2020 LEXUS NX300 cooling

3406-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703;
FMVSS No.116 DOT 4 or SAE J1704
brake fluid
Items
Clean funnel
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
Check the battery as follows.
■Battery exterior
Make sure that the battery terminals
are not corroded and that there are no
loose connections, cracks, or loose
clamps.
Terminals
Hold-down clamp
WARNING
■When the electric cooling fans are
operating
Do not touch the engine compartment.
With the engine switch in IGNITION
ON mode, the electric cooling fans may
automatically start to run if the air condi-
tioning is on and/or the coolant tempera-
ture is high. Be sure the engine switch is
off when working near the electric cool-
ing fans or radiatorgrille.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your eyes,
flush the affected area with clean water
immediately.
If you still experience discomfort, see a
doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid leve l in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Checking the battery
A
B

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

4047-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Engine
Reservoir
“FULL” line
“LOW” line
Intercooler radiatorReservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Engine
Water can be used in an emergency if
coolant is unavailable.
Intercooler radiator
Water can be used in an emergency if
coolant is unavailable.
A
B
A
B
C
A
B
C

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.

4118-1. Specifications
LEXUS NX300 Owners Manual_USA_M78389_en
8
Vehicle specifications
*: The coolant capacity is the quantity of reference.
If replacement is necessary, contact your Lexus dealer.
■Spark plug
■Battery
■Charging rates
Cooling system
Capacity*
Gasoline
engine8.3 qt. (7.9 L, 7.0 Imp.qt.)
Intercooler3.1 qt. (2.9 L, 2.6 Imp.qt.)
Coolant type
Use either of the following:
 “Toyota Super Long Life Coolant”
 Similar high-quality ethy lene glycol-based non-
silicate, non-amine, non-nitrite, and nonborate
coolant with long-life hybrid organic acid tech-
nology
Do not use plain water alone.
Ignition system
MakeNGK DILFR7K9G
Gap0.04 in. (0.9 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system
Specific gravity reading at 68°F
(20°C):1.25 or higher
If the specific gravity is lower than the standard
value, charge the battery.
Quick charge
Slow charge15 A max.
5 A max.

LEXUS NX300 Owners Manual_USA_M78389_en
Alphabetical Index457
Consumption screen .................................... 92
Coolant
Capacity .............................................................411
Checking .......................................................338
Preparing and checking before winter......................................................................... 266
Warning light ............................................... 376
Cooling system............................................. 338 Engine overheating ..................................403
Cornering lights ............................................ 180
Coussins gonflables Modification et élimin ation en fin de vie
des coussins gonflables ......................448
Précautions avec les coussins gonflables latéraux ........................................................ 444
Précautions avec les coussins gonflables latéraux et rideau.................................... 444
Précautions avec les coussins gonflables pour votre enfant.................................... 444
Précautions avec les coussins gonflables rideau ........................................................... 444
Précautions générales avec les coussins gonflables ................................................... 444
Cruise control Dynamic radar cruise control with full-speed range .............................................. 225
Cup holders ................................................... 293
Curtain shield airbags .................................. 32
Customizable features ...............................427
D
Daytime running light system ................... 179
Deck board .................................................... 296
Deck under tray ........................................... 296 Defogger
Outside rear view mirrors.................... 280
Rear window ............................................... 280
Windshield ................................................... 280
Differential ........................................................ 412
Dimension ......................................................408
Dinghy towing.................................................164
Display BSM (Blind Spot Monitor)................... 250
Drive information ..........................................83
Dynamic radar cruise control with full-
speed range .............................................. 225
Head-up display........................................... 88
Intuitive parking assist ..............................236
LDA (Lane Departure Alert with steering control) ......................................................... 215
LTA (Lane Tracing Assist) ................... 206
Multi-information display .......................... 82
Warning messages.................................. 384
Do-it-yourself maintenance ......................331
Door lock Back door ....................................................... 105
Side doors ...................................................... 100
Smart access system with push-button start ................................................................... 116
Wireless remote control ........................... 97
Doors Automatic door lock ing and unlocking
system............................................................ 103
Back door ....................................................... 104
Door glasses ................................................. 138
Door lock ........................................................100
Outside rear view mirrors...................... 136
Rear door child-protectors ................... 103
Side doors ...................................................... 100