2019 LEXUS NX300H overheating

3967-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_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 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

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

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

451What to do if... (Troubleshooting)
LEXUS NX300h Owners Manu-
al_USA_M78287_en451Alphabetical Index
Front side marker lights Light switch .....................................................182
Replacing light bulbs................................356
Wattage..........................................................409
Front turn signal lights Replacing light bulbs................... 355, 356
Turn signal lever ........................................... 176
Wattage..........................................................409
Fuel Capacity .........................................................403
Fuel gauge ....................................................... 79
Gas station information..........................460
Information ..................................................... 410
Refueling ......................................................... 195
Type..................................................................403
Warning light ................................................. 371
Fuel filler door .................................................195 Refueling ......................................................... 195
When the fuel filler door cannot be opened ........................................................389
Fuses ...................................................................351
G
Garage door opener ................................. 296
Gas station information ............................ 460
Gauges ................................................................79
Glove box .......................................................280
Glove box light .............................................280
Grocery bag hooks .................................... 283
H
Head restraints ...............................................135
Head-up display.............................................. 89
Headlights ........................................................182 Automatic headlight leveling ................ 183
Automatic High Beam ............................. 185
Light switch .................................................... 182
Replacing light bulbs ............................... 355
Heated steering wheel ...............................274
Heaters Automatic air conditioning system ...266
Heated steering wheel ............................ 273
Outside rear view mirrors..................... 267
Seat heaters .................................................. 274
High mounted stoplight Replacing light bulb ................................. 355
Hill-start assist control ............................... 250
Hood ................................................................. 326 Open................................................................326
Hooks Cargo hooks................................................282
Retaining hooks (floor mat) ..................... 24
Horn ................................................................... 138
Hybrid battery (traction battery) Location ............................................................. 64
Specification ................................................ 404
Hybrid battery air vent ................................. 66
Hybrid system .................................................... 61 Emergency shut off system...................... 67
Energy monitor/consumption screen93
EV drive mode............................................... 171
High voltage components ....................... 64
Hybrid System Indicator ........................... 82
Hybrid system precautions...................... 64
Hybrid vehicle driving tips ....................254
If the hybrid system will not start ........387
Overheating ................................................ 396
Power switch................................................. 168
Regenerative braking ................................. 62
Starting the hybrid system ...................... 168
Vehicle proximity noti fication system. 63

454Alphabetical Index
LEXUS NX300h Owners Manu-
al_USA_M78287_en
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