2018 LEXUS RX450h heating

386 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85U■
ECB operating sound
ECB operating sound may be heard in the followi ng cases, but it does not indicate that a
malfunction has occurred. ●
Operating sound heard from the engine compartment when the brake pedal is oper-
ated. ●
Motor sound of the brake system heard from the front part of the vehicle when the
driver’s door is opened. ●
Operating sound heard from the engine compartment when one or two minutes
passed after the stop of the hybrid system. ■
EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction. ■
Automatic reactivation of TRAC, Tr ailer Sway Control and VSC systems
After turning the TRAC, Trailer Sway Contro l and VSC systems off, the systems will be
automatically re-enabled in the following situations: ●
When the power switch is turned off ●
If only the TRAC system is turned off, the TRAC will turn on when vehicle speed
increases
If both the TRAC and VSC systems are turned off, au tomatic re-enabling will not
occur when vehicle speed increases. ■
Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result . Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor-
mal within 10 minutes.
WARNING ■
The ABS does not operate effectively when ●
The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road). ●
The vehicle hydroplanes while driving at high speed on wet or slick roads.■
Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehi cle’s stopping distance . Always maintain a
safe distance from the vehicle in front of you, especially in the following situations: ●
When driving on dirt, grav el or snow-covered roads●
When driving with tire chains ●
When driving over bumps on the road ●
When driving over roads with potholes or uneven surfaces■
TRAC/VSC may not operate effectively when
Directional control an d power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC/VSC system is op erating. Drive the vehi cle carefully in con-
ditions where stability and power may be lost.

5196-2. Using the air conditioning system and defogger
RX450h_RX450hL _U_OM48F85U 6
Interior features ■
When the outside temperature exceeds 75 ° F (24 ° C) and the air conditioning system
is on ●
In order to reduce the air co nditioning power consumption, the air conditioning system
may switch to recirculated air mode automatically.
This may also reduce fuel consumption. ●
Recirculated air mode is selected as a default mode when the power switch is turned to
ON mode. ●
It is possible to switch to outside air mode at any time by pressing the outside/recircu-
lated air mode button. ■
Automatic mode for air intake control
In automatic mode, the system detects exhaust gas and other pollutants and automati-
cally switches between outside air and recirculated air modes.
When the dehumidification function is off, and the fan is operating, turning automatic
mode on will activate the dehumidification function. ■
Fogging up of the windows ●
The windows will easily fog up when the humidity in the vehicle is high. Selecting “A/C”
will dehumidify the air from the outlets and defog the windshield effectively. ●
If you turn “A/C” off, the windows may fog up more easily. ●
The windows may fog up if the recirculated air mode is used. ■
Windshield fog detection function
When automatic mode is set, the humidity sensor ( → P. 521) detects fog on the wind-
shield and controls the air cond itioning system to prevent fog.■
Outside/recirculated air mode ●
When driving on dusty roads such as tunnels or in heavy traffic, set the outside/recircu-
lated air mode button to the recirculated air mode. This is effective in preventing out-
side air from enteri ng the vehicle interior. During cooling operation, setting the
recirculated air mode will also cool the vehicle interior effectively. ●
Outside/recirculated air mode may automa tically switch depending on the tempera-
ture setting or the inside temperature. ■
When the outside temperature is low
The dehumidification function may not operate even when “A/C” is selected. ■
Operation of the air conditioning system in Eco drive mode ●
In the Eco drive mode, the air conditioning sy stem is controlled as follows to prioritize
fuel efficiency
• Engine speed and compressor operation controlled to restrict heating/cooling
capacity
• Fan speed restricted when automatic mode is selected ●
To improve air conditioning performanc e, perform the following operations:
• Adjust the fan speed
• Turn off Eco drive mode

5256-2. Using the air conditioning system and defogger
RX450h_RX450hL _U_OM48F85U 6
Interior features
Heated steering wheel ∗
/seat heaters ∗
/seat ventila-
tors ∗
∗ : If equippedHeated steering wheel and seat heaters heat the side grips of the steering
wheel and seats, respectively. Seat ventilators maintain good airflow by blow-
ing air from the seats. WARNING ●
Care should be taken to prevent injury if anyone in the following categories comes in
contact with the steering wheel and seats when the heater is on:
• Babies, small children, the elderly, the sick and the ph ysically challenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs, cold
remedies, etc.) ●
Observe the following precautions to prevent minor burns or overheating:
• Do not cover the seat with a blanket or cushion when using the seat heater.
• Do not use seat heater more than necessary.
NOTICE ●
Do not put heavy objects that have an unev en surface on the seat and do not stick
sharp objects (needles, nails, etc.) into the seat. ●
To prevent 12-volt battery discharge, do not use the functions when the hybrid system
is off.

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