2022 LEXUS RX450h engine overheat

4227-2. Steps to take in an emergency
not be charged when the shift lever is in N,
shift the shift lever to P when the vehicle is
stopped.
■If “Traction Battery Needs to be Pro-
tected. Shift into P to Restart.” is dis-
played
This message is displayed when the hybrid
battery (traction battery) charge has
become extremely low because the shift
lever has been left in N for a certain amount
of time.
When operating the vehicle, shift to P and
restart the hybrid system.
■If “Shift Is in N Release Accelerator
Before Shifting ” is displayed
Message is displayed when the accelerator
pedal has been depressed and the shift
lever is in N.
Release the accelerator pedal and shift the
shift lever to D or R.
■If “Depress Brake when Vehicle Is
Stopped Hybrid Syst em May Overheat”
is displayed
Message is displayed when the accelerator
pedal is depressed to maintain the vehicle
position when stopped on a upward slope,
etc.
If this continues, th e hybrid system may
overheat.
Release the accelerator pedal and depress
the brake pedal.
■If “Power Turned Off to Save Battery” is
displayed
This message is disp layed when the power
was cut off due to the automatic power off
function. The next time the hybrid system is
started, increase the engine speed slightly
and maintain it at th at speed for approxi-
mately 5 minutes to recharge the 12-volt
battery.
■If “Headlight System Malfunction Visit
Your Dealer” is displayed
The following systems may be malfunction-
ing. Have the vehicle inspected by your
Lexus dealer immediately.
●The LED headlight system
●AFS (Adaptive Front-li ghting System) (if equipped)
●The automatic headlight leveling system
●Automatic High Beam
■If “Radar Cruise Control Unavailable
See Owner's Manual” is displayed
The dynamic radar cruise control with
full-speed range syst em is suspended tem-
porarily or until the problem shown in the
message is re solved. (causes and coping
methods: P.216)
■If “Radar Cruise Control Unavailable” is
displayed
The dynamic radar cruise control with
full-speed range system cannot be used
temporarily. Use the system when it
becomes available again.
■If a message that indicates the malfunc-
tion of front camera is displayed
The following systems may be suspended
until the problem show n in the message is
resolved. ( P.216, 416)
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●Automatic High Beam
●RSA (Road Sign Assi st) (if equipped)
●Dynamic radar cruise control with
full-speed range
■If a message that indicates the malfunc-
tion of radar sensor is displayed
The following systems may be suspended
until the problem show n in the message is
resolved. ( P.216, 410)
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●Dynamic radar cruise control with
full-speed range
■If “Maintenance Required Soon” is dis-
played (U.S.A. only)
Indicates that all maintenance according to
the driven distance on the maintenance
schedule
* should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-

4467-2. Steps to take in an emergency
“Engine Coolant Temp High Stop in
a Safe Place See Owner’s Manual”
is shown on the multi-information
display
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
WARNING
●Make sure to replace the 12-volt bat-
tery with one designed for this vehicle.
Otherwise, hydrogen gas may enter
the vehicle, possibly causing a fire or
explosion.
●After replacing, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the replaced
12-volt battery. If no t properly installed,
gases (hydrogen) may leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when chargi ng the 12-volt bat-
tery from another ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.83)
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 Stop
in a Safe Place See Owner’s
Manual” or “Hybrid System
Overheated Output power
reduced” is shown on the
multi-information display.
 Steam comes out from under the
hood.
Correction procedures

4487-2. Steps to take in an emergency
Lexus dealer.
If “Hybrid System Overheated Out-
put power reduced” is shown on the
multi-information display
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 (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The 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
coolant is unavailable.
6Start the hybrid system and check if
“Hybrid System Overheated Out-
put power reduced” is shown on
the multi-information 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.
A
B
A
B
C
WARNING
■When inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.

506Alphabetical Index
Fluid ......................................................369, 457
Parking brake ................................................193
Regenerative braking ................................. 67
Warning light ................................................ 410
Brake assist .................................................... 278
Break-in tips.....................................................163
Brightness control Instrument panel light control ................ 87
BSM (Blind Spot Monitor)....................... 246
Buzzer Hands off steering wheel warning (LTA)......................................................................... 232
C
Care Exterior .......................................................... 350
Interior ............................................................. 353
Seat belts........................................................ 353
Wheels and wheel ornaments........... 350
Cargo capacity..................................... 167, 170
Cargo hooks ................................................. 324
Cargo net hooks .......................................... 324
Center Display ............................................. 294
Chains .............................................................. 287
Child restraint system Fixed with a LATCH system .................. 54
Fixed with a seat belt...................................50
Front passenger occupant classification system ............................................................. 39
Points to remember .................................... 45
Riding with children ..................................... 45
Types of child restraint system installation method ........................................................... 46
Using an anchor bracket .......................... 57
Child safety 12-volt battery precautions ....... 372, 445
Airbag precautions...................................... 36
Child restraint system................................. 46
Heated steering wheel and seat heater precautions.................................................. 312
How your child should wear the seat belt .............................................................................27 Moon roof precautions............................ 155
Panoramic moon roof precautions ... 158
Power back door precautions ............... 113
Power window lock switch .................... 153
Power window precautions .................. 152
Rear door child-protectors ..................... 112
Seat belt extender prec
autions.............. 27
Seat belt precautions .................................. 45
Child-protectors............................................. 112
Cleaning Exterior........................................................... 350
Interior .............................................................353
Radar sensor .................................................. 212
Seat belts ........................................................353
Wheels and wheel ornaments ........... 350
Clock ....................................................... 83, 338
Coat hooks..................................................... 338
Coin box.......................................................... 322
Compass ......................................................... 346
Condenser ..................................................... 368
Console box .................................................. 320
Cooling system............................................. 367 Engine overheating...................................446
Hybrid system overheating ................. 448
Cornering lights ...........................................200 Replacing light bulbs................................393
Cruise control Dynamic radar cruise control with full-speed range ......................................236
Cup holders .....................................................321
Current fuel consumption .......................... 90
Curtain shield airbags .................................. 30
Customizable features ...............................472
D
Daytime running light system .................. 198
Defogger Outside rear view mirrors.................... 300
Rear window ............................................... 300
Windshield ................................................... 300
Differential Rear differential oil.....................................457

508Alphabetical Index
If the fuel filler door cannot be opened.........................................................................438
If the hybrid system will not start ........ 436
If the vehicle is submerged or water on the road is rising......................................403
If you have a flat tire .................................. 424
If you lose your keys.................................438
If you think something is wrong .........409
If your vehicle becomes stuck............. 449
If your vehicle has to be stopped in an
emergency ................................................ 402
If your vehicle needs to be towed .....405
If your vehicle overheats ........................ 446
Energy monitor .....................................99, 100
Engine ACCESSORY mode .............................. 185
Compartment .............................................365
Engine switch.................................................182
Hood................................................................ 363
How to start the hybrid system ............182
Identification number ............................... 453
If the hybrid system will not start ........ 436
If your vehicle has to be stopped in an
emergency ................................................ 402
Ignition switch (power switch) ..............182
Overheating................................................. 446
Power switch .................................................182
Tachometer ..................................................... 83
Engine coolant Capacity .........................................................456
Checking ....................................................... 367
Preparing and checking before winter.........................................................................286
Engine coolant temperature gauge ....... 83
Engine oil Capacity .........................................................455
Checking .......................................................365
Preparing and checking before winter.........................................................................286
Warning light ...................................................411
Engine oil maintenance data .................. 367 Engine switch (power switch) ..................182
If your vehicle has to be stopped in an emergency .................................................402
EPS (Electric Power Steering) .............. 279 Warning light .................................................413
EV drive mode................................................187
EV indicator .......................................................67
Event data recorder (EDR) ........................... 8
F
Flat tire Tire pressure warning system ............. 376
Vehicles with a spare tire....................... 424
Floor mats .......................................................... 24
Fluid Brake ................................................................ 457
Hybrid transmission.................................. 457
Washer .......................................................... 369
Fog lights Switch...............................................................204
Footwell light ...................................................315
Front automatic air conditioning system .......................................................................... 298
Front fog lights Replacing light bulbs................................393
Front passenger footwell hooks ............ 340
Front passenger occupant classification system .............................................................. 39
Front seats Adjustment ......................................................129
Cleaning .........................................................353
Correct driving posture ............................ 25
Driving position memory ........................ 140
Head restraints..............................................143
Memory recall function.............................. 141
Power easy access system .................... 140
Seat heaters ....................................................312
Seat position memory .............................. 140
Seat ventilators ..............................................312
Front side marker light Light switch .................................................... 198
Replacing light bulbs................................393

510Alphabetical Index
High voltage components ....................... 69
Hybrid system precautions ..................... 69
If the hybrid system will not start ........ 436
Overheating.................................................448
Power (ignition) switch.............................182
Regenerative braking ................................. 67
Starting the hybrid system.......................182
Hybrid System Indicator......................85, 99
Hybrid transmission..................................... 189 M mode ............................................................. 191
Paddle shift switches .........................190, 191
Hybrid vehicle driving tips ....................... 284
I
I/M test ............................................................ 360
Identification Engine ............................................................. 453
Vehicle ............................................................ 452
If your vehicle has to be stopped in an
emergency .................................................. 402
Ignition switch (power switch) .................182 Auto power off function .......................... 185
Changing the power switch modes . 185
If your vehicle has to be stopped in an
emergency ................................................ 402
Immobilizer system......... ................................73
Indicators ........................................................... 80
Initialization Items to initialize .........................................485
Maintenance ....................................356, 367
Power windows............................................. 151
Tire pressure warning system ............. 378
Inside rear view mirror ................................ 147
Instrument panel light control ................... 87
Interior lights....................................................315 Front interior light ........................................315
Rear interior light .........................................315
Intuitive parking assist.....................250, 252 Function .......................................................... 252
Warning message..................................... 254
J
JackPositioning a floor jack ............................363
Vehicle-equipped jack ...........................425
Jack handle .................................................... 425
Jam protection function Electronic sunshade ...................................157
Moon roof ...................................................... 154
Panoramic moon roof ...............................157
Power back door.......................................... 119
Power windows ............................................. 151
Rear seats ....................................................... 130
K
Keyless entrySmart access system with push-button start ................................................................. 125
Wireless remote control ......................... 107
Keys Battery-saving function.............................126
Electronic key ............................................... 106
If the electronic key does not operate properly .......................................................439
If you lose your keys ................................ 438
Key number plate ....................................... 106
Keyless entry ....................................... 107, 125
Mechanical key ............................................ 106
Power switch................................................. 182
Replacing the battery .............................. 386
Warning buzzer .......................................... 125
Wireless remote control ......................... 107
Knee airbags .................................................... 30
L
Lane Tracing Assist (LTA) Operation ...................................................... 225
Warning messages................................... 233
Language (multi-infor mation display) ... 92
LATCH anchors ............................................. 54

512Alphabetical Index
Energy monitor............................................ 100
G-force................................................................ 91
LTA (Lane Tracing Assist).................... 230
Menu icons ...................................................... 89
Meter control switches .............................. 89
Navigation system-linked display ........ 92
Pop-up display...............................................88
Settings .............................................................. 92
Suggestion function..................................... 93
Tire pressure ................................................ 376
Units ...................................................................... 91
Warning message..................................... 420
N
Navigation system-linked display....92, 98
Noise from under vehicle ...............................6
O
“ODO TRIP” switch ...................................... 87
Odometer ......................................................... 87
Odometer and trip meter displayDisplay items ................................................... 87
“ODO TRIP” switch .................................... 87
Pop-up display............................................... 87
Oil Engine oil .......................................................455
Rear differential oil .................................... 457
Opener Fuel filler door..............................................209
Hood................................................................ 363
Outer foot lights Location............................................................315
Outside door handle lights........................315
Outside rear view mirrors Adjustment..................................................... 148
BSM (Blind Sport Monitor) ................. 246
Folding ..............................................................149
Linked mirror function when reversing.......................................................................... 148
Mirror position memory.......................... 140
Outside rear view mirror defoggers300 RCTA function ............................................259
Outside temperature..... ............................... 83
Overheating .................................................. 446
P
Paddle shift switches ........................... 190, 191
Panic mode ......................................................107
Panoramic moon roof Jam protection function ............................157
Operation ....................................................... 156
Parking assist sensors (intuitive parking assist) ............................................................. 252
Parking brake Operation ....................................................... 193
Parking brake engaged warning buzzer........................................................................... 195
Warning light ................................................ 416
Warning message ...................................... 195
Parking lights Light switch .................................................... 198
Replacing light bulbs................................393
Parking Support Brake function (for rear-crossing vehicles) ...........................274 Function .......................................................... 274
Parking Support Brake function (static objects) ........................................................... 271 Function ............................................................ 271
PCS (Pre-Collision System) Function ........................................................... 218
PCS OFF switch ........................................220
Warning light ................................................ 416
Personal lights.................................................315
PKSA (Parking Support Alert) .............. 250
PKSB (Parking Support Brake)............. 265 Warning message ..................................... 270
Power back door ............................................ 113 Hands Free Power Back Door ............. 116
Smart access system with push-button start ................................................................... 114
Power control unit.......................................... 69
Power control unit coolant Capacity ........................................................ 456

516Alphabetical Index
Installing tire pressure warning valves and transmitters .......................................377
Registering ID codes ............................... 379
Warning light ................................................. 414
Tires Chains ............................................................. 287
Checking ....................................................... 374
If you have a flat tire .................................. 424
Inflation pressure....................................... 380
Information .................................................... 463
Replacing ....................................................... 424
Rotating tires ................................................ 376
Size....................................................................458
Snow tires ......................................................286
Spare tire........................................................ 424
Tire inflation pressure display function......................................................................... 376
Tire pressure warning system ............. 376
Warning light ................................................. 414
Tools.................................................................. 425
Top tether strap................................................57
Total load capacity ...................................... 452
Towing Dinghy towing ................................................ 181
Emergency towing ...................................405
Towing eyelet .............................................. 407
Trailer towing ...................................................171
TRAC (Traction Control) ........................ 279
Traction battery (hybrid battery) Hybrid battery (traction battery) air vents.............................................................................. 71
Location............................................................. 69
Specification ................................................. 454
Warning message......................................... 72
Traction Control (TRAC) ........................ 279
Traction motor (electric motor) ............... 66
Trailer Sway Control.................................. 279
Trailer towing ................................................... 171
Transmission Driving mode select switch .................. 276
Hybrid transmission .................................. 189
M mode ............................................................. 191 Paddle shift switches ........................ 190, 191
Trip meters ........................................................ 87
Turn signal lights Replacing light bulbs................................393
Turn signal lever ...........................................192
Wattage ......................................................... 460
U
USB charging ports.................................... 329
V
Vanity lights.................................................... 340Wattage ......................................................... 460
Vanity mirrors ............................................... 340
VDIM (Vehicle Dynamics Integrated Man- agement)...................................................... 279
Vehicle data recording ....................................7
Vehicle Dynamics Integrated Manage- ment (VDIM).............................................. 279
Vehicle identification number ................ 452
Vehicle Stability Control (VSC) ........... 278
Ventilators (seat ventilators).....................312
VSC (Vehicle Stability Control) ........... 278
W
Warning buzzers
Approach warning.................................... 242
Brake Override System ...........................412
Door lock .......................................................... 110
Downshifting ................................................... 191
Drive-Start Control.....................................412
Electric power steering.............................413
Hands off steering wheel warning (LTA).......................................................................... 232
High coolant temperature...................... 410
Hybrid system overheat ............................ 411
Intuitive parking assist ................... 258, 415
Low engine oil pressure ............................ 411
LTA (Lane Tracing Assist)225, 228, 414
Open door ....................................................... 112