2021 LEXUS RX450h brake sensor

4257-2. Steps to take in an emergency
7
When trouble arises
■Brake hold operated indicator
■Master warning light
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound
even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■SRS warning light
This warning light system monitors the air-
bag sensor assembly, fr ont impact sensors,
side impact sensors (front door), side
impact sensors (rear), driver’s seat position
sensor, driver’s seat be lt buckle switch, front
passenger occupant cl assification system
(ECU and sensors), “AIR BAG ON” indica-
tor light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch,
driver’s seat belt pretensioner, front passen-
ger’s seat belt pretensioner and force lim-
iter, airbags, interconnecting wiring and
power sources. ( P.30)
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving
trips.
If the light does not go off even after several
trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning
light (warning buzzer)
When the 12-volt battery charge becomes
insufficient or the voltage temporarily
drops, the electric power steering system
warning light may come on and the warning
buzzer may sound.
■When the tire pressure warning light
comes on
Inspect the tires to check if a tire is punc-
tured.
If a tire is punctured:  P.432
If none of the tires are punctured:
Turn the power switch off then turn it to ON
mode. Check if the tire pressure warning
light comes on or blinks.
If the tire pressure warning light blinks for
1 minute then stays on
There may be a malfunction in the tire
pressure warning system. Have the vehicle
inspected by your Lexus dealer immedi-
ately.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
A buzzer sounds and the warning light comes on and flashes to indicate
that the master warning system has detected a malfunction.
P.428

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

511What to do if... (Troubleshooting)
If you cannot release the shift lever by
depressing the brake pedal with the power
switch in ON mode (P.192)
It is locked automatically to prevent
theft of the vehicle. ( P.185)
 Is the window lock switch pressed?
The power window except for the one at
the driver’s seat cannot be operated if the
window lock switch is pressed. ( P.155)
 The auto power off function will be
operated if the vehicle is left in
ACCESSORY or ON mode (the
hybrid system is not operating) for a
period of time. ( P.187)
 The seat belt reminder light is flash-
ing
Are the driver and the passengers wearing
the seat belts? ( P.421)
 The parking brake indicator is on
Is the parking brake released? ( P.195)
Depending on the situation, other
types of warning buzzer may also
sound. ( P.418, 428) 
Did anyone inside the vehicle open
a door during setting the alarm?
The sensor detects it and the alarm sounds.
( P.75)
Do one of the following to stop the
alarms:
 Unlock the doors.
 Turn the power switch to ACCES-
SORY or ON mode, or start the
hybrid system.
 Is the message displayed on the
multi-information display?
Check the message on the multi-informa-
tion display. ( P.428)
 When a warning light turns on or a
warning message is displayed, refer
to P.418, 428.
 Stop the vehicle in a safe place and
replace the flat tire with the spare
tire. ( P.432)
The steering wheel cannot be
turned after the hybrid system is
stopped
The windows do not open or
close by operating the power
window switches
The power switch is turned off
automatically
A warning buzzer sounds during
driving
An alarm is activated and the
horn sounds
A warning buzzer sounds when
leaving the vehicle
A warning light turns on or a
warning message is displayed
When a problem has occurred
If you have a flat tire

514Alphabetical Index
BrakeBrake hold...................................................... 198
Fluid ......................................................375, 465
Parking brake ............................................... 195
Regenerative braking ................................. 67
Warning light ................................................ 418
Brake assist .................................................... 283
Break-in tips.....................................................165
Brightness control Instrument panel light control ................ 87
BSM (Blind Spot Monitor)........................247
Buzzer Hands off steering wheel warning (LTA)......................................................................... 234
C
Care Exterior ...........................................................356
Interior .............................................................359
Seat belts........................................................359
Wheels and wheel ornaments............356
Cargo capacity..................................... 169, 172
Cargo hooks ................................................. 329
Cargo net hooks .......................................... 329
Center Display .............................................300
Chains .............................................................. 292
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 .......378, 453
Airbag precautions...................................... 36
Child restraint system................................. 46
Heated steering wheel and seat heater precautions................................................. 318 How your child should wear the seat belt
............................................................................. 27
Moon roof precautions.............................157
Panoramic moon roof precautions ... 160
Power back door precautions ............... 113
Power window lock switch .................... 155
Power window precautions .................. 154
Rear door child-protectors ..................... 112
Seat belt extender precautions.............. 27
Seat belt precautions .................................. 45
Child-protectors............................................. 112
Cleaning Exterior........................................................... 356
Interior ............................................................ 359
Radar sensor ..................................................214
Seat belts ....................................................... 359
Wheels and wheel ornaments ........... 356
Clock ........................................................83, 343
Coat hooks..................................................... 343
Coin box.......................................................... 328
Compass ......................................................... 352
Condenser ..................................................... 374
Console box .................................................. 326
Cooling system............................................. 373 Engine overheating...................................454
Hybrid system overheating ................. 456
Cornering lights ........................................... 202 Replacing light bulbs ............................... 400
Cruise control Dynamic radar cruise control with full-speed range ......................................238
Cup holders ................................................... 327
Current fuel consumption .......................... 90
Curtain shield airbags .................................. 30
Customizable features ..............................480
D
Daytime running light system .................200
Defogger Outside rear view mirrors.................... 306
Rear window ............................................... 306
Windshield ................................................... 306

520Alphabetical Index
Dynamic radar cruise control with full-speed range ...................................... 238
Energy monitor............................................ 100
G-force................................................................ 91
LTA (Lane Tracing Assist).................... 232
Menu icons ...................................................... 89
Meter control switches .............................. 89
Navigation system-linked display ........ 92
Pop-up display...............................................88
Settings .............................................................. 92
Suggestion function..................................... 93
Tire pressure ................................................ 382
Units ...................................................................... 91
Warning message..................................... 428
N
Navigation system-linked display....92, 98
Noise from under vehicle ...............................6
O
“ODO TRIP” switch ...................................... 87
Odometer ......................................................... 87
Odometer and trip meter display Display items ................................................... 87
“ODO TRIP” switch .................................... 87
Pop-up display............................................... 87
Oil Engine oil ....................................................... 463
Rear differential oil ....................................465
Opener Fuel filler door..................................................211
Hood................................................................369
Outer foot lights Location............................................................ 321
Outside door handle lights........................321
Outside rear view mirrors Adjustment..................................................... 150
BSM (Blind Sport Monitor) ................. 247
Folding ............................................................... 151
Linked mirror functi on when reversing
.......................................................................... 150 Mirror position memory ...........................142
Outside rear view mirror defoggers306
RCTA function ..............................................261
Outside temperature.................................... 83
Overheating .................................................. 454
P
Paddle shift switches ..........................192, 193
Panic mode ......................................................107
Panoramic moon roof Jam protection function ........................... 159
Operation ....................................................... 158
Parking assist sensors (intuitive parking assist) ............................................................. 255
Parking brake Operation ....................................................... 195
Parking brake engaged warning buzzer............................................................................197
Warning light ............................................... 424
Warning message .......................................197
Parking lights Light switch .................................................. 200
Replacing light bulbs ............................... 400
Parking Support Brake function (for rear-crossing vehicles) ...........................277Function .......................................................... 277
Parking Support Brake function (static objects) ........................................................... 271Function ............................................................ 271
PCS (Pre-Collision System) Function ..........................................................220
PCS OFF switch ........................................ 222
Warning light ............................................... 424
Personal lights.................................................321
PKSA (Parking Support Alert) .............. 253
PKSB (Parking Support Brake)............. 266 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

522Alphabetical Index
Cleaning and maintaining the seat belt.........................................................................359
Emergency Locking Retractor .............. 28
How to wear your seat belt ......................27
How your child should wear the seat belt .............................................................................27
Pregnant women, proper seat belt use ............................................................................ 26
Reminder light and buzzer ......... 421, 422
Seat belt extender .........................................27
Seat belt pretensioners .............................. 29
SRS warning light ...................................... 420
Seat heaters .................................................... 318
Seat position memory.................................. 142
Seat ventilators .............................................. 318
Seating capacity............................................. 172
Seats Adjustment............................................. 131, 133
Adjustment precautions .................. 131, 132
Child seats/child restraint system installa-tion .................................................................... 45
Cleaning.........................................................359
Driving position memory......................... 142
Folding down the rear seatbacks........133
Head restraints .............................................145
Power easy access system ..................... 142
Properly sitting in the seat ........................ 25
Seat heaters ................................................... 318
Seat position memory ............................... 142
Seat ventilators............................................. 318
Sensor Automatic headlight system.................200
Automatic High Beam system............ 203
Inside rear view mirror..............................149
Intuitive parking assist.............................. 255
LTA (Lane Tracing Assist).....................227
Parking Support Brake function (rear-crossing vehicles).......................277
Parking Support Brake function (static objects).........................................................272
Radar sensor...................................... 214, 249
Rain-sensing windshield wipers......... 207 RCTA............................................................... 262
Service plug ...................................................... 69
Service reminder message ..................... 362
Shift lever Hybrid transmission..................................... 191
Shift lever light ................................................321
Side airbags ...................................................... 30
Side doors........................................................ 109
Side marker lights Light switch .................................................. 200
Replacing light bulbs ............................... 400
Side mirrors Adjustment ..................................................... 150
BSM (Blind Sport Monitor).................. 247
Folding................................................................ 151
Linked mirror functi on when reversing
........................................................................... 150
Mirror position memory ...........................142
RCTA function ..............................................261
Side turn signal lights Replacing light bulbs ............................... 400
Turn signal lever .......................................... 194
Side windows ..................................................153
Smart access system with push-button startAntenna location ......................................... 125
Entry functions ..................................... 109, 114
Starting the hybrid system ...................... 184
Smartphone holder..................................... 326
Snow tires .........................................................291
Spare tire......................................................... 432 Storage location .........................................433
Spark plug ...................................................... 464
Specifications ................................................ 460
Speedometer ................................................... 83
Steering lock Column lock release ................................. 185
Steering lock system warning message........................................................................... 185
Steering wheel Adjustment ..................................................... 148
Heated steering wheel ............................. 318