
5597-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
WARNING
■When using the compact spare tire
●Remember that the compact spare tire provided is specifically designed for use with
your vehicle. Do not use your compact spare tire on another vehicle.
●Do not use more than one compact spare tire simultaneously.
●Replace the compact spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking.
■When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may not
operate correctly:
Also, not only can the following system not be utilized fully, but it may even negatively
affect the drive-train components:
• E-Four (AWD models)
■Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact spare tire is
installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to observe
this precaution may lead to an accident causing death or serious injury.
■After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their storage
location to reduce the possibility of personal injury during a collision or sudden brak-
ing.
• ABS & Brake assist
• VSC
• TRAC
• EPS
• Trailer Sway Control
• VDIM
• Adaptive Variable Suspension System (if equipped)
• Cruise control (if equipped)
• Dynamic radar cruise control (if equipped)
• Dynamic radar cruise control with full- speed range (if equipped)
• PCS (Pre-Collision System) (if equipped)
• LDA (Lane Departure Alert with
steering control) (if equippedF
• LKA (Lane-Keeping Assist) (if
equipped)
• Automatic High Beam (if equipped)
• AFS (Adaptive Front-lighting System) (if equipped)
• Tire pressure warning system
• Intuitive parking assist
• Lexus parking assist monitor (if equipped)
• Panoramic view monitor (if equipped)
• BSM (Blind Spot Monitor)
• Navigation system

5627-2. Steps to take in an emergency
RX450h_U_OM0E013U
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. (P. 568)
●One or both of the 12-volt battery terminals may be disconnected. ( P. 483)
Contact your Lexus dealer if the problem cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start, the following steps can be used as an
interim measure to start the hybrid system if the power switch is functioning nor-
mally.
Do not use this starting procedur e except in cases of emergency.
Turn the power switch to ON mode an d check that the parking brake is set.
( P. 233, 245)
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for ab out 15 seconds while depressing the
brake pedal firmly.
Even if the hybrid system can be starte d using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.
The interior lights and headlights do not turn on, or the horn does not
sound.
Emergency start function
1
2
3
4

638What to do if... (Troubleshooting)
RX450h_U_OM0E013U
●The seat belt reminder light is flashing
Are the driver and the front passe nger wearing the seat belts? (P. 538)
●The parking brake indicator is on
Is the parking brake released? ( P. 245)
Depending on the situation, other types of warning buzzer may also sound.
( P. 536, 543)
●Did anyone inside the vehicle open a door during setting the alarm?
The sensor detects it and the alarm sounds. ( P. 87)
Do one of the following to stop the alarms:
• Unlock the doors.
• Turn the power switch to ACCESSORY or ON mode, or start the hybrid system.
●Is the message displayed on the multi-information display?
Check the message on the multi-information display. ( P. 543)
●When a warning light turns on or a warning message is displayed, refer to
P. 536, 543.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

640
RX450h_U_OM0E013UAlphabetical index
Alphabetical index
A/C ............................................................ 405
Air conditioning filter......................... 501
Automatic air conditioning system ................................................. 405
ABS (Anti-lock Brake System)........ 381 Warning light .......................................537
Adaptive Front-lighting System (AFS) ...................................................... 252
Adaptive Variable Suspension System ................................................... 382
AFS (Adaptive Front-lighting System) .................................................. 252
Air conditioning filter ........................... 501
Air conditioning system ..................... 405 Air conditioning filter......................... 501
Automatic air conditioning system ................................................. 405
S-FLOW mode ................................. 406 Airbags ........................................................ 38
Airbag operating conditions .......... 46
Airbag precautions for your child............................................................ 41
Airbag warning light ........................536
Correct driving posture .................... 30
Curtain shield airbag operating conditions ....................... 46
Curtain shield airbag precautions .......................................... 44
Front passenger occupant classification system........................... 51
General airbag precautions ............. 41
Locations of airbags............................ 38
Modification and disposal of airbags .................................................... 45
Seat cushion airbag ............................. 38
Side airbag operating conditions ............................................. 46
Side airbag precautions ...................... 41
Side and curtain shield airbags operating conditions ....................... 46
Side and curtain shield airbags precautions ............................................ 41
SRS airbag instructions for Canadian owners ................... 624
SRS airbags ............................................. 38
Alarm ............................................................87
A

641Alphabetical index
RX450h_U_OM0E013U
Anchor brackets ........................................ 61
AntennaSmart access system with push-button start ................... 158
Anti-lock Brake System (ABS)........ 381 Warning light .......................................537
Approach warning.....................318, 330
Armrest .................................................... 443
Assist grips .............................................. 444
Audio system
*
Automatic air conditioning system .................................................... 405 Air conditioning filter......................... 501
Automatic air conditioning system ................................................. 405
S-FLOW mode ............................... 406
Automatic headlight leveling system .................................................... 253
Automatic High Beam ....................... 255
Automatic light control system.........251
Auxiliary boxes ...........................426, 430
Back door Power back door .................................142
Touchless power back door ......... 144
Wireless remote control ..................142
Back-up lights Replacing light bulbs ......................... 513
Wattage ................................................. 590 Battery (12-volt battery)
Battery checking ................................483
If the 12-volt battery is discharged........................................ 568
Preparing and checking before winter....................................................390
Warning light .......................................536
Battery (traction battery) ..................... 80
Blind Spot Monitor (BSM) ............... 363 Blind Spot Monitor function ............................................367
Rear Cross Traffic Alert function ............................................. 371
Bottle holders .........................................425
Brake Brake Hold ........................................... 249
Fluid ......................................................... 588
Parking brake ...................................... 245
Regenerative braking ......................... 78
Warning light .......................................536
Brake assist ...............................................381
Brake Hold...............................................249 Warning light ....................................... 537
Break-in tips ........................................... 206
Brightness control Instrument panel light control ........ 99
BSM (Blind Spot Monitor) ............... 363 Blind Spot Monitor function......... 367
Rear Cross Traffic Alert function.................................................. 371
B
*: Refer to the “NAVIGATION SYSTEM OWNER’S MANUAL”.

644Alphabetical index
RX450h_U_OM0E013U
DrivingBreak-in tips ........................................ 206
Correct posture.....................................30
Driving mode select switch .......... 377
Hybrid vehicle driving tips.............387
Procedures ...........................................204
Winter drive tips ................................ 390
Driving position memory..................... 174 Memory recall function..................... 177
Power easy access system .............174
Dynamic radar cruise control ......... 323
Dynamic radar cruise control with full-speed range .......................... 311
E-Four ....................................................... 382
ECB (Electronically Controlled Brake System) ..................................... 381
Eco drive mode ......................................377
EDR (Event data recorder) .................... 11
Electric motor Location ..................................................... 76
Specification ........................................ 584
Electric Power Steering (EPS) ........ 381 Warning light .......................................537
Electronic key ..........................................132 Battery-saving function .................... 159
If the electronic key does not operate properly............................ 564
Replacing the battery ...................... 506 Electronically Controlled
Brake System (ECB) .........................381
Emergency flashers ............................ 528
Emergency, in case of If a warning buzzer sounds ..........536
If a warning light turns on ..............536
If a warning message is displayed ............................................ 543
If the 12-volt battery is discharged........................................ 568
If the electronic key does not operate properly ............................564
If the hybrid system will not start .................................................561
If you have a flat tire ..........................549
If you lose your keys................ 133, 135
If you think something is wrong...................................................535
If your vehicle becomes stuck...................................................... 578
If your vehicle has to be stopped in an
emergency ........................................ 529
If your vehicle needs to be towed ...................................................530
If your vehicle overheats ................ 574
Energy monitor ....................................... 124
E

645Alphabetical index
RX450h_U_OM0E013U
EngineACCESSORY 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 ................................................ 590F

651Alphabetical index
RX450h_U_OM0E013U
Paddle shift switches ................. 240, 241
Panic mode ...............................................133
Panoramic moon roof .......................... 197Jam protection function ................... 198
Operation ................................................197
Parking brake......................................... 245 Parking brake engaged warning buzzer/message.......... 247
Warning light .......................................537
Parking lights Light switch ............................................ 251
Replacing light bulbs ......................... 513
PCS (Pre-Collision System) ............ 279 Warning light ...................................... 538
Personal lights..........................................419
Power back door .................................... 142 Touchless power back door ......... 144
Wireless remote control ..................142
Power back door opener and closer ........................................................ 142 Power control unit coolant
Capacity................................................. 587
Checking ............................................... 479
Preparing and checking before winter ....................................390
Radiator ................................................. 480
Power easy access system ................. 174
Power outlets ............................... 440, 441
Power steering (Electric Power Steering system)..................................381 Warning light ....................................... 537
Power switch...........................................232
Power windows Door lock linked window operation ............................................... 191
Jam protection function................... 190
Operation............................................... 189
Window lock switch ......................... 189
Pre-Collision System (PCS)............. 279 Warning light .......................................538
P
*: Refer to the “NAVIGATION SYSTEM OWNER’S MANUAL”.