overheating LEXUS RX450H 2020 Owners Manual

892. Instrument cluster
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Instrument cluster
RX350/RX350L_U
■The meters and display illuminate when
The engine switch is in IGNITION ON mode.
■Brightness of the meters (day mode and night mode)
The brightness of the meters is changed between day mode and night mode.
●Day mode: When the tail lights are off or when the tail lights are on but the surrounding
area is bright
●Night mode: When the tail lights are on and the surrounding area is dark
■Outside temperature display
●In the following situations, the correct outside temperature may not be displayed, or the
display may take longer than normal to change:
• When stopped, or driving at low speeds (less than 12 mph [20 km/h])
• When the outside temperature has changed suddenly (at the entrance/exit of a garage, tunnel, etc.)
●When “ ” or “E” is displayed, the sy stem may be malfunctioning.
Take your vehicle to your Lexus dealer.
■Clock settings screen (vehicles with a navigation system only)
If the clock adjustment screen is displayed continuously when attempting to change the
clock settings, the system may be malfunctioning.
Have the vehicle inspected by your Lexus dealer.
■Customization
Some functions can be customized. ( P. 97)
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator needle of the tachometer enter the red zone, which indicates
the maximum engine speed.
●The engine may be overheating if the engine coolant temperature gauge is in the red
zone (H). In this case, immediately stop the vehicle in a safe place, and check the
engine after it has cooled completely. ( P. 692)

2244-1. Before driving
RX350/RX350L_U
●To maintain engine braking efficien cy and charging system performance
when using engine braking, do not put th e transmission in D. If in the M or S
mode, the transmission shift range po sition must be in 6 or lower. (P. 240)
●Instability happens more fr equently when descending steep or long downhill
grades. Before descending, slow down and downshift. Do not make sudden
downshifts while descending st eep or long downhill grades.
●Avoid holding the brake pedal down too long or applying the brakes too fre-
quently. This could cause the brakes to overheat and result in reduced braking
efficiency.
●Due to the added load of the trailer, yo ur vehicle’s engine may overheat on hot
days (at temperatures over 85 F [30 C]) when driving up a long or steep
grade. If the engine coolant temperat ure gauge indicates overheating, imme-
diately turn off the air conditioning (if in use), pull your vehicle off the road and
stop in a safe spot. ( P. 692)
●Always place wheel blocks under both the vehicle’s and the trailer’s wheels
when parking. Put the transmission in P and apply the parking brake. Avoid
parking on a slope, but if unavoidable, do so only after performing the follow-
ing:
Apply the brakes and keep them applied.
Have someone place wheel blocks under both the vehicle’s and trailer’s
wheels.
When the wheel blocks are in place, release the brakes slowly until the
blocks absorb the load.
Shift into P and apply the parking brake.
Turn off the engine.
●When restarting afte r parking on a slope:
With the transmission in P, start the en gine. Be sure to keep the brake pedal
depressed.
Shift into a forward gear. If reversing, shift into R.
If the parking brake is in manual mode, release the parking brake.
( P. 248)
Release the brake pedal, and slowly pull or back away from the wheel
blocks. Stop and apply the brakes.
Have someone retrieve the blocks.
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2334-2. Driving procedures
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Driving
RX350/RX350L_U
■Auto power off function
If the vehicle is left in ACCESSORY mode for more than 20 minutes or IGNITION ON
mode (with the engine not running) for more than an hour with the shift lever in P, the
engine switch will automatically turn off. However, this function cannot entirely prevent
battery discharge. Do not leave the vehicle with the engine switch in ACCESSORY or
IGNITION ON mode for long periods of time when the engine is not running.
■Electronic key battery depletion
P. 122
■Conditions affe cting operation
 P. 148
■Note for the entry function
P. 149
■If the engine does not start
●The engine immobilizer system ma y not have been deactivated. (P. 74)
Contact your Lexus dealer.
●Check that the shift lever is se curely set in P. The engine may not start if the shift lever is
displaced out of P. “To Start Vehicle, Put Sh ift Lever into P” will be displayed on the
multi-information display.
■Steering lock
After turning the engine switch off and opening and closing the doors, the steering wheel
will be locked due to the steering lock func tion. Operating the engine switch again auto-
matically cancels the steering lock.
■When the steering lock cannot be released
■Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, operation of the motor may be sus-
pended if the engine is turned on and off repeat edly in a short period of time. In this case,
refrain from operating the engine switch. After about 10 seconds, the steering lock
motor will resume functioning.
■When “Access System with Elec. Key Malf unction See Owner’s Manual” is displayed
on the multi-information display
The system may be malfunctio ning. Have the vehicle inspected by your Lexus dealer
immediately. “Steering Wheel Lock Press Engine Switch
while Turning Wheel” w ill be displayed on the
multi-information display.
Check that the shift leve r is in P. Press the
engine switch shortly and firmly while turning
the steering wheel left and right.

2484-2. Driving procedures
RX350/RX350L_U
The parking brake can be set and released manually. Sets the parking brake
The parking brake indicator light and
parking brake light will turn on.
Pull and hold the parking brake switch if
an emergency occurs and it is necessary
to operate the parking brake while driv-
ing.
Releases the parking brake
Operate the parking brake switch while
depressing the brake pedal. Make sure
that the parking brake indicator light
and parking brake light turn off.
If the parking brake indicator light and
parking brake lamp flashes, operate the
switch again. ( P. 654)
■Parking the vehicle
 P. 202
■Parking brake operation
●When the engine switch is not in IGNITION ON mode, the parking brake cannot be
released using the parking brake switch.
●When the engine switch is not in IGNITION ON mode, automatic mode (automatic
brake setting and releasing) is not available.
■If “Parking Brake Overheated Parking Brak e Unavailable” is displayed on the multi-
information display
If the parking brake is operated repeatedly over a short period of time, the system may
restrict operation to prevent overheating. If this happens, refrain from operating the
parking brake. Normal operation wi ll return after about 1 minute.
■If “EPB Activation Stopped Incompletely” or “Parking Brake Unavailable” is displayed
on the multi-information display
Operate the parking brake switch. If the message does not disappear after operating the
switch several times, the system may be ma lfunctioning. Have the vehicle inspected by
your Lexus dealer immediately.
■Parking brake operation sound
When the parking brake operates, a motor so und (whirring sound) may be heard. This
does not indicate a malfunction.
Manual mode
U.S.A. Canada
Parking
brake light
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3824-5. Using the driving support systems
RX350/RX350L_U
■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 engine swit ch 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, automatic 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 engine off. The EPS system should return to normal
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 and power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC/VSC system is op erating. Drive the vehicle carefully in con-
ditions where stability and power may be lost.

5216-2. Using the air conditioning system and defogger
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Interior features
RX350/RX350L_U
Heated steering wheel/seat heaters/seat ventila-
tors


: If equipped
Heated steering wheel and seat heaters heat the side grips of the steering
wheel and seats, respectively. Seat ventilators maintain good ventilation using
a fan built into 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 physically 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 battery discharge, do not us e the functions when the engine is off.

6928-2. Steps to take in an emergency
RX350/RX350L_U
Stop the vehicle in a safe place and turn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down
sufficiently, insp ect the hoses and
radiator core (radiator) 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 cap
If your vehicle overheats
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 86) enters the
red zone, or a loss of engine power is experienced. (For example, the vehi-
cle speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●Steam comes out from under the hood.
Correction procedures
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760Alphabetical index
RX350/RX350L_U
Child-protectors..................................... 127
Cleaning......................................... 576, 581 Aluminum wheels .............................. 577
Exterior....................................................576
Interior ...................................................... 581
Seat belts ............................................... 582
Clock .................................................86, 544
Coat hooks.............................................. 556
Compass .................................................. 564
Condenser .............................................. 599
Console box ...........................................530
Consumption screen ..................... 94, 114 Coolant
Capacity................................................. 702
Checking .............................................. 598
Preparing and checking before winter ....................................384
Cooling system ..................................... 598 Engine overheating .......................... 692
Cornering lights.................................... 253
Cruise control Dynamic radar cruise control with full-speed range .................. 300
Cup holders.............................................. 531
Curtain shield airbags ............................ 37
Customizable features ....................... 722
Customized mode................................373

762Alphabetical index
RX350/RX350L_U
Eco drive mode ..................................... 373
Eco Driving Indicator........................... 105
EDR (Event data recorder) ...................10
Electric Power Steering (EPS) ....... 378Warning light ...................................... 655
Electronic key ......................................... 120 Battery-saving function .....................147
If the electronic key does not operate properly............................ 684
Replacing the battery .......................623
Emergency flashers ............................. 644
Emergency, in case of If a warning buzzer sounds.......... 654
If a warning light turns on.............. 654
If a warning message is displayed.............................................. 661
If the battery is discharged ........... 687
If the electronic key does not operate properly............................ 684
If the engine will not start............... 682
If you have a flat tire ......................... 666
If you lose your keys .................. 121, 123
If you think something is wrong ...................................................652
If your vehicle becomes stuck .... 695
If your vehicle has to be stopped in an emergency .. 645
If your vehicle needs to be towed................................................... 646
If your vehicle overheats ................692 Engine
ACCESSORY mode ..................... 232
Compartment ..................................... 594
Engine switch ........................................ 231
Hood........................................................ 592
How to start the engine.................... 231
Identification number.......................700
If your vehicle has to be stopped in an emergency.......... 645
Ignition switch (engine switch) ..... 231
Overheating......................................... 692
Engine coolant Capacity................................................. 702
Checking .............................................. 598
Preparing and checking before winter ....................................384
Engine coolant temperature gauge ........................................................ 86
Engine immobilizer system .................. 74
Engine oil Capacity.................................................700
Checking ...............................................595
Preparing and checking before winter ....................................384
Engine oil maintenance data ............597
Engine switch ........................................... 231
Enhanced VSC ..................................... 378
EPS (Electronic Power Steering) ........ 378 Warning light .......................................655
Event data recorder (EDR)................... 10
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768Alphabetical index
RX350/RX350L_U
Odometer ................................................ 104
OilEngine oil............................................... 700
Rear differential oil .............................703
Transfer oil .............................................703
Opener Fuel filler door ........................................ 271
Hood ........................................................592
Power back door .................................. 131
Outside rear view mirrors ................. 184 Adjusting and folding........................ 184
Blind Spot Monitor (BSM)............. 313
Linked mirror function when reversing .............................................. 185
Mirror position memory ................... 172
Outside rear view mirror defoggers ............................................ 513
Outside temperature display ............. 86
Overheating ........................................... 692
Paddle shift switches ................. 241, 242
Panic mode ................................................ 121
Panoramic moon roof ......................... 195 Jam protection function ................... 196
Operation ............................................... 195 Parking brake ......................................... 247
Parking brake engaged warning buzzer/message ......... 249
Warning light .......................................655
Parking lights Light switch........................................... 252
Replacing light bulbs .......................630
PCS (Pre-Collision System).............. 281 Warning light .......................................656
Personal lights ....................................... 526
Power back door ...................................130 Touchless power back door.......... 132
Wireless remote control................. 130
Power back door opener and closer .......................................................130
Power easy access system ................. 172
Power outlets ........................................... 551
Power steering (Electric Power Steering system)................................ 378 Warning light .......................................655
Power windows Door lock linked window operation ............................................. 189
Jam protection function................... 188
Operation................................................187
Window lock switch ..........................187
Pre-Collision System (PCS).............. 281 Warning light .......................................656
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