engine coolant LEXUS NX300 2020 User Guide

3396-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
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Maintenance and care
■Intercooler coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
■Coolant selection
Only use “Toyota Super Long Life Coolant”
or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite,
and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mix-
ture of 50% coolant and 50% deionized
water.
(Minimum temperature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water.
(Minimum temperature: -44°F [-42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radiator, hoses, engine
coolant reservoir cap, drain cock and water
pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
Check the radiator and condenser and
clear away any foreign objects.
If either of the above parts is extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
A
B
C
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir and the intercooler coolant reservoir
cap.
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct mixture
of water and antifreeze must be used to
provide proper lubrication, corrosion
protection and cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser
WARNING
■When the engine is hot
Do not touch the radiator or condenser
as they may be hot and cause serious
injuries, such as burns.

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

3737-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
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When trouble arises
Fluid leaks under the vehicle
(Water dripping from the air condi-
tioning after use is normal.)
 Flat-looking tires or uneven tire
wear
 Engine coolant temperature gauge
needle continually points higher
than normal
 Changes in exhaust sound
 Excessive tire squeal when corner-
ing
 Strange noises related to the sus-
pension system
 Pinging or other noises related to
the engine
 Engine misfire or misses, stumbling
or running roughly
 Appreciable loss of power
 Vehicle pulls heavily to one side
when braking 
Vehicle pulls heavily to one side
when driving on a level road
 Loss of brake effectiveness, spongy
feeling, pedal almost touches the
floor
If you think something is
wrong
If you notice any of the following
symptoms, your vehicle probably
needs adjustment or repair. Con-
tact your Lexus dealer as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms

3767-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
■High coolant temperature warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■Brake system warning light
■Malfunction indicator lamp
■SRS warning light
Warning lightDetails/Actions
Indicates that the engine is overheating
Immediately stop the vehicle in a safe place. Continu-
ing to drive the vehicle may be dangerous.
Handling method ( P.403)
Warning lightDetails/Actions
(Yellow)
Indicates a malfunction in the electric parking brake
 Have the vehicle inspected by your Lexus dealer
immediately.
Warning lightDetails/Actions
(U.S.A.)
(Canada)
Indicates a malfunction in:
 The electronic engine control system;
 The electronic throttle control system; or
 The electronic automatic transmission control system
 Have the vehicle inspected by your Lexus dealer
immediately.
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.

3867-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
speed range
■If “Radar Cruise Control Unavailable
See Owner’s Manual” is shown
The dynamic radar cruise control with full-
speed range system is suspended tempo-
rarily or until the problem shown in the mes-
sage is resolved. (causes and coping
methods: P.197)
■If “Radar Cruise Control Unavailable” is
shown
The dynamic radar cruise control with full-
speed range system cannot be used tempo-
rarily. Use the system when it becomes
available again.
■If “Oil Maintenance Required Soon” is
shown
Indicates that the engine oil is scheduled to
be changed. (The indicator will not work
properly unless the oil maintenance data
has been reset.)
Check the engine oil, and change if neces-
sary. After changing the engine oil, the oil
change system shou ld be reset. (P.337)
■If “Oil Maintenance Required” is shown
Indicates that the engine oil should be
changed. (After the engine oil is changed
and the oil maintenance data has been
reset.)
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the
engine oil, the oil change system should be
reset. ( P.337)
■If “See Owner’s Manual” is shown
●If the following messages are shown, fol-
lowing the instructions, accordingly.
• “Engine Coolant Temp High” ( P.403)
●If the following messages are shown,
there may be a malfunction.
Immediately have the vehicle inspected
by your Lexus dealer.
• “Braking Power Low”
• “Smart Access System Malfunction”
●If the following messages are shown,
there may be a malfunction.
Immediately stop the vehicle in a safe
place and contact your Lexus dealer.
Continuing to drive the vehicle may be
dangerous.
• “Oil Pressure Low” • “Charging System Malfunction”
• “Transmission Fluid Temp High”
■Warning buzzer
 P.382
NOTICE
■“High Power Consumption Partial
Limit On AC/Heater Operation” is
frequently shown
There is a possible malfunction relating
to the charging system or the battery
may be deteriorating. Have the vehicle
inspected by your Lexus dealer.

4037-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
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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
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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
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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.

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