2016 LEXUS RX450H heating

380 4-5. Using the driving support systems
RX450h_U_OM0E013U ■
Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air condi-
tioning system to enhance fuel efficiency. To improve air conditioning performance,
adjust the fan speed or turn off Eco drive mode. ■
Automatic deactivation of sport mode and customized mode
If the power switch is turned off after driv ing in sport mode or customized mode, the
drive mode will be changed to normal mode. ■
Driving mode pop-up display (12.3-inch display only)
When the driving mode is changed, the selected driving mode will be temporarily dis-
played on the side display. (  P. 4 0 2 )

3854-5. Using the driving support systems
4
Driving
RX450h_U_OM0E013U ■
Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases. However, when TRAC, VS C and Trailer Sway Control systems are
turned off, the systems will not turn on even 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. ■
Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:●
The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline). ●
The vehicle is stopped. ●
The accelerator pedal is not depressed. ●
The parking brake is not engaged. ■
Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations: ●
The shift lever is moved to P or N. ●
The accelerator pedal is depressed. ●
The parking brake is engaged. ●
Approximately 2 seconds elapse after the brake pedal is released.
WA R N I N G ■
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 operat ing may exceed that of normal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:●
When driving on dirt, gravel or snow-covered roads ●
When driving with tire chains ●
When driving over bumps in the road ●
When driving over roads with potholes or uneven surfaces ■
TRAC may not operate effectively when
Directional control and power may not be achievable while drivin g on slippery road
surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.

412 5-2. Using the air conditio ning system and defogger
RX450h_U_OM0E013U ■
Windshield fog detection function
When automatic mode is se t, the humidity sensor (  P. 413) detects fog on the wind-
shield and controls the air conditioning 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 ai r mode. This is effective in preventing out-
side air from entering the vehicle interi or. 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 performa nce, perform the following operations
• Adjust the fan speed
• Turn off Eco drive mode ■
Ventilation and air conditioning odors ●
To let fresh air in, set the air conditio ning system to the outside air mode.●
During use, various odors from inside and outside the vehicle may enter into and accu-
mulate in the air conditioning system. This may then cause odor to be emitted from the
vents. ●
To reduce potential odors from occurring:
• It is recommended that the air conditioning system be set to outside air mode prior
to turning the vehicle off.
• The start timing of the blower may be dela yed for a short period of time immediately
after the air conditioning system is started in automatic mode.■
Air conditioning filter
 P. 5 0 1 ■
Customization
Some functions can be customized (  P. 6 0 7 )

414 5-2. Using the air conditio ning system and defogger
RX450h_U_OM0E013UHeated steering wheel 
/seat heaters/seat ventila-
tors
 : If equippedHeated steering wheel and seat heater s heat the side grips of the steering
wheel and seats, respectively. Seat ventilators maintain good airflow by blow-
ing air from the seats. WA R N I N G ●
Care should be taken to prevent injury if anyone in the following categories comes in
contact with the steering wheel an d seats when the heater is on:
• Babies, small children, the elderly, the sick and the physically challenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (s leeping 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 uneven 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.

574 7-2. Steps to take in an emergency
RX450h_U_OM0E013U ■
“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. 97) enters the
red zone, or a loss of hybrid system po wer 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

643Alphabetical index
RX450h_U_OM0E013U Coolant
Capacity ................................................ 587
Checking................................................ 479
Preparing and checking
before winter ................................... 390
Cooling system ..................................... 479
Hybrid system overheating ..........574
Cornering lights .................................... 252
Cruise control
Cruise control..................................... 335
Dynamic radar cruise control...... 323
Dynamic radar cruise control
with full-speed range ....................... 311
Cup holders ............................................ 423
Curtain shield airbags ........................... 39
Customizable features ....................... 607
Customized mode ................................377 Daytime running light system.......... 253
Defogger
Outside rear view mirrors ............409
Rear window ........................................409
Windshield............................................409
Differential .............................................. 588
Dimension ............................................... 582
Dinghy towing ......................................... 231
Display
Dynamic radar cruise control ..... 323
Dynamic radar cruise control
with full-speed range .......................311
Energy monitor..................................... 124
LDA (Lane Departure Alert
with steering control) ...................306
LKA (Lane-Keeping Assist)......... 297
Multi-information display.................102
Warning messages .......................... 543
Do-it-yourself maintenance............... 471
Doors
Automatic door locking and
unlocking system..............................139
Door lock................................................ 138
Outside rear view mirrors ............. 185
Power back door ................................ 142
Rear door child-p rotectors ............139
Side doors ...............................................136
Side windows ....................................... 189
Drive information ...................................106
Drive-start control .................... 205, 242
Driver’s seat belt reminder light .... 538
Driver’s seat position memory.......... 174 D

645Alphabetical index
RX450h_U_OM0E013U Engine
ACCESSORY mode...................... 233
Compartment ......................................475
Engine switch ....................................... 232
Hood ........................................................ 473
How to start the hybrid
system .................................................. 232
Identification number ...................... 583
If your vehicle has to be
stopped in an emergency ..........529
Ignition switch (power switch) .... 232
Overheating .........................................574
Power switch........................................ 232
Engine coolant
Capacity ................................................ 587
Checking................................................ 479
Preparing and checking
before winter ................................... 390
Engine coolant temperature
gauge .........................................................97
Engine oil
Capacity ................................................ 585
Checking................................................ 476
Preparing and checking
before winter ................................... 390
Engine oil maintenance data ........... 478
Engine switch ......................................... 232
Enhanced VSC ...................................... 381
EPS
(Electronic Power Steering) ......... 381
Warning light .......................................537
EV drive mode....................................... 237
EV indicator ............................................... 78
Event data recorder (EDR) .................... 11 Flat tire ...................................................... 549
Floor mats................................................... 28
Fluid
Brake....................................................... 588
Transmission ....................................... 588
Washer ................................................... 482
Fog lights
Replacing light bulbs .........................513
Switch ...................................................... 259
Front passenger footwell
hooks.......................................................442
Front passenger occupant
classification system ............................. 51
Front passenger’s seat belt
reminder light ..................................... 538
Front seat heaters .................................. 415
Front seats ................................................. 164
Adjustment..............................................164
Cleaning................................................. 462
Correct driving posture .................... 30
Driving position memory................. 174
Head restraints ..................................... 179
Power easy access system ............. 174
Seat heaters ............................................415
Seat position memory ....................... 174
Front side marker lights
Light switch............................................. 251
Replacing light bulbs .........................513
Wattage ................................................ 590 F

647Alphabetical index
RX450h_U_OM0E013U Horn .............................................................. 181
HUD (Head-up display) ....................... 118
Humidity sensor ......................................413
Hybrid battery air vent ............................81
Hybrid battery (traction battery)
Location .................................................... 80
Specification ........................................ 585
Hybrid system ............................................76
Emergency shut off system............... 81
Energy monitor/
consumption screen .......................124
EV drive mode.................................... 237
High voltage components .............. 80
Hybrid System Indicator .................100
Hybrid system precautions............. 80
Hybrid vehicle driving tips.............387
If the hybrid system will not
start ......................................................... 561
Overheating .........................................574
Power (ignition) switch ................... 232
Regenerative braking ......................... 78
Starting the hybrid system ............. 232
Vehicle proximity notification
system ..................................................... 77
Hybrid System Indicator..................... 100
Hybrid transmission ............................ 239
If the shift lever cannot be
shifted from P .................................. 563
Paddle shift switches ............. 240, 241
S mode ......................................................241 I/M test ......................................................470
Identification
Engine .....................................................583
Vehicle ....................................................583
Ignition switch (power switch) .........232
Illuminated entry system ................... 420
Immobilizer system ................................ 85
Indicators .....................................................92
Initialization
Engine oil maintenance data ....... 478
Items to initialize ...................................619
Power back door ............................... 150
Tire pressure warning
system ................................................. 488
Inside rear view mirror.........................183
Instrument panel light control .............99
Interior lights ............................................ 417
Switch ........................................................418
Wattage ................................................ 590
Intuitive parking assist ........................ 339
Jack
Positioning a floor jack.................... 474
Vehicle-equipped jack .................. 550
Jack handle ............................................. 550
Jam protection function
Electronic sunshade.......................... 198
Moon roof ...............................................194
Panoramic moon roof...................... 198
Power back door opener
and closer ........................................... 150
Power windows................................... 190 I
J