2020 LEXUS NX300h overheating

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

LEXUS NX300h Owners Manual_USA_M78530_en
Alphabetical Index471
Power window lock switch.....................149
Power window precautions ...................149
Rear door child-protectors ..................... 113
Removed key battery precautions ...369
Seat belt extender precautions ............. 28
Seat belt precautions ...................................47
Seat heater precautions ......................... 297
Child-protectors............................................. 113
Cleaning.............................................. 330, 333 Aluminum wheels ......................................330
Exterior ...........................................................330
Interior ............................................................. 333
Seat belts........................................................ 333
Clock ................................................................. 310
Compass ......................................................... 326
Condenser ..................................................... 350
Console box .................................................. 304
Consumption screen .................................... 99
Coolant Capacity ......................................................... 425
Checking ....................................................... 349
Preparing and checking before winter..........................................................................277
Warning light ............................................... 387
Cooling system............................................. 349 Hybrid system overheating ....................416
Cornering lights .............................................. 191 Coussins gonflables
Modification et élimin ation en fin de vie
des coussins gonflables ...................... 462
Précautions avec les coussins gonflables latéraux ....................................................... 458
Précautions avec les coussins gonflables latéraux et rideau ................................... 458
Précautions avec les coussins gonflables pour votre enfant ................................... 458
Précautions avec les coussins gonflables rideau........................................................... 458
Précautions générales avec les coussins gonflables .................................................. 458
Cruise control Dynamic radar cruise control with full-
speed range ..............................................236
Cup holders ................................................... 304
Curtain shield airbags .................................. 32
Customizable features ................................441
D
Daytime running light system .................. 190
Deck board .................................................... 307
Deck under tray ........................................... 307
Defogger Outside rear view mirrors.................... 290
Rear window ............................................... 290
Windshield ................................................... 290
Differential .......................................................427
Dimension ...................................................... 422
Dinghy towing................................................. 173

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

LEXUS NX300h Owners Manual_USA_M78530_en
Alphabetical Index475
Hybrid battery (traction battery)Location............................................................. 70
Specification ................................................. 424
Hybrid battery air vent ..................................72
Hybrid system ...................................................67 Emergency shut off system ......................73
Energy monitor/consumption screen99
EV drive mode ............................................. 177
High voltage components ....................... 70
Hybrid System Indicator ........................... 87
Hybrid system precautions ..................... 70
Hybrid vehicle driving tips .................... 275
If the hybrid system will not start ........ 407
Overheating...................................................416
Power switch ................................................. 174
Regenerative braking ................................. 68
Starting the hybrid system....................... 174
Vehicle proximity notification system 69
Hybrid System Indicator.............................. 87
Hybrid transmission...................................... 179
I
I/M test ............................................................ 340
Identification Engine ............................................................. 423
Vehicle ............................................................ 422
Ignition switch (Power switch) ................. 174
Illuminated entry system ...........................300
Immobilizer system .........................................75
Indicators ........................................................... 82
Initialization Items to initialize ......................................... 452
Inside rear view mirror ................................144
Instrument panel light control ................... 88
Interior lights..................................................300 Intuitive parking assist
Function .......................................................... 247
Warning message .....................................248
J
JackPositioning a floor jack ............................ 344
Vehicle-equipped jack .......................... 400
Jack handle ....................................................400
Jam protection function Moon roof ........................................................ 151
Power back door closer ........................... 121
Power windows ........................................... 148
Rear seats ........................................................137
K
Keyless entrySmart access system with push-button start ..................................................................126
Wireless remote control ......................... 107
Keys.................................................................... 106 Battery-saving function............................. 127
Electronic key ............................................... 106
Engine switch .................................................174
If the electronic key does not operate properly ........................................................ 410
If you lose your keys ................................ 409
Key number plate ....................................... 106
Keyless entry .........................................110, 126
Mechanical key ............................................ 106
Power switch..................................................174
Replacing the battery .............................. 368
Warning buzzer ........................................... 127
Wireless remote control key ................ 107
Knee airbags .................................................... 32

LEXUS NX300h Owners Manual_USA_M78530_en
Alphabetical Index477
MirrorsInside rear view mirror.............................. 144
Outside rear view mirror defoggers290
Outside rear view mirrors ......................146
Vanity mirrors............................................... 310
Moon roof Jam protection function............................. 151
Operation....................................................... 150
Warning message.......................... 152, 396
Multi-information display Clock .................................................................. 84
Drive information .......................................... 90
Dynamic radar cruise control with full-speed range .............................................. 236
Energy monitor.............................................. 99
Language....................................................... 444
LDA (Lane Departure Alert with steering control) ........................................................ 226
LTA (Lane Tracing Assist)...................... 217
Warning messages ..................................396
N
Noise from under vehicle ...............................6
O
Odometer ......................................................... 84
Oil Engine oil ....................................................... 424
Rear differential oil .................................... 427
Opener Back door..........................................................117
Fuel filler door.............................................. 202
Hood................................................................ 344 Outside rear view mirrors .........................146
Adjusting and folding................................ 146
Blind Spot Monitor (BSM)......................261
Linked mirror functi on when reversing
............................................................................147
Mirror position memory .......................... 138
Outside rear view mirror defoggers290
Outside temperature display .................... 84
Overheating ....................................................416
P
Paddle shift switches ..................................... 181
Panic mode ..................................................... 108
Parking brake Operation ....................................................... 183
Parking brake engaged warning buzzer/message ....................................................... 184
Warning light .............................................. 390
Parking lights Light switch .................................................... 189
Replacing light bulb .................................. 374
Parking Support Brake fu nction (for static
objects) ......................................................... 252 Indicator................................................... 80, 82
Warning light .............................................. 390
Warning messages.................................. 258
PCS (Pre-Collision System) Function ........................................................... 210
PCS switch...................................................... 212
Warning light .............................................. 389
Warning message .................................... 396
Personal lights...............................................300 Switch................................................................ 301
PKSA (Parking Support Alert) .............. 246