2018 LEXUS NX300h overheating

394 7-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U 
“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

448 Alphabetical Index
LEXUS NX300h Owners Manu-
al_USA_OM78212U Brake
Brake Hold .................................................... 180
Fluid ..................................................................405
Parking brake ................................................ 177
Regenerative braking ................................. 62
Warning light ...............................................366
Brake assist .................................................... 250
Brake Hold ...................................................... 180
Break-in tips...................................................... 151
Brightness control
Instrument panel light control ................ 84
BSM (Blind Spot Monitor)......................... 241
Blind Spot Monitor function................. 243
Rear Cross Traffic Alert function....... 246
BSM (Blind Spot Monitor) main switch241
C
Card key ...........................................................102
Care
Aluminum wheels ........................................314
Exterior ............................................................. 314
Interior ............................................................... 314
Seat belts.......................................................... 317
Cargo capacity...................................155, 400
Cargo hooks ................................................. 284
Cargo net hooks .......................................... 284
Chains .............................................................. 258
Child restraint system....................................47
Booster seats installation .......................... 53
Convertible seats installation.................. 52
Front passenger occupa nt classification
system ............................................................... 41
Infant seats definition................................... 49
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 .......334, 393
Airbag precautions.......................................37
Back door precautions.............................. 110 Child restraint system ................................. 47
How your child should wear the seat belt
............................................................................. 28
Installing child restraints............................. 47
Moon roof precautions............................ 148
Power window lock switch .................... 145
Power window precautions .................. 145
Rear door child-protectors ................... 109
Removed key battery precautions... 348
Seat belt extender precautions.............. 28
Seat belt precautions .................................. 46
Seat heater precautions.......................... 275
Child-protectors........................................... 109
Cleaning .................................................. 314, 317
Aluminum wheels ........................................314
Exterior..............................................................314
Interior ...............................................................317
Seat belts ..........................................................317
Clock ................................................................288
Compass ......................................................... 303
Condenser .......................................................331
Console box .................................................. 282
Consumption screen .................................... 94
Coolant
Capacity ........................................................ 403
Checking ...................................................... 330
Preparing and checking before winter
.......................................................................... 257
Warning light .............................................. 366
Cooling system............................................. 330
Hybrid system overheating ..................394
Cruise control
Dynamic radar cruise control with full-
speed range ............................................... 217
Cup holders ................................................... 282
Curtain shield airbags .................................. 32
Customizable features ................................419
D
Daytime running light system .................. 184
Deck board .................................................... 285
Deck under tray ........................................... 285

450 Alphabetical Index
LEXUS NX300h Owners Manu-
al_USA_OM78212U Accessory mode .........................................170
Compartment ............................................. 327
Engine switch................................................ 168
Hood................................................................ 325
How to start the hybrid system ........... 168
Identification number ................................ 401
If your vehicle has to be stopped in an
emergency ............................................... 358
Ignition switch (power switch) ............. 168
Overheating................................................. 394
Power switch ................................................ 168
Engine compartment cover .................... 328
Engine coolant
Capacity .........................................................403
Checking .......................................................330
Preparing and checking before winter
......................................................................... 257
Warning light ...............................................366
Engine coolant temperature gauge ........79
Engine oil
Capacity ......................................................... 402
Checking ....................................................... 328
Warning light ...............................................366
Engine oil maintenance data .................. 329
Engine switch ................................................. 168
EPS (Electronic Power Steering)
Function ..........................................................250
Warning light ............................................... 367
EV drive mode................................................. 171
EV indicator ...................................................... 62
Event data recorder (EDR) ............................7 F
Flat tire ..............................................................377
Tire pressure warning system ............ 338
Floor mats .......................................................... 24
Fluid
Brake ............................................................... 405
Transmission................................................ 404
Washer ........................................................... 332
Fog lights
Replacing light bulbs ................................353
Switch................................................................ 189
Front passenger occupant classification
system ................................................................ 41
Front passenger’s seat belt reminder light
.......................................................................... 369
Front seats ........................................................128
Adjustment ..................................................... 128
Cleaning ...........................................................317
Correct driving posture ............................ 25
Driving position memory .........................134
Head restraints..............................................137
Power easy access system .....................134
Seat heaters .................................................. 276
Seat position memory ...............................134
Front side marker lights
Light switch .................................................... 183
Replacing light bulbs ................................354
Wattage ..........................................................407
Front turn signal lights
Replacing light bulbs ................... 353, 354
Turn signal lever ...........................................176
Wattage ..........................................................407
Fuel
Capacity .......................................................... 401
Fuel gauge ........................................................ 79
Gas station information ......................... 460
Information ................................................... 408
Refueling.......................................................... 196
Type ................................................................... 401
Warning light .............................................. 369
Fuel filler door .................................................196

451What to do if... (Troubleshooting)
LEXUS NX300h Owners Manu-
al_USA_OM78212U Alphabetical Index
451Refueling ..........................................................196
When the fuel filler door cannot be
opened ........................................................ 387
Fuses ................................................................. 349 G
Garage door opener ................................. 298
Gas station information ............................ 460
Gauges ................................................................79
Glove box ....................................................... 282
Glove box light ............................................. 282
Grocery bag hooks .................................... 285 H
Head restraints ............................................... 137
Head-up display.............................................. 90
Headlights ....................................................... 183
Automatic headlight leveling ................ 184
Automatic High Beam ............................. 186
Light switch .................................................... 183
Replacing light bulbs................................ 353
Heated steering wheel ...............................276
Heaters
Automatic air conditioning system ...268
Heated steering wheel............................ 275
Outside rear view mirrors .................... 269
Seat heaters .................................................. 275
High mounted stoplight
Replacing light bulb..................................353
Hill-start assist control ............................... 250
Hood ................................................................. 325
Warning message........................... 107, 374
Hooks
Cargo hooks................................................ 284
Retaining hooks (floor mat)......................24
Horn ................................................................... 140
Hybrid battery (traction battery)
Location............................................................. 64
Specification ................................................. 402
Hybrid battery air vent ................................. 66
Hybrid system .................................................... 61 Emergency shut off system...................... 67
Energy monitor/consumption screen 94
EV drive mode............................................... 171
High voltage components ....................... 64
Hybrid System Indicator ........................... 82
Hybrid system precautions...................... 64
Hybrid vehicle driving tips ....................255
If the hybrid system will not start ....... 385
Overheating .................................................394
Power switch................................................. 168
Regenerative braking ................................. 62
Starting the hybrid system ...................... 168
Vehicle proximity noti fication system. 63
Hybrid System Indicator.............................. 82
Hybrid transmission...................................... 173
I
I/M test ............................................................ 322
Identification
Engine............................................................... 401
Vehicle ........................................................... 400
Ignition switch (Power switch) ................ 168
Illuminated entry system ........................... 278
Immobilizer system........................................ 69
Indicators ............................................................74
Initialization
Engine oil maintenance data................329
Items to initialize ......................................... 429
Tire pressure warning system ...............341
Inside rear view mirror ............................... 140
Instrument panel light control ................... 84
Interior lights.................................................. 278
Intuitive parking assist
Function .......................................................... 227
Warning message ..................................... 229

453What to do if... (Troubleshooting)
LEXUS NX300h Owners Manu-
al_USA_OM78212U Alphabetical Index
453M
Maintenance
Do-it-yourself maintenance ................. 324
General maintenance ...............................319
Maintenance data..................................... 400
Maintenance requirements ....................319
Malfunction indicator lamp ..................... 366
Meter
Head-up display ........................................... 90
Indicators ...........................................................74
Instrument panel light control ................ 84
Meters ................................................................ 79
Multi-information display .......................... 85
Warning lights .............................................365
Warning messages .................................. 374
Micro dust and pollen filter ..................... 273
Microphone ................................................... 306
Mirrors
Inside rear view mirror............................. 140
Outside rear view mirror defoggers269
Outside rear view mirrors ...................... 142
Vanity mirrors..............................................288
Moon roof
Jam protection function............................ 147
Operation........................................................146
Warning message...........................148, 374
Multi-information display
Drive information .......................................... 86
Dynamic radar cruise control with full-
speed range ................................................ 217
Energy monitor.............................................. 94
Language....................................................... 422
LDA (Lane Departure Alert with steering
control) ..........................................................210
Warning messages .................................. 374
N
Noise from under vehicle ...............................6 O
Odometer ..........................................................79
Oil
Engine oil........................................................402
Rear differential oil......... .......... ........... ...... 405
Opener
Back door ......................................................... 113
Fuel filler door ............................................... 196
Hood ................................................................325
Outside rear view mirrors ......................... 142
Adjusting and folding.................................142
Blind Spot Monitor (BSM)......................241
Linked mirror functi on when reversing
............................................................................142
Mirror position memory ...........................134
Outside rear view mirror defoggers269
Outside temperature display .....................79
Overheating .................................................. 394
P
Paddle shift switches .................................... 175
Panic mode ..................................................... 104
Parking brake
Operation ........................................................ 177
Parking brake engaged warning buzzer/
message ........................................................ 177
Warning light .............................................. 369
Parking lights
Light switch .................................................... 183
Replacing light bulb ..................................353
Parking Support Brake fu nction (for static
objects) ......................................................... 232
Indicator............................................................. 75
Warning light .............................................. 368
Warning messages...................................238
PCS (Pre-Collision System)
Function ..........................................................203
PCS switch................................................... 205
Warning light ............................................... 367
Warning message ..................................... 374
Personal lights............................................... 278