2018 LEXUS RX450h overheating

702 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the hybrid system.
If you see steam: Carefully lift the hood after the steam subsides.
If you do not see steam: Carefully lift the hood.
After the hybrid system has
cooled down sufficiently, inspect
the hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fans If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator capIf your vehicle overheats The following may indicate that your vehicle is overheating. ●
The needle of the engine coolant temperature gauge ( → P. 96) enters the
red zone, or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.) ●
“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” is shown on the
multi-information display. ●
Steam comes out from under the hood.
Correction procedures 1
2
3
1
2
4
1
2
3
4

774 Alphabetical index
RX450h_RX450hL _U_OM48F85UChild-protectors.....................................139
Cleaning.......................................580, 584
Aluminum wheels ............................... 581
Exterior................................................... 580
Interior .................................................... 584
Seat belts ............................................... 585
Clock ................................................ 96, 548
Coat hooks.............................................. 559
Compass .................................................. 567
Condenser .............................................. 602
Console box ........................................... 534
Consumption screen ................. 105, 124
Coolant
Capacity .................................................. 715
Checking................................................. 601
Preparing and checking
before winter ................................... 390
Cooling system ...................................... 601
Hybrid system overheating ..........702
Cornering lights .................................... 259
Cruise control
Dynamic radar cruise control
with full-speed range ................... 306
Cup holders ............................................ 535
Curtain shield airbags ........................... 37
Customizable features ....................... 736
Customized mode ............................... 379 Daytime running light system.......... 260
Defogger
Outside rear view mirrors ..............516
Rear window..........................................516
Windshield..............................................516
Differential ................................................ 716
Dimensions ............................................... 710
Dinghy towing ....................................... 238
Display
Dynamic radar cruise control
with full-speed range ...................306
Energy monitor..................................... 124
LKA (Lane-Keeping Assist)......... 302
Multi-information display.................. 101
Warning messages .......................... 667
Do-it-yourself maintenance............. 593
Doors
Automatic door locking and
unlocking system..............................139
Door lock................................................ 138
Outside rear view mirrors ..............193
Power back door ................................ 142
Rear door child-p rotectors ............139
Side doors ...............................................136
Side windows ........................................196 D

776 Alphabetical index
RX450h_RX450hL _U_OM48F85UEmergency, in case of
If a warning buzzer sounds.......... 660
If a warning light turns on.............. 660
If a warning message is
displayed.............................................667
If the 12-volt battery is
discharged ........................................ 695
If the electronic key does not
operate properly.............................692
If the hybrid system will
not start ............................................... 690
If you have a flat tire ..........................673
If you lose your keys ................ 133, 135
If you think something is
wrong .................................................. 659
If your vehicle becomes
stuck ..................................................... 706
If your vehicle has to
be stopped in an
emergency........................................ 653
If your vehicle needs to be
towed................................................... 654
If your vehicle overheats ................702
Energy monitor ....................................... 124 Engine
ACCESSORY mode ..................... 240
Compartment ..................................... 597
Engine switch ...................................... 239
Hood........................................................595
How to start the hybrid
system .................................................. 239
Identification number......................... 712
If your vehicle has to be
stopped in an emergency..........653
Ignition switch (power switch) .... 239
Overheating......................................... 702
Power switch ....................................... 239
Engine coolant
Capacity................................................... 715
Checking ................................................ 601
Preparing and checking
before winter ....................................390
Engine coolant temperature
gauge .........................................................96
Engine oil
Capacity................................................... 713
Checking .............................................. 598
Preparing and checking
before winter ....................................390
Engine oil maintenance data ........... 600
Engine switch ......................................... 239
Enhanced VSC ..................................... 382
EPS
(Electronic Power Steering) ........ 383
Warning light .........................................661
EV drive mode .......................................244
EV indicator ............................................... 76
Event data recorder (EDR).....................11

778 Alphabetical index
RX450h_RX450hL _U_OM48F85UHands-free system
(for cellular phone) .............................461
Head restraints ....................................... 186
Head-up display....................................... 118
Headlight cleaner................................. 267
Headlights ............................................... 258
Automatic headlight leveling ...... 260
Automatic High Beam .................... 262
Light switch .......................................... 258
Replacing light bulbs ........................637
Wattage ....................................................719
Windshield wiper linked
headlight illumination..................... 261
Heated steering wheel ....................... 526
Heaters
Automatic air conditioning
system ..................................... 507, 522
Heated steering wheel ....................526
Outside rear view mirrors .............. 516
Seat heaters ..............................526, 527
High mounted stoplight
Replacing ...............................................637
Hill-start assist control ........................ 382
Hood .......................................................... 595
Open ....................................................... 595
Hooks
Cargo hooks ....................................... 540
Cargo net hooks ............................... 540
Front passenger footwell
hooks ....................................................557
Grocery bag hooks........................... 541
Retaining hooks (floor mat) ............. 28 Horn.............................................................189
HUD (Head-up display)....................... 118
Humidity sensor...................................... 521
Hybrid battery air vent ........................... 79
Hybrid battery (traction battery)
Location .................................................... 78
Specification ........................................... 713
Hybrid system............................................ 74
Emergency shut off system ..............79
Energy monitor/
consumption screen....................... 124
EV drive mode ................................... 244
High voltage components ............... 78
Hybrid System Indicator ................... 99
Hybrid system precautions ............. 78
Hybrid vehicle driving tips ........... 388
If the hybrid system will not
start....................................................... 690
Overheating......................................... 702
Power (ignition) switch................... 239
Regenerative braking ..........................76
Starting the hybrid system............. 239
Vehicle proximity notification
system ..................................................... 75
Hybrid System Indicator .......................99
Hybrid transmission .............................246
If the shift lever cannot be
shifted from P ...................................250
Paddle shift switches............ 247, 248
S mode.................................................... 248H

782 Alphabetical index
RX450h_RX450hL _U_OM48F85UMoon roof
Door lock linked moon
roof operation ................................... 198
Jam protection function ................... 201
Operation ............................................. 200
MP3 disc.................................................. 433
Multi-information display
AWD Control display ...................... 106
Clock...........................................................96
Drive information ................................ 105
Dynamic radar cruise control
with full-speed range ................... 306
Energy monitor .....................................124
G-force display.................................... 107
Language .................................................. 113
LKA (Lane-Keeping Assist) ........ 302
Outside temperature ..........................96
PCS (Pre - Collision system) ......287
Settings .....................................................108
Suggestion function ............................. 116
Sway warning display ....................... 106
Warning messages...........................667 Navigation system
* Noise from under vehicle ........................8
Odometer .................................................. 115
Oil
Engine oil ................................................. 713
Rear differential oil .............................. 716
Opener
Fuel filler door...................................... 276
Hood........................................................595
Power back door ................................ 143
Outside rear view mirrors .................. 193
Adjusting and folding ........................193
Blind Spot Monitor (BSM) .............319
Linked mirror function
when reversing..................................194
Mirror position memory ................... 181
Outside rear view mirror
defoggers.............................................516
Outside temperature display ..............96
Overheating............................................702 N
O