2019 LEXUS NX300H cooling

3977-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
7
When trouble arises
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.
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 (radiato r) 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.
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-
al_USA_M78287_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.

448Alphabetical Index
LEXUS NX300h Owners Manu-
al_USA_M78287_en
Brake Brake Hold ..................................................... 179
Fluid .................................................................. 407
Parking brake ................................................ 177
Regenerative braking ................................. 62
Warning light ...............................................368
Brake assist .................................................... 249
Brake Hold ....................................................... 179
Break-in tips...................................................... 151
Brightness control Instrument panel light control ................ 83
BSM (Blind Spot Monitor)......................... 241 Blind Spot Monitor function................. 243
Rear Cross Traffic Alert function....... 245
BSM (Blind Spot Monitor) main switch241
C
Card key .......................................................... 100
Care Aluminum wheels ........................................ 312
Exterior .............................................................315
Interior ...............................................................315
Seat belts..........................................................315
Cargo capacity.........................155, 158, 402
Cargo hooks ................................................. 282
Cargo net hooks .......................................... 282
Chains .............................................................. 257
Child restraint system....................................47 Booster seats installation .......................... 53
Convertible seats installation.................. 52
Front passenger occupant classification system ............................................................... 41
Infant seats installation .................................. 51
Installing CRS with LATCH anchors . 55
Installing CRS with seat belts.................... 51
Installing CRS with top tether strap..... 57
LATCH anchors ........................................... 55 Child safety ....................................................... 46
12-volt battery precautions ...... 335, 395
Airbag precautions ...................................... 37
Back door precautions ............................ 108
Child restraint system ................................. 47
How your child should wear the seat belt............................................................................. 28
Installing child restraints............................. 47
Moon roof precautions............................ 146
Power window lock switch .....................143
Power window precautions ...................143
Rear door child-protectors ................... 107
Removed key battery precautions... 350
Seat belt extender precautions.............. 28
Seat belt precautions .................................. 46
Seat heater precautions.......................... 273
Child-protectors............................................107
Cleaning ..................................................312, 315 Aluminum wheels ........................................312
Exterior..............................................................312
Interior .............................................................. 315
Seat belts ......................................................... 315
Clock ................................................................ 286
Compass .......................................................... 301
Condenser ..................................................... 332
Console box ..................................................280
Consumption screen .................................... 93
Coolant Capacity ........................................................ 405
Checking ........................................................ 331
Preparing and checking before winter..........................................................................256
Warning light .............................................. 368
Cooling system...............................................331 Hybrid system overheating ................. 396
Cornering lights ............................................ 184
Cruise control Dynamic radar cruise control with full-
speed range ................................................ 217
Cup holders ...................................................280
Curtain shield airbags .................................. 32
Customizable features ................................ 421