2019 LEXUS NX300H engine overheat

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

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

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

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