2020 LEXUS NX300h engine coolant

4167-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
■“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
WARNING
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.
■When exchanging the 12-volt battery
After exchanging, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the exchanged 12-
volt battery. If not properly installed,
gases (hydrogen) may leak into the vehi-
cle interior, and there is the possible dan-
ger of the gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.84)
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

4177-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
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 coolant is unavailable.
6
Start the hybrid system 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.)
7 If the fans are not operating:
Stop the hybrid system 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 hybrid system and contact
your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Lexus dealer.
A
B
A
B
C

4187-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
■If “Hybrid System Overheated” is
shown on the multi-information dis-
play
1 Stop the vehicle in a safe place.
2 Stop the hybrid system and care-
fully lift the hood.
3 After the hybrid system has cooled
down, inspect the hoses and radia-
tor 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.
Reservoir “FULL” line
“LOW” line 5
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
6After 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.
A
B
A
B
C
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.

4197-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
1 Stop the hybrid system. Shift the
shift lever to P and set the parking
brake.
2 Remove the mud, snow or sand
from around the front wheels.
3 Place wood, stones or some other
material under the front wheels to
help provide traction.
4 Restart the hybrid system.
5 Shift the shift lever to D or R,
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press to turn off TRAC. ( P.271)
WARNING
●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 damage 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.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure

4258-1. Specifications
LEXUS NX300h Owners Manual_USA_M78530_en
8
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.

4368-1. Specifications
LEXUS NX300h Owners Manual_USA_M78530_ennation, can cause heat buildup and
possible tire failure.
Glossary of tire terminology
Tire related
termMeaning
Cold tire
inflation
pressure
Tire pressure when the vehi-
cle 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
pressureThe maximum cold inflated
pressure to which a tire may
be inflated, shown on the
sidewall of the tire
Recom-
mended
inflation
pressureCold tire inflation pressure
recommended by a manu-
facturer
Accessory
weight
The combined weight (in
excess of those 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 equipment
(whether installed or not)
Curb weight
The weight of a motor vehi-
cle with standard equip-
ment, 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
occupant
weight150 lb. (68 kg) times the
number of occupants speci-
fied in the second column of
Table 1
* that follows
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 regular production
options weighing over 5 lb.
(2.3 kg) in excess of the
standard items which they
replace, not previously con-
sidered in curb weight or
accessory weight, including
heavy duty brakes, ride lev-
elers, roof rack, heavy duty
12-volt battery, and special
trim
Rim
A metal support for a tire or
a tire and tube assembly
upon which the tire beads
are seated
Rim diame-
ter
(Wheel
diameter)
Nominal diameter of the
bead seat
Rim size des-
ignationRim diameter and width
Tire related termMeaning

LEXUS NX300h Owners Manual_USA_M78530_en
Alphabetical Index473
Emergency flashers .................................... 378
Emergency, in case ofIf a warning buzzer sounds ..................386
If a warning light turns on ......................386
If a warning message is displayed.....396
If the 12-volt battery is discharged ...... 412
If the electronic key does not operate properly........................................................ 410
If the fuel filler door cannot be opened .........................................................................409
If the hybrid system will not start ........ 407
If the vehicle is trapped in rising water ......................................................................... 379
If you have a flat tire ................................. 400
If you lose your keys.................................409
If you think something is wrong .........384
If your vehicle becomes stuck...............419
If your vehicle has to be stopped in an
emergency ................................................ 378
If your vehicle needs to be towed ...... 381
If your vehicle overheats ..........................416
Energy monitor ............................................... 99
Engine Accessory mode ......................................... 176
Compartment ............................................. 346
Engine switch................................................. 174
Hood................................................................ 344
How to start the hybrid system ............ 174
Identification number ............................... 423
If your vehicle has to be stopped in an
emergency ................................................ 378
Ignition switch (power switch) .............. 174
Overheating...................................................416
Power switch ................................................. 174 Engine compartment cover .................... 347
Engine coolant
Capacity .........................................................425
Checking .......................................................349
Preparing and checking before winter.......................................................................... 277
Warning light ...............................................387
Engine coolant temperature gauge ....... 84
Engine oil Capacity ......................................................... 424
Checking ....................................................... 347
Warning light ...............................................387
Engine switch .................................................. 174
EPS (Electronic Power Steering) Function .......................................................... 270
Warning light .............................................. 388
EV drive mode................................................ 177
EV indicator ...................................................... 68
Event data recorder (E DR) ........................... 8
F
Flat tire .............................................................400
Tire pressure warning system .............357
Floor mats .......................................................... 24
Fluid Brake ................................................................ 427
Transmission................................................. 426
Washer ............................................................ 351
Fog lights Replacing light bulbs ................................ 374
Switch................................................................ 195
Front passenger occupant classification system ................................................................ 41

482Alphabetical Index
LEXUS NX300h Owners Manual_USA_M78530_en
W
Warning buzzers Approach warning.................................... 242
Downshifting ..................................................182
Intuitive parking assist................................251
Light reminder.............................................. 190
Open door......................................................... 111
Seat belt reminder.......................................391
Vehicle sway warning ................... 221, 230
Warning lights ABS ................................................................. 388
Brake hold operated indicator ...........390
Brake Override System ......................... 393
Brake system ...............................................386
Charging system .......................................386
Drive-Start Control .................................. 393
Electric power steering ......................... 388
High coolant temperature .................... 387
LDA indicator..............................................389
Low engine oil pressure......................... 387
Low fuel level .................................................391
LTA indicator ...............................................389
Malfunction indicator lamp................... 387
Master warning light ................................ 392
Parking brake indicator ..........................390
PCS warning light .....................................389
PKSB OFF indicator ................................390
Seat belt reminder light ............................391
Slip indicator ................................................390
SRS................................................................... 388
Tire pressure ................................................ 392
Warning messages ..................................... 396 Washer
Checking ........................................................ 351
Low washer fluid warning message 351, 396
Preparing and checking before winter .......................................................................... 277
Switch....................................................195, 200
Washing and waxing.................................. 330
Weights Cargo capacity ........................ 161, 164, 422
Load limits ..................................................... 422
Weights .......................................................... 422
Wheels ............................................................. 365 Replacing wheels ...................................... 365
Size ....................................................................428
Window glasses ............................................ 148
Window lock switch .....................................149
Windows Power windows ........................................... 148
Rear window defogger.......................... 290
Washer ................................................195, 200
Windshield wiper de-icer ........................ 294
Windshield wipers Intermittent windshield wipers ............. 195
Rain-sensing windshield wipers ...........197
Winter driving tips........................................277
Wireless charger ...........................................312
Wireless remote control key ....................107 Battery-saving function............................. 127
Locking/Unlocking ................................... 107
Panic mode ....................................................108
Replacing the battery .............................. 368