air condition LEXUS RX450h 2021 Repair Manual

4267-2. Steps to take in an emergency
If the tire pressure warning light comes
on
1 After the temperature of the tires has
lowered sufficiently, check the inflation
pressure of each tire and adjust them to
the specified level.
2 If the warning light does not turn off
even after several minutes have
elapsed, check that the inflation pres-
sure of each tire is at the specified level
and perform initialization. ( P.385)
If the warning light does not turn off several
minutes after the initia lization has been per-
formed, have the vehicle inspected by your
Lexus dealer immediately.
■The tire pressure warning light may
come on due to natural causes
The tire pressure wa rning light may come
on due to natural causes such as natural air
leaks and tire inflation pressure changes
caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with
a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warn-
ing light will not turn off even though the flat
tire has been replaced with the spare tire.
Replace the spare tire with the repaired tire
and adjust the tire inflation pressure. The
tire pressure warning lig ht will go off after a
few minutes.
■Conditions that the tire pressure warn-
ing system may not function properly
 P.383
■Customization
Some functions can be customized.
(  P.480)
WARNING
■If both the ABS and the brake system
warning lights remain on
Stop your vehicle in a safe place immedi-
ately and contact your Lexus dealer.
The vehicle will become extremely
unstable during br aking, and the ABS
system may fail, which could cause an
accident resulting in death or serious
injury.
■When the electric power steering
system warning light comes on
When the light comes on yellow, the
assist to the power st eering is restricted.
When the light comes on red, the assist
to the power steering is lost and handling
operations of the steering wheel become
extremely heavy.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using more
force than usual.
■If the tire pressure warning light
comes on
Be sure to observe the following precau-
tions.
Failure to do so could cause a loss of
vehicle control and result in death or
serious injury.
●Stop your vehicle in a safe place as
soon as possible. Adjust the tire infla-
tion pressure immediately.
●If the tire pressure warning light comes
on even after tire inflation pressure
adjustment, it is prob able that you have
a flat tire. Check the tire s. If a tire is flat,
change it with the spare tire and have
the flat tire repaired by the nearest
Lexus dealer.
●Avoid abrupt maneuvering and brak-
ing.
If the vehicle tires deteriorate, you
could lose control of the steering
wheel or the brakes.

4547-2. 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 not 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 charging 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

4557-2. Steps to take in an emergency
7
When trouble arises
and radiator 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
Radiator cap
5 Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
6
Start the hybrid system and turn the
air conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 If the fans are not operating:
Stop the hybrid system immediately
and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8 Check if “Engine Coolant Temp
High Stop in a Safe Place See
Owner's Manual” 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
A
B
A
B
C
D

4758-1. Specifications
8
Vehicle specifications
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pressure
Tire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Maximum inflation pressureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation pressureCold tire inflation pressure recommended by a
manufacturer
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of hybrid transmis-
sion, power steering, power brakes, power win-
dows, power seats, radio and heater, to the extent
that these items are available as factory-installed
equipment (whether installed or not)
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil
and coolant, and if so equipped, air conditioning
and additional weight optional engine
Maximum loaded vehicle weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight
150 lb. (68 kg) times the number of occupants
specified in the second column of Table 1
* that fol-
lows
Occupant distributionDistribution of occupants in a vehicle as specified in
the third column of Table 1
* below
Production options weight
The combined weight of installed regular produc-
tion options weighing over 5 lb. (2.3 kg) in excess of
the standard items which they replace, not previ-
ously considered in curb weight or accessory
weight, including heavy duty brakes, ride levelers,
roof rack, heavy duty 12-volt battery, and special
trim

4908-2. Customization
■PKSB (Parking Support Brake)* ( P.266)
*:If equipped
■Driving mode select switch ( P.281)
*:If equipped
■Front automatic air conditioning system ( P.304)
*:If equipped
■Seat heaters*/seat ventilators* ( P.318)
*:If equipped
FunctionDefault settingCustomized setting
PKSB (Parking Support Brake)
functionOnOff—O—
FunctionDefault settingCustomized setting
Powertrain control in custom-
ized mode
*NormalPowerO——Eco
Chassis control in customized
mode
*NormalSportO——
Air conditioning operation in
customized mode
*NormalEcoO——
FunctionDefault settingCustomized setting
A/C auto switch operationOnOffO—O
Exhaust gas sensor sensitivity*Standard-3 to 3O—O
FunctionDefault settingCustomized setting
Driver’s seat temperature pref-
erence in automatic modeStandard-2 (cooler) to 2
(warmer)O—O
Front passenger’s seat tem-
perature preference in auto-
matic mode
Standard-2 (cooler) to 2 (warmer)O—O
ABC
ABC
ABC
ABC

513Alphabetical Index
Alphabetical Index
A
A/CAir conditioning filter ...............................390
Front automatic air conditioning system.........................................................................304
Front seat concentr ated airflow mode
(S-FLOW)................................................... 312
Micro dust and pollen filter...................... 311
Rear automatic air conditioning system ...........................................................................315
ABS (Anti-lock Brake System).............. 283 Warning light ............................................... 420
ACA (Active Cornering Assist) ........... 284
Active Cornering Assist (ACA) ........... 284
Adaptive Front-lighting System (AFS)202
Adaptive Variable Suspension System284
AFS (Adaptive Front-lighting System)202
AHB (Automatic High Beam) ............... 203
Air conditioning filter ................................. 390
Air conditioning system Air conditioning filter ...............................390
Front automatic air conditioning system.........................................................................304
Front seat concentr ated airflow mode
(S-FLOW)................................................... 312
Micro dust and pollen filter...................... 311
Rear automatic air conditioning system ...........................................................................315
Airbags Airbag operating conditions................... 33
Airbag precautions for your child ........ 36
Correct driving posture ............................ 25
Curtain shield airbag operating condi- tions .................................................................. 33
Curtain shield airbag precautions ....... 36
Front passenger occupant classification system ............................................................. 39
General airbag precautions ................... 36
Locations of airbags.................................... 30
Modification and disposal of airbags . 38
Side airbag operating conditions ......... 33 Side airbag precautions ............................ 36
Side and curtain shie
ld airbags operating
conditions ...................................................... 33
Side and curtain shield airbags precau- tions .................................................................. 36
SRS airbags......................................................30
SRS warning light.......................................420
Alarm ................................................................... 75 Warning buzzer .......................................... 418
Anchor brackets ..................................... 46, 57
Antennas (smart acc ess system with
push-button start).......................................125
Anti-lock Brake System (ABS).............. 283 Warning light ...............................................420
Approach warning...................................... 244
Armrest............................................................ 342
Assist grips ..................................................... 342
Audio system-linked display ...................... 92
Automatic headlight leveling system ....201
Automatic High Beam .............................. 203
Automatic light control system..............200
Auxiliary boxes ................................... 329, 331
Average fuel economy................................. 90
Average vehicle speed ................................ 90
AWD Control.................................................... 91
B
Back door .......................................................... 113
Back-up light Wattage ......................................................... 468
Back-up lights Replacing light bulbs ...................400, 406
Battery (12-volt battery) Battery checking ........................................ 376
If the 12-volt battery is discharged ....449
Preparing and checking before winter............................................................................291
Warning light ................................................ 419
Battery (traction batter y) ............................ 69
Blind Spot Monitor (BSM)........................247
Bottle holders ................................................ 328

516Alphabetical Index
If the electronic key does not operate properly....................................................... 447
If the fuel filler door cannot be opened ......................................................................... 446
If the hybrid system will not start ........ 444
If the vehicle is trapped in rising water411
If you have a flat tire .................................. 432
If you lose your keys................................. 446
If you think something is wrong ........... 417
If your vehicle becomes stuck............. 457
If your vehicle has to be stopped in an
emergency ................................................. 410
If your vehicle needs to be towed ....... 413
If your vehicle overheats ........................ 454
Energy monitor ..................................... 99, 100
Engine ACCESSORY mode ...............................187
Compartment ............................................... 371
Engine switch................................................ 184
Hood................................................................369
How to start the hybrid system ........... 184
Identification number .................................461
If the hybrid system will not start ........ 444
If your vehicle has to be stopped in an
emergency ................................................. 410
Ignition switch (power switch) ............. 184
Overheating................................................. 454
Power switch ................................................ 184
Tachometer ..................................................... 83
Engine coolant Capacity ......................................................... 464
Checking ....................................................... 373
Preparing and checking before winter........................................................................... 291
Engine coolant temperature gauge ....... 83
Engine oil Capacity ......................................................... 463
Checking ......................................................... 371
Preparing and checking before winter........................................................................... 291
Warning light .................................................419
Engine oil maintenance data .................. 373 Engine switch (power switch) ................. 184
If your vehicle has to be stopped in an emergency .................................................. 410
EPS (Electric Power Steering) .............. 284 Warning light .................................................421
EV drive mode............................................... 189
EV indicator .......................................................67
Event data recorder (E DR) ........................... 8
F
Flat tire
Tire pressure warning system .............382
Vehicles with a spare tire....................... 432
Floor mats .......................................................... 24
Fluid Brake ............................................................... 465
Hybrid transmission................................. 465
Washer ...........................................................375
Fog lights Switch.............................................................. 206
Footwell light ...................................................321
Front automatic air conditioning system .......................................................................... 304
Front fog lights Replacing light bulbs ............................... 400
Front passenger footwell hooks ............ 345
Front passenger occupant classification system .............................................................. 39
Front seats Adjustment ....................................................... 131
Cleaning ........................................................ 359
Correct driving posture ............................ 25
Driving position memory .........................142
Head restraints............................................. 145
Memory recall function.............................143
Power easy access system .....................142
Seat heaters ................................................... 318
Seat position memory ...............................142
Seat ventilators ............................................. 318
Front side marker light Light switch .................................................. 200
Replacing light bulbs ............................... 400

517Alphabetical Index
Front side marker lightsReplacing light bulbs............................... 400
Wattage..........................................................468
Front turn signal lights Replacing light bulbs................... 400, 402
Turn signal lever ...........................................194
Wattage..........................................................468
Fuel Capacity ......................................................... 462
Fuel gauge ....................................................... 83
Information .................................................... 469
Refueling ............................................................211
Type.................................................................. 462
Warning light ................................................. 421
Fuel consumption Average fuel economy .............................. 90
Current fuel consumption........................ 90
Fuel filler door If the fuel filler door cannot be opened......................................................................... 446
Refueling ............................................................211
Fuel gauge ......................................................... 83
Fuses ................................................................. 395
G
Garage door opener ................................. 346
Gauges ............................................................... 83
G-force................................................................. 91
Glove box ....................................................... 326
Glove box light ............................................. 326
Grocery bag hooks .................................... 330
H
Hands Free Power Back Door ................. 116
Head restraints ...............................................145
Headlight aim ................................................ 397
Headlights Adaptive Front-lighting System (AFS)......................................................................... 202
Automatic High Beam system............ 203
Light switch ...................................................200 Replacing light bulbs ............................... 400
Head-up display.............................................. 95 Driving information display area ...........95
HUD (Head-up display) switch ............ 96
Hybrid System Indicator ........................... 99
Navigation system-linked display ........98
Settings............................................................... 97
Heated steering wheel ............................... 318
Heaters Front automatic air conditioning system......................................................................... 304
Heated steering wheel ............................. 318
Outside rear view mirrors.................... 306
Rear automatic air conditioning system
........................................................................... 315
Seat heaters ................................................... 318
High mounted stoplight Replacing light bulbs ............................... 400
High-voltage components ......................... 69
Hill-start assist control ............................... 284
Hood Open............................................................... 369
Hooks Cargo hooks................................................329
Cargo net hooks ........................................329
Coat hooks ...................................................343
Front passenger footwell hooks.........345
Grocery bag hooks................................. 330
Retaining hooks (floor mat) ..................... 24
Horn ................................................................... 148
HUD (Head-up display) switch ................ 96
Hybrid battery (traction battery) Location ............................................................. 69
Specification ................................................. 462
Warning message ........................................ 72
Hybrid battery (traction battery) air vents ............................................................................... 71
Hybrid system .................................................. 66 Acoustic Vehicle Alerting System .......68
Emergency shut off system...................... 72
Energy monitor/consumption screen99
EV drive mode............................................. 189

521Alphabetical Index
Power control unit coolantCapacity ......................................................... 464
Checking ....................................................... 373
Preparing and checking before winter........................................................................... 291
Power easy access system ........................ 142
Power outlets ................................................ 343
Power steering (Elect ric power steering
system).......................................................... 284 Warning light ................................................. 421
Power switch .................................................. 184 Auto power off function ...........................187
Changing the power switch modes ..187
Power switch (engine switch) If your vehicle has to be stopped in an
emergency ................................................. 410
Power windows Door lock linked window operation..154
Jam protection function............................153
Operation........................................................153
Window lock switch ................................. 155
Pre-Collision System (PCS) Function .......................................................... 220
PCS OFF switch .........................................222
Warning light ............................................... 424
R
Radar cruise control (dynamic radar cruise control with full-speed range)............. 238
Radiator ........................................................... 374
RCTA Function ............................................................ 261
Warning message..................................... 262
RCTA (Rear Cross Traffic Alert) ......... 253
RCTA function ............................................. 262
Rear automatic air conditioning system ............................................................................315
Rear Cross Traffic Alert (RCTA) ........... 261
Rear door sunshades ................................. 345
Rear fog lights Switch ..............................................................206 Rear seats .........................................................132
Adjustment ..................................................... 133
Folding down the rear seatbacks ....... 133
Head restraints............................................. 145
Seat heaters ................................................... 318
Rear side marker lights Light switch .................................................. 200
Replacing light bulbs ............................... 400
Rear turn signal lights Replacing light bulbs ...................400, 404
Turn signal lever .......................................... 194
Wattage ......................................................... 468
Rear view mirror Inside rear view mirror ............................. 149
Outside rear view mirrors...................... 150
Rear window defogger ............................. 306
Rear window wiper.......................................210
Refueling Capacity ......................................................... 462
Fuel types ....................................................... 462
If the fuel filler do or cannot be opened
..........................................................................446
Opening the fuel tank cap ....................... 211
Regenerative braking ....................................67
Remote Touch .............................................. 298
Replacing Electronic key battery ..............................393
Fuses................................................................ 395
Light bulbs .................................................... 399
Tires .................................................................. 432
Resetting the message indicating mainte- nance is required ...................................... 362
Rev indicator .................................................... 85
Rev peak............................................................. 85
Road Sign Assist .......................................... 236
RSA (Road Sign Assist) ............................ 236
S
Seat belt reminder light....................421, 422
Seat belts............................................................ 26 Automatic Locking Retractor................. 28
Child restraint system installation ......... 46