2019 LEXUS NX300H coolant temperature

3336-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manu-
al_USA_M78287_en
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Maintenance and care
■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.
If none of the washer do not work or
the “Windshield Washer Fluid Low” on
the multi-information display, the
washer tank may be empty. Add
washer fluid.
WARNING
■When the electric cooling fans are
operating
Do not touch the engine compartment.
With the 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.
Be sure the power switch is off when
working near the electric cooling fans or
radiator grille.
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 and adding the washer
fluid

3657-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
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When trouble arises
4 Tighten down the towing eyelet
securely using a wheel nut wrench.
5 Securely attach cables or chains to
the towing eyelet.
Take care not to damage the vehicle body.
6Enter the vehicle being towed and
start the hybrid system.
If the hybrid system does not start, turn the
power switch to ON mode.
7Shift the shift lever to N and release
the parking brake.
When the shift lever cannot be shifted:
P.174
■While towing
If the hybrid system is off, the power assist
for the brakes and steering will not function,
marking steering and braking more difficult.
■Wheel nut wrench
Wheel nut wrench is installed in luggage
compartment. ( P.380)
 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 hybrid system
 Engine misfire or misses, stumbling
or running roughly
 Appreciable loss of power
 Vehicle pulls heavily to one side
when braking
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

3687-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
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■Low engine oil pressure warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■High coolant temperature warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■Brake system warning light
■Malfunction indicator lamp
Warning lightDetails/Actions
Indicates that the engine oil pressure is too low
Immediately stop the vehicl e in a safe place and con-
tact your Lexus dealer. Continuing to drive the vehicle
may be dangerous.
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.396)
Warning lightDetails/Actions
(Yellow)
Indicates a malfunction in:
The regenerative braking system;
 The electronically controlled brake system; or
 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 hybrid system;
 The electronic engine control system;
 The electronic throttle control system; or
 The emission control system
 Have the vehicle inspected by your Lexus dealer
immediately.

3967-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
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“Engine Coolant Temp High” is
shown on the multi-information dis-
play
1 Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
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 hybrid system has cooled
down sufficiently, inspect the hoses and radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4
The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emergency if
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
hybrid system power is experi-
enced. (For example, the vehicle
speed does not increase.)
 “Engine Coolant Temp High” or
“Hybrid System Overheated” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures
A
B
A
B
C

3987-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_enWater can be used in an emergency if
coolant is unavailable.
6
After stopping the hybrid system
and waiting for 5 minutes or more,
start the hybrid system again and
check if “Hybrid System Over-
heated” is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the hybrid system and contact your
Lexus dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be driven
normally.
However, if the message appears again fre-
quently, contact your 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.
●After the hybrid system has been
turned off, check that the “READY”
indicator is off. When the hybrid sys-
tem is operating, the gasoline engine
may automatically start, or the cooling
fan may suddenly operate even if the
gasoline engine stops. Do not touch or
approach rotating parts such as the
fan, which may lead to fingers or cloth-
ing (especially a tie, a scarf or a muf-
fler) getting caught, resulting in serious
injury.
●Do not loosen the coolant reservoir
cap while the hybrid system and radia-
tor are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine/power control
unit coolant
Add coolant slowly after the hybrid sys-
tem has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too
quickly can cause dama ge to the hybrid
system.
■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.

4058-1. Specifications
LEXUS NX300h Owners Manu-
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Vehicle specifications
as an example):
• The 0W in 0W-20 indicates the characteristic of the oil which allows
cold startability. Oils with a lower
value before the W allow for easier
starting of the engine in cold
weather.
• The 20 in 0W-20 indicates the vis- cosity characteristic of the oil when
the oil is at high temperature. An oil
with a higher viscosity (one with a
higher value) may be better suited if
the vehicle is operated at high
speeds, or under extreme load con-
ditions. How to read oil container label:
The International Lubricant Specifica-
tion Advisory Committee (ILSAC)
Certification Mark is added to some oil
containers to help you select the oil you
should use.
*: The coolant capacity is the quantity of reference.
If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
Gasoline
engine
Vehicles with towing package
7.7 qt. (7.3 L, 6.4 Imp.qt.)
Vehicles without towing package
7.1 qt. (6.7 L, 5.9 Imp.qt.)
Power con-
trol unit3.3 qt. (3.1 L, 2.7 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 hy brid organic acid tech-
nology
Do not use plain water alone.

450Alphabetical Index
LEXUS NX300h Owners Manu-
al_USA_M78287_en
Emergency, in case of If a warning buzzer sounds .................. 367
If a warning light turns on ...................... 367
If a warning message is displayed..... 376
If the 12-volt battery is discharged .... 392
If the electronic key does not operate properly.......................................................389
If the fuel filler door cannot be opened .........................................................................389
If the hybrid system will not start ........ 387
If you have a flat tire .................................. 379
If you lose your keys................................ 388
If you think something is wrong .........365
If your vehicle becomes stuck.............399
If your vehicle has to be stopped in an
emergency ................................................360
If your vehicle needs to be towed ..... 362
If your vehicle overheats ........................396
Energy monitor ............................................... 93
Engine Accessory mode .........................................170
Compartment ............................................. 328
Engine switch................................................ 168
Hood................................................................ 326
How to start the hybrid system ........... 168
Identification number ...............................403
If your vehicle has to be stopped in an
emergency ................................................360
Ignition switch (power switch) ............. 168
Overheating.................................................396
Power switch ................................................ 168
Engine compartment cover .................... 329
Engine coolant Capacity .........................................................405
Checking .........................................................331
Preparing and checking before winter......................................................................... 256
Warning light ...............................................368
Engine coolant temperature gauge ........79 Engine oil
Capacity ........................................................ 404
Checking .......................................................329
Warning light .............................................. 368
Engine switch ................................................. 168
EPS (Electronic Power Steering) Function .......................................................... 249
Warning light .............................................. 369
EV drive mode................................................. 171
EV indicator ...................................................... 62
Event data recorder (E DR) ............................7
F
Flat tire ............................................................. 379
Tire pressure warning system .............339
Floor mats .......................................................... 24
Fluid Brake ................................................................407
Transmission................................................ 406
Washer ...........................................................333
Fog lights Replacing light bulbs ............................... 355
Switch................................................................188
Front passenger occupant classification system ................................................................ 41
Front passenger’s seat belt reminder light ............................................................................ 371
Front seat heaters.........................................274
Front seats ........................................................126 Adjustment ......................................................126
Cleaning .......................................................... 315
Correct driving posture ............................ 25
Driving position memory .........................132
Head restraints............................................. 135
Power easy access system .....................132
Seat heaters .................................................. 274
Seat position memory ...............................132

454Alphabetical Index
LEXUS NX300h Owners Manu-
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O
Odometer ..........................................................79
Oil Engine oil .......................................................404
Rear differential oil .................................... 407
Opener Back door........................................................... 111
Fuel filler door............................................... 195
Hood................................................................ 326
Outside rear view mirrors ........................ 140 Adjusting and folding ............................... 140
Blind Spot Monitor (BSM) ..................... 241
Linked mirror functi on when reversing
.......................................................................... 140
Mirror position memory........................... 132
Outside rear view mirror defoggers 267
Outside temperature display .....................79
Overheating .................................................. 396
P
Paddle shift switches .................................... 175
Panic mode ......................................................102
Parking brake Operation........................................................ 177
Parking brake engaged warning buzzer/message ........................................................178
Warning light ................................................. 371
Parking lights Light switch .....................................................182
Replacing light bulb..................................355
Parking Support Brake function (for static objects) ......................................................... 232Indicator ....................................................75, 76
Warning light ............................................... 370
Warning messages .................................. 238 PCS (Pre-Collision System)
Function ..........................................................202
PCS switch....................................................204
Warning light .............................................. 369
Warning message ..................................... 376
Personal lights................................................276 Switch............................................................... 277
PKSA (Parking Support Alert) .............. 226
Power back door opener and closer .......111
Power control unit coolant Capacity ........................................................ 405
Checking ........................................................ 331
Preparing and checking before winter..........................................................................256
Radiator .......................................................... 332
Power easy access system ........................132
Power outlets ................................................ 287
Power steering (Electric Power Steering system) .......................................................... 249Warning light .............................................. 369
Power switch .................................................. 168
Power windows Door lock linked window operation ..143
Jam protection function ............................142
Operation ........................................................142
Window lock switch...................................143
Pre-Collision System (PCS) Function ..........................................................202
PCS switch....................................................204
Warning light .............................................. 369
Warning message ..................................... 376