2018 LEXUS NX300h cooling

631-2. Hybrid system
LEXUS NX300h Owners Manu-
al_USA_OM78212U 1
For safety and security ■
Sounds and vibrations specific to a
hybrid vehicle
There may be no engine sound or vibration
even though the vehicle is able to move with
the “READY” indicator is illuminated. For
safety, make sure to sh ift the shift lever to P
and apply the parking brake when parked.
The following sounds or vibrations may
occur when the hybrid system is operating
and are not a malfunction: ●
Motor sounds may be heard from the
engine compartment.●
Sounds may be heard from the hybrid
battery (traction battery) behind the rear
seats when the hybrid system starts or
stops.●
Relay operating sounds such as a snap or
soft clank will be emitted from the hybrid
battery (traction batter y), behind the rear
seats, when the hybrid system is started
or stopped.●
Sounds from the hybrid system may be
heard when the back door is open.●
Sounds may be heard from the transmis-
sion when the gasoline engine starts or
stops, when driving at low speeds, or
during idling.●
Engine sounds may be heard when
accelerating sharply.●
Sounds may be heard due to regenera-
tive braking when the brake pedal is
depressed or as the accelerator pedal is
released.●
Vibration may be felt when the gasoline
engine starts or stops.●
Cooling fan sounds may be heard from
the air intake vents under the rear seats.
■
Maintenance, repair, recycling, and dis-
posal
Contact your Lexus dealer regarding main-
tenance, repair, recycling and disposal. Do
not dispose of the vehicle yourself.
■
Customization
Settings (e.g. on/off operation of the EV
indicator) can be changed.
(Customizable features: → P.419) When driving with the gasoline engine
stopped, a sound, which changes in
accordance with the driving speed, will
be played in order to warn people
nearby of the vehicle’s approach. The
sound will stop when the vehicle speed
exceeds approximately 15 mph (25
km/h). ■
Vehicle proximity notification system
In the following cases, the vehicle proximity
notification system may be difficult for sur-
rounding people to hear. ●
In very noisy areas ●
In the wind or the rain
Also, as the vehicle proximity notification
system is installed on the front of the vehicle,
it may be more difficult to hear from the rear
of the vehicle compared to the front.Vehicle proximity notification
system

66 1-2. Hybrid system
LEXUS NX300h Owners Manu-
al_USA_OM78212U The cooling air intake and discharge
vents for the hybrid battery (traction
battery) are located under the rear
seats and between the rear seats and
deck board, respectively. If the air
intake vents are blocked, it could lead
to a reduction in hybrid battery (trac-
tion battery) output. The hybrid battery (traction battery) out-
put will not be reduced, even if the space
between the upper part of the air dis-
charge vents on the back of the rear seat
and deck board is blocked with luggage,
etc.WARNING●
If your vehicle needs to be towed, do
so with four wheels raised. If the
wheels connected to the electric
motor (traction motor) are on the
ground when towing, the motor may
continue to generate electricity. This
may cause a fire. ( → P.360)●
Carefully inspect the ground under the
vehicle. If you find that liquid has
leaked onto the ground, the fuel sys-
tem may have been damaged. Leave
the vehicle as soon as possible.■
Hybrid battery (traction battery)●
Never resell, hand over or modify the
hybrid battery. To prevent accidents,
hybrid batteries that have been
removed from a disposed vehicle are
collected through Lexus dealers. Do
not dispose of the battery yourself.
Unless the battery is properly collected,
the following may occur, resulting in
death or serious injury:
• The hybrid battery may be illegally dis-
posed of or dumped, and it is hazard-
ous to the environment or someone
may touch a high voltage part, result-
ing in an electric shock.
• The hybrid battery is intended to be
used exclusively with your hybrid vehi-
cle. If the hybrid battery is used outside
of your vehicle or modified in any way,
accidents such as electric shock, heat
generation, smoke generation, an
explosion and electrolyte leakage may
occur.
When reselling or handing over your
vehicle, the possibility of an accident is
extremely high because the person
receiving the vehicle may not be aware
of these dangers. ●
If your vehicle is disposed of without
the hybrid battery having been
removed, there is a danger of serious
electric shock if hi gh voltage parts,
cables and their connectors are
touched. In the event that your vehicle
must be disposed of, the hybrid battery
must be disposed of by your Lexus
dealer or a qualified service shop. If
the hybrid battery is not disposed of
properly, it may cause electric shock
that can result in death or serious
injury.
Hybrid battery (traction bat-
tery) air intake and discharge
vents

671-2. Hybrid system
LEXUS NX300h Owners Manu-
al_USA_OM78212U 1
For safety and security
Air intake vents
Air discharge vents When a certain level of impact is
detected by the impact sensor, the
emergency shut off system blocks the
high voltage current and stops the fuel
pump to minimize the risk of electrocu-
tion and fuel leakage. If the emergency
shut off system activates, your vehicle
will not restart. To restart the hybrid
system, contact your Lexus dealer.
A message is automatically displayed
when a malfunction occurs in the
hybrid system or an improper opera-
tion is attempted.
If a warning message is shown on the
multi-information display, read the
message and follow the instructions.NOTICE■
Hybrid battery (traction battery) air
intake and discharge vents●
Do not place objects that will block the
air intake vents. The hybrid battery
(traction battery) may have a reduc-
tion in hybrid battery (traction battery)
output as well as be damaged.
●
Clean the air intake and discharge
vents regularly to prevent the hybrid
battery (traction battery) from over-
heating.
●
Do not get water or foreign materials
in either the air intake and discharge
vents as this may cause a short circuit
and damage the hybrid battery (trac-
tion battery).
●
Do not carry large amounts of water
such as water cooler bottles in the
vehicle. If water spills onto the hybrid
battery (traction battery), the battery
may be damaged.
Have the vehicle inspected by your
Lexus dealer. A
B ●
A filter is installed to the air intake vent.
When the filter re mains noticeably
dirty even after cleaning the air intake
vent, filter cleaning or replacement is
recommended. When cleaning or
replacing the filter, contact your Lexus
dealer.
When “Maintenance Required for
Traction battery cooling parts at your
dealer” is shown on the multi-informa-
tion display, the filter may be clogged.
Have the filter cleaned or replaced at
your Lexus dealer.
Emergency shut off system
Hybrid warning message

2494-5. Using the driving support systems
LEXUS NX300h Owners Manu-
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Driving
1 Normal mode
For normal driving.Press the switch to change the driving
mode to normal mode when selected to
Eco mode or sport mode.
2 Eco modeIn contrast to normal mode when stepping
on the accelerator pedal, torque genera-
tion becomes slower, air conditioning
operations (heating/cooling) are
restrained, and driving is suited for
improved fuel consumption.
When not in Eco mode and the driving
mode select switch is turned to the left,
“Eco” indicator will be shown on the multi-
information display.
3 Sport mode Assists acceleration response by con-
trolling the hybrid system and steering.
Suitable for when precise handling is desir-
able, for example when driving on moun-
tain roads.
When not in sport mode and the driving
mode select switch is turned to the right,
“Sport” indicator will be shown on the
multi-information display and the hybrid
system indicator changes to the tachome-
ter. ( → P.79)■
Operation of the air conditioning sys-
tem in Eco mode
Eco mode controls the heating/cooling
operations and fan speed of the air condi-
tioning system to enhance fuel efficiency. To
improve air conditio ning performance,
adjust the fan speed or turn off Eco mode. ■
Canceling driving modes ●
Select another driv e mode. Also, sport
mode will be canceled automatically
when the power switch is turned off. ●
Normal mode and Eco mode will not be
canceled automatically until another
drive mode is selected, even if the power
switch is turned off.Driving mode select switch The driving modes can be selected
to suit driving conditions.
Selecting a driving mode

270 5-2. Using the air conditio ning system and defogger
LEXUS NX300h Owners Manu-
al_USA_OM78212U mode automatically.
This may also reduce fuel consumption.●
Recirculated air mode is selected as a
default mode when the power switch is
turned to ON mode.●
It is possible to switch to outside air mode
at any time by pressing the outside/recir-
culated air mode switch.■
Fogging up of the windows●
The windows will easily fog up when the
humidity in the vehicle is high. Pressing
“A/C” button or selecting “A/C” will
dehumidify the air from the outlets and
defog the windshield effectively.●
If you turn “A/C” off, the windows may
fog up more easily.●
The windows may fog up if the recircu-
lated air mode is used.■
Outside/recirculated air mode●
When driving on dusty roads such as tun-
nels or in heavy traffic, set the outside/
recirculated air mode switch to the recir-
culated air mode. This is effective in pre-
venting outside air from entering the
vehicle interior. During cooling opera-
tion, setting the recirculated air mode will
also cool the vehicle interior effectively.●
Outside/recirculated air mode may auto-
matically switch de pending on the tem-
perature setting or the inside
temperature.■
Registering air condit ioning settings to
electronic keys (vehicles with driving
position memory)●
Unlocking the vehicle using an electronic
key and turning the power switch to ON
mode will recall that key’s registered air
conditioning settings.
●
When the power switch is turned off, the
current air conditioning settings will auto-
matically be registered to the electronic
key that was used to unlock the vehicle.
●
The system may not operate correctly if
more than one electr onic key is in the
vicinity or if the smart access system with
push-button start is used to unlock a pas-
senger door.
●
The doors that can recall the air condi- tioning setting when unlocked using the
smart access system with push-button
start can be changed. *
For details, con-
tact your Lexus dealer. *
: The doors that can recall the driving posi-
tion memory are changed at the same
time. ■
Operation of the air conditioning sys-
tem in Eco mode ●
In the Eco mode, the air conditioning sys-
tem is controlled as follows to prioritize
fuel efficiency
• Engine speed and compressor operation
controlled to restrict heating/cooling
capacity
• Fan speed restricted when automatic
mode is selected ●
To improve air conditioning performance,
perform the following operations
• Adjust the fan speed
• Adjust the temperature setting
• Turn off Eco mode ●
Even when the drive mode is set to Eco
mode, the air conditioning eco mode can
be turned off by pressing the ■
When the outside temperature is low
The dehumidification function may not
operate even when “A/C” is pressed or “A/
C” is selected. ■
Ventilation and air conditioning odors ●
To let fresh air in, set the air conditioning
system to the outside air mode. ●
During use, various odors from inside and
outside the vehicle may enter into and
accumulate in the air conditioning sys-
tem. This may then cause odor to be
emitted from the vents.
●
To reduce potential odors from occur-
ring:
• It is recommended that the air condition-
ing system be set to outside air mode
prior to turning the vehicle off.
• The start timing of the blower may be
delayed for a short pe riod of time imme-
diately after the air conditioning system is
started in automatic mode.

272 5-2. Using the air conditio ning system and defogger
LEXUS NX300h Owners Manu-
al_USA_OM78212U Adjust the right-hand side tem-
perature setting
Function on/off indicatorsWhen the function is on, the indicator illu-
minates on the control screen.
Sub function menuWhen the button on the Remote
Touch is pressed, the following functions
can be switched on and off.
“AUTO”: Set automatic mode on/off
( → P.273)
“OFF”: Turn the fan off
“A/C”: Set cooling and dehumidification
function
“DUAL”: Adjust the temperature for driver
and passenger seats separately (“DUAL”
mode) ( → P.274)
: Set eco air conditioning mode■
Option control screen
Select on the sub menu to display
the option control screen. The functions can be switched on and off.
When the function is on, the indicator illu-
minates on the screen.
Adjusting the temperature for
driver and passenger seats sepa-
rately (“DUAL” mode) ( → P.274)
Set eco air conditioning mode Air conditioning and heater output is lim-
ited to prioritize fuel economy.
Cooling and dehumidification func-
tion
Select S-FLOW mode ( → P.273)
Prevent ice from building up on the
windshield and wiper blades
(Windshield wiper de-icer) (if
equipped)
Removing pollen from the air
(Micro dust and pollen filter) ■
Side display (Vehicles with naviga-
tion system)
Adjust the left-hand side tempera-
ture setting
Adjust the fan speed setting
Adjust the right-hand side tem-
perature setting
Set cooling and dehumidification
function on/off
Adjust the temperature for the
driver’s and front passenger’s seats
separately (“DUAL” mode)
( → P.274)
Select the air flow mode ■
Fogging up of the windows
●
The windows will easily fog up when the
humidity in the vehicle is high. Pressing E
F
G
A
B C
D
E
F
A
B
C
D
E
F

3256-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manu-
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Maintenance and care 1 Pull the hood lock release lever. The hood will pop up slightly.
2 Pull up the auxiliary catch lever and
lift the hood.WARNING●
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.■
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.331)■
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. Hood
Opening the hood
WARNING
■
Pre-driving check
Check that the hood is fully closed and
locked.
If the hood is not locked properly, it may
open while the vehicle is in motion and
cause an accident, which may result in
death or serious injury.

3276-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manu-
al_USA_OM78212U 6
Maintenance and care
Fuse box ( → P.349)
Engine coolant reservoir ( → P.330)
Engine oil filler cap ( → P.329)
Power control unit coolant reservoir ( → P.331)
Brake fluid reservoir ( → P.332)
Radiator ( → P.331)
Condenser ( → P.331)
Electric cooling fans
Engine oil level dipstick ( → P.328)
Washer fluid tank ( → P.332)■
12-volt battery
→ P.333Engine compartment
Components
A
B
C
D
E
F
G
H
I
J