
5687-2. Steps to take in an emergency
RX450h_U_OM0E013U
If you have a set of jumper (or booster) cables and a second vehicle with a 12-volt
battery, you can jump start your vehicle by following the steps below.
Confirm that the electronic key is
being carried.
When connecting the jumper (or
booster) cables, depe nding on the situa-
tion, the alarm may activate and doors
locked. (
P. 88)
Open the hood ( P. 473) and fuse
box cover.
Open the exclusive jump starting
terminal cover.
If the 12-volt battery is discharged
The following procedures may be used to start the hybrid system if the vehi-
cle’s 12-volt battery is discharged.
You can also call your Lexus deal er or a qualified repair shop.
1
2
3

5707-2. Steps to take in an emergency
RX450h_U_OM0E013U
Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximatel y 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
Open and close any of the doors of your vehicle with the power switch off.
Maintain the engine speed of the seco nd vehicle and start the hybrid system
of your vehicle by turning th e power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator light does not
come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Close the exclusive jump starting termin al cover, and reinstall the fuse box
cover to its original position.
Once the hybrid system starts, have th e vehicle inspected at your Lexus dealer
as soon as possible.
■Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the hybrid system is off.
●Turn off any unnecessary electrical components when the vehicle is running at a low
speed for an extended period , such as in heavy traffic.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery w ill discharge gradually even when the vehicle
is not in use, due to natural discharge and the draining effects of certain electrical appli-
ances. If the vehicle is left for a long time, the 12-volt battery may discharge, and the
hybrid system may be unable to start. (The 12-volt battery recharges automatically while
the hybrid system is operating.)
■When the 12-volt battery is removed or discharged
●In some cases, it may not be possible to un lock the doors using the smart access system
with push-button start when the 12-volt battery is discharged. Use the wireless remote
control or the mechanical key to lock or unlock the doors.
●The hybrid system may not start on the first attempt after the 12-volt battery has
recharged but will start normally after the second attempt. This is not a malfunction.
●The power switch mode is memorized by the vehicle. When the 12-volt battery is
reconnected, the system will retu rn to the mode it was in before the 12-volt battery was
discharged. Before disconnect ing the 12-volt battery, turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt battery dis-
charged, be especially careful when reconnecting the 12-volt battery.
●The power back door must be initialized. ( P. 150)
6
7
8
9
10
11

636
RX450h_U_OM0E013UWhat to do if... (Troubleshooting)
What to do if... (Troubleshooting)
●If you lose your mechanical keys, ne
w genuine mechanical keys can be made
by your Lexus dealer. ( P. 133)
●If you lose your electronic keys, the risk of vehicle theft increases significantly.
Contact your Lexus dealer immediately. ( P. 135)
●Is the electronic key battery weak or depleted? ( P. 506)
●Is the power switch in ON mode?
When locking the doors, turn the power switch off. (P. 233)
●Is the electronic key left inside the vehicle?
When locking the doors, make sure that you have the electronic key on your
person.
●The function may not operate properly du e to the condition of the radio wave.
( P. 160)
●Is the child-protector lock set?
The rear door cannot be opened from in side the vehicle when the lock is set.
Open the rear door from outside and then unlock the child-protector lock.
( P. 139)
If you have a problem, check the foll owing before contacting your Lexus
dealer.
The doors cannot be locked, unlocked, opened or closed
You lose your keys
The doors cannot be locked or unlocked
The rear door cannot be opened

637What to do if... (Troubleshooting)
RX450h_U_OM0E013U
●Did you press the power switch while firmly depressing the brake pedal? \
(P. 232)
●Is the shift lever in P? ( P. 234)
●Is the electronic key anywhere detectable inside the vehicle? ( P. 158)
●Is the steering wheel unlocked? ( P. 235)
●Is the electronic key battery weak or depleted?
In this case, the hybrid system can be started in a temporary way. ( P. 566)
●Is the 12-volt battery discharged? ( P. 568)
●Is the power switch in ON mode?
If you cannot release the shift lever by depressing the brake pedal with the
power switch in ON mode ( P. 563)
●It is locked automatically to prevent theft of the vehicle. ( P. 235)
●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. 189)
●The auto power off function will be operated if the vehicle is left in
ACCESSORY or ON mode (the hybrid sy stem is not operating) for a period
of time. ( P. 234)
If you think something is wrong
The hybrid system does not start
The shift lever cannot be shifted from P even if you depress the brake
pedal
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

642Alphabetical index
RX450h_U_OM0E013U
CareAluminum wheels ............................. 459
Exterior................................................... 458
Interior .....................................................462
Seat belts ................................................463
Self-restoring coat ............................ 458
Cargo capacity............................ 212, 582
Cargo hooks ...........................................427
Cargo net hooks ....................................427
Chains .........................................................391
Child restraint system............................ 59 Booster seats installation...................68
Convertible seats installation ..............................................66
Front passenger occupant classification system ...........................51
Infant seats definition ...........................65
Infant seats installation ..........................61
Installing CRS with LATCH anchors ..................................................... 71
Installing CRS with seat belts ..........................................................65
Installing CRS with top tether strap.......................................................... 74
LATCH anchors ..................................... 71 Child safety
.................................................... 58
12-volt battery precautions ...........................485, 572
Airbag precautions................................ 41
Child restraint system......................... 59
How your child should wear the seat belt .............................. 34
Installing child restraints .................... 59
Moon roof precautions ....................196
Panoramic moon roof precautions .......................................200
Power back door precautions ......................................... 152
Power window lock switch............ 189
Power window precautions ........... 192
Rear door child-p rotectors ............139
Removed key battery precautions ....................................... 507
Seat belt extender precautions .......................................... 36
Seat belt precautions .......................... 36
Seat heater precautions ................... 414
Child-protectors .................................... 139
Cleaning ....................................... 458, 462 Aluminum wheels .............................. 459
Exterior ...................................................458
Interior ..................................................... 462
Seat belts................................................ 463
Clock................................................. 97, 433
Coat hooks ..............................................444
Condenser.............................................. 480
Console box ............................................422
Consumption screen .................. 106, 124
C

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

648Alphabetical index
RX450h_U_OM0E013U
Keyless entrySmart access system with push-button start ............................. 158
Wireless remote control ....... 136, 142
Keys..............................................................132 Battery-saving function .................... 160
Electronic key ........................................132
Engine switch ....................................... 232
If the electronic key does not operate properly............................ 564
If you lose your keys ................ 133, 135
Key number plate ................................132
Keyless entry ..........................................132
Mechanical key .................................... 133
Power switch........................................ 232
Replacing the battery ...................... 506
Warning buzzer ...................................137
Wireless remote control ..................132
Knee airbags ............................................. 38 Lane Departure Alert
with steering control (LDA) ......... 302
Lane-Keeping Assist (LKA) .............292
Language (multi-information display) ..................................................... 113
LATCH anchors ........................................ 71
LDA (Lane Departure Alert with steering control) ...................... 302
Lever Auxiliary catch lever ......................... 473
Hood lock release lever................. 473
Shift lever ............................................... 239
Turn signal lever ................................. 244
Wiper lever...............................260, 265
Lexus Climate Concierge................ 404
Lexus Enform
*
Lexus Enform Remote*
LEXUS Enform Safety Connect.................................................452
Lexus parking assist monitor ............347 Display.....................................................348
Precautions ........................................... 354
Lexus Safety System+ .......................... 271 Automatic High Beam.................... 255
Dynamic radar cruise control ..... 323
Dynamic radar cruise control with full-speed range .................... 311
LDA (Lane Departure Alert with steering control) ................. 302
LKA (Lane-Keeping Assist) ........292
PCS (Pre-Collision System) ....... 279
KL

652Alphabetical index
RX450h_U_OM0E013U
Radar cruise control (dynamic radar cruise control) ........................ 323
Radar cruise control (dynamic radar cruise control
with full-speed range) ........................ 311
Radiator ....................................................480
Rear Cross Traffic Alert .................... 363
Rear door sunshades .......................... 443
Rear seat Folding down the rear seatbacks ............................................. 165
Rear seat heaters....................................416
Rear side marker lights Light switch ............................................ 251
Replacing light bulbs ......................... 513
Rear turn signal lights Replacing light bulbs ......................... 513
Turn signal lever ................................. 244
Wattage ................................................. 590
Rear view mirror Inside rear view mirror ..................... 183
Outside rear view mirrors .............. 185
Rear window defogger ...................... 409
Rear window wiper.............................. 265 Refueling................................................... 267
Capacity.................................................584
Fuel types...............................................584
Opening the fuel tank cap ............ 267
When the fuel filler door cannot be opened ......................... 269
Regenerative braking.............................78
Remote Touch
*.................................... 398
Replacing Electronic key battery .................... 506
Fuses ....................................................... 508
Light bulbs...............................................513
Tires .......................................................... 549
Windshield wiper inserts ...............504
Reporting safety defects for U.S. owners ...................................622
Resetting the message indicating maintenance is required .................466
Rev indicator ..............................................99
Rev peak ......................................................99
Road accident cautions ........................ 83
R