When the electric power steering
system warning light comes on
When the light comes on yellow, the
assist to the power st eering is restricted.
When the light comes on red, the assist
to the power steering is lost and handling
operations of the steering wheel become
extremely heavy. When steering wheel
operations are heavier than usual, grip
the steering wheel firmly and operate it
using more force than usual.
■If the tire pressure warning light
comes on
Be sure to observe the following precau-
tions. Failure to do so could cause a loss
of vehicle control and result in death or
serious injury.
●Stop your vehicle in a safe place as
soon as possible. Adjust the tire infla-
tion pressure immediately.
WARNING
●If the tire pressure warning light comes
on even after tire inflation pressure
adjustment, it is prob able that you have
a flat tire. Check the tire s. If a tire is flat,
change it with the spare tire and have
the flat tire repaired by the nearest
Lexus dealer.

4037-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
7
When trouble arises
1Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the engine.
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 engine has cooled down
sufficiently, inspect the hoses and
WARNING
●Always wash your hands after handling
the battery support, terminals, and
other battery-related parts.
●Do not allow children near the battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or engine drive
belt.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.79)
enters the red zone, or a loss of
engine power is experienced.
(For example, the vehicle speed
does not increase.)
 “Engine Coolant Temp High” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures

4057-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
7
When trouble arises
6Start the engine and turn the air
conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7If the fans are not operating:
Stop the engine immediately and
contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8
Check if “Engine Coolant Temp
High” is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the engine and contact your
Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Lexus dealer.
WARNING
■To prevent an accident or injury when
inspecting under the hood of your
vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.
●Do not touch within the engine com-
partment or get close when the cool-
ing fan is operating. Body parts,
clothes, etc., may get caught and lead
to an accident, resulting in serious
injury. The cooling fan operates auto-
matically at times when the air condi-
tioner is operating and times when the
coolant temperatures are high. Also, it
may operate for several minutes even
after the engine switch is turned off.
●Keep hands and clothing (especially a
tie, a scarf or a muffler) away from the
fans and belts. Failure to do so may
cause the hands or clothing to be
caught, resulting in serious injury.
●Do not loosen the coolant reservoir
cap while the engine and radiator are
hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has
cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can
cause damage to the engine.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust,
etc.).
●Do not use any coolant additive.

4228-1. Specifications
LEXUS NX300 Owners Manual_USA_M78389_en
nation, can cause heat buildup and
possible tire failure.
Glossary of tire terminology
Tire related
termMeaning
Cold tire infla-
tion pressure
Tire pressure when the
vehicle has been parked
for three hours or more, or
has not been driven more
than 1 mile or 1.5 km under
that condition
Maximum
inflation pres-
sureThe maximum cold inflated
pressure to which a tire
may be inflated, shown on
the sidewall of the tire
Recom-
mended infla-
tion pressureCold tire inflation pressure
recommended by a manu-
facturer
Accessory
weight
The combined weight (in
excess of thos e standard
items which may be
replaced) of transmission,
power steering, power
brakes, power windows,
power seats, radio and
heater, to the extent that
these items are available as
factory-installed equip-
ment (whether installed or
not)
Curb weight
The weight of a motor
vehicle with standard
equipment, including the
maximum capacity of fuel,
oil and coolant, and if so
equipped, air conditioning
and additional weight
optional engine
Maximum
loaded vehi-
cle weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options
weight
Normal occu-
pant weight
150 lb. (68 kg) times the
number of occupants
specified in the second
column of Table 1
* that fol-
lows
Occupant
distribution
Distribution of occupants
in a vehicle as specified in
the third column of Table 1
*
below
Production
options
weight
The combined weight of
installed regu lar produc-
tion options weighing over
5 lb. (2.3 kg) in excess of
the standard items which
they replace, not previ-
ously considered in curb
weight or accessory
weight, including heavy
duty brakes, ride levelers,
roof rack, heavy duty bat-
tery, and special trim
Rim
A metal support for a tire
or a tire and tube assembly
upon which the tire beads
are seated
Rim diameter
(Wheel diam-
eter)Nominal diameter of the
bead seat
Rim size des-
ignationRim diameter and width
Tire related termMeaning

4328-2. Customization
LEXUS NX300 Owners Manual_USA_M78389_en
■Head-up display* ( P.88)
*:If equipped
■Automatic air conditioning system ( P.279)
■Power windows ( P.138)
FunctionDefault settingCustomized set-
ting
Route guidance to destina-
tionOnOff———O
Driving assist system informa-
tionOnOff———O
Audio system operation sta-
tusOnOff———O
Lane displayOnOff———O
FunctionDefault settingCustomized set-ting
Switching between outside
air and recirculated air mode
linked to “AUTO” switch
operation
OnOffO—O—
A/C Auto switch operationOnOffO—O—
FunctionDefault settingCustomized set-ting
Mechanical key linked opera-
tionOffOn——O—
Wireless remote control
linked open operationOffOn——O—
ABCD
ABCD
ABCD

4378-2. Customization
LEXUS NX300 Owners Manual_USA_M78389_en
8
Vehicle specifications
■Driving mode select switch ( P.258)
■Eco mode (P.258)
■Vehicle customization
●When the speed linked d oor locking function and shift po sition linked door locking func-
tion are both on, the door lock operates as follows.
• When shifting the shift lever to any position other than P, all the doors will be locked.
• If the vehicle is started with all the doors locked, the speed linked door locking function
would not operate.
• If the vehicle is started with any door unlock ed, the speed linked door locking function will
operate.
●When the smart access system with push-button start is off, smart door unlocking cannot
be customized.
●When the doors remain closed after unlock ing the doors and the automatic door lock
function is activat ed, the signals will be generated in accordance with the Operation sig-
nal (buzzer) and the Operation sign al (emergency flashers) settings.
■In the following situations, customize mode in which the settings can be changed
through the multi-information display will automatically be turned off.
●A warning message appears after the cu stomize mode screen is displayed.
●The engine switch is turned off.
●The vehicle begins to move while the customize mode screen is displayed.
FunctionDefault settingCustomized set-
ting
Powertrain control in custom
modeNormalPowerO———Eco
Chassis control in custom
modeNormalSportO———
Air conditioning operation in
custom modeNormalEcoO———
FunctionDefault settingCustomized set-ting
Heating/coolin g operation
minimized in Eco modeOnOff——O—
ABCD
ABCD

LEXUS NX300 Owners Manual_USA_M78389_en
455Alphabetical Index
Alphabetical Index
A
A/C ................................................................... 279
Air conditioning filter ...............................355
Automatic air conditioning system ... 279
Micro dust and pollen filter................... 284
ABS (Anti-lock Brake System).............. 260 Function ..........................................................260
S-FLOW mode.......................................... 284
Warning light ................................................377
Active Sound Control (ASC) .................. 177
Adaptive Variable Suspension system (AVS) .............................................................. 261
AFS (Adaptive Front-lighting System) 180
Air conditioning filter ................................. 355
Air conditioning system ............................ 279 Air conditioning filter ...............................355
Automatic air conditioning system ... 279
Micro dust and pollen filter................... 284
S-FLOW mode.......................................... 284
Airbags ............................................................... 32 Airbag operating conditions................... 34
Airbag precautions for your child .........37
Airbag warning light ................................ 376
Correct driving posture ............................ 25
Curtain shield airbag operating condi-tions .................................................................. 34
Curtain shield airbag precautions ........37
Front passenger occupant classification system ............................................................... 41
General airbag precautions ....................37
Locations of airbags.....................................32
Modification and disposal of airbags . 40
Seat cushion airbag ......................................32
Side airbag operating conditions ......... 34
Side airbag precautions .............................37
Side and curtain shield airbags operating conditions...................................................... 34 Side and curtain shield airbags precau-
tions .................................................................. 37
SRS airbag instruct ions for Canadian
owners ......................................................... 442
SRS airbags...................................................... 32
SRS warning light....................................... 376
Alarm ................................................................... 70 Alarm................................................................... 70
Warning buzzer .........................................375
Anchor brackets ..................................... 57, 58
Antenna (Smart access system with push- button start) ................................................... 116
Anti-lock brake system (ABS) ............... 260 Function ......................................................... 260
Warning light ............................................... 377
Approach warning........................................231
Armrest............................................................308
ASC (Active Sound Control) .................. 177
Assist grips .....................................................308
Automatic air conditioning system ...... 279 Air conditioning filter............................... 355
Automatic air conditioning system ... 279
Micro dust and pollen filter ...................284
S-FLOW mode ..........................................284
Automatic headlight leveling system .... 179
Automatic High Beam ................................. 181
Automatic light control system................ 179
Auxiliary box.................................................. 294
B
Back door ........................................................ 104 Wireless remote control ......................... 105
Back-up lights Replacing light bulbs ................................362