key battery LEXUS RX450h 2021 Owner's Manual

4477-2. Steps to take in an emergency
7
When trouble arises
fuel tank. Therefore, fill the fuel tank
carefully and slowly.
RX450hL
 If the fuel filler door opener switch
cannot be operated, contact your
Lexus dealer to service the vehicle.
In case where refueling is urgently
necessary, remove the cover inside
the luggage compartment using a
tool, such as a flathead screwdriver,
and pull the lever to open the fuel
filler door.
When using a screwdri ver, make sure to
wrap its tip with tape to protect the cover.
 Using the lever to open the fuel filler
door may not allow for an adequate
reduction in fuel tank pressure
before refueling. To prevent fuel
from spilling out, turn the cap slowly
when removing it.
During refueling, fuel may spill out
from the filler opening due to air
being discharged from inside the
fuel tank. Therefore, fill the fuel tank
carefully and slowly.
■When the electronic key does not work
properly
●Make sure that the smart access system
with push-button star t has not been dis-
abled at your Lexus dealer. If it has been
disabled, re-enable it.
●Check if battery-saving mo de is set. If it is
set, cancel the function. ( P.126)
■Unlocking the door
Use the mechanical key ( P.107) in
order to perform th e following opera-
tions:
If the electronic key does not
operate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.126) or the electronic
key cannot be used because the
battery is depleted, the smart
access system with push-button
start and wireless remote control
cannot be used. In such cases, the
doors can be opened and the hybrid
system can be started by following
the procedure below.
NOTICE
■In case of a smart access system with
push-button start malfunction or
other key-rela ted problems
Take your vehicle with all the electronic
keys provided with your vehicle to your
Lexus dealer.
Locking and unlocking the doors

4497-2. Steps to take in an emergency
7
When trouble arises
When the smart access system with
push-button start is deactivated in custom-
ization setting, the powe r switch will turn to
ACCESSORY mode.
3 Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4 Press the power switch shortly and
firmly.
In the event that the hybrid system still
cannot be started, contact your Lexus
dealer.
■Stopping the hybrid system
Shift the shift lever to P, set the parking
brake, and press the power switch as you
normally do when stopping the hybrid sys-
tem.
■Replacing the key battery
As the above procedure is a temporary
measure, it is recomme nded that the elec-
tronic key battery be replaced immediately
when the battery is depleted. ( P.393)
■Alarm (For Canada)
Using the mechanical key to lock the doors
will not set the alarm system.
If a door is unlocked using the mechanical
key when the alarm system is set, the alarm
may be triggered. ( P.75)
■Changing power switch modes
Release the brake pedal and press the
power switch in step 3 above. The hybrid
system does not start and modes will be
changed each time the switch is pressed.
(  P.187)
If the 12-volt battery is dis-
charged
The following procedures may be
used to start the hybrid system if the
vehicle’s 12-volt battery is dis-
charged.
You can also call your Lexus dealer
or a qualified repair shop.

4507-2. Steps to take in an emergency
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.
1Confirm that the electronic key is
being carried.
When connecting the jumper (or booster)
cables, depending on the situation, the
alarm may activate and doors locked.
( P.76)
2 Open the hood ( P.369) and fuse
box cover. 3
Open the exclusive jump starting
terminal cover.
4 Remove the engine cover.
5 Connect a positive jumper cable clamp to on your vehicle and connect the
clamp on the other end of the positive cab le to on the second vehicle. Then,
Restarting the hybrid system
A
B

4527-2. Steps to take in an emergency
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■When removing the 12-volt battery ter-
minals
When the 12-volt battery terminals are
removed, the information stored in the
ECU is cleared. Before removing the
12-volt battery terminals, contact your
Lexus dealer.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradually even when the
vehicle is not in use, due to natural dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, 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
unlock 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 mechani-
cal 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 return to the
mode it was in before the 12-volt battery
was discharged. Before disconnecting
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
discharged, be especially careful when
reconnecting the 12-volt battery.
●The power back door mu st be initialized.
(  P.119)
■When replacing the 12-volt battery
●RX450h: Use a Central Degassing type
12-volt battery (European Regulations). RX450hL: Use a 12-volt battery
designed for this vehicle.
●RX450h: Use a 12-volt battery that the
case size is same
as the previous one
(LN2), 20 hour rate capacity (20HR) is
equivalent (60Ah) or greater, and per-
formance rating (CCA) is equivalent
(460A) or greater.
• If the sizes differ, the 12-volt battery can- not be properly secured.
• If the 20 hour rate capacity is low, even if
the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and the hybrid system
may not be able to start.
●Use a 12-volt battery with a handle. If a
12-volt battery without a handle is used,
removal is more difficult.
●After replacing, firm ly attach the follow-
ing items to the exhaust hole of the
12-volt battery.
• Use the exhaust hose that was attached to the 12-volt battery before replacing
and confirm that it is firmly connected to
the hole section of the vehicle.
• Use the exhaust hole plug included with the 12-volt battery re placed or the one
installed on the 12-volt battery prior to
the replacement. (Depending on the
12-volt battery to be replaced, the
exhaust hole may be plugged.)
RX450h
Exhaust hole plug
Exhaust hole
A
B

510What to do if... (Troubleshooting)
1-1.What to do if... (Troubleshooting)What to do if... (Troubleshooting)
If you lose your mechanical keys,
new genuine mechanical keys can
be made by your Lexus dealer.
( P.446)
 If you lose your electronic keys, the
risk of vehicle theft increases signifi-
cantly. Contact your Lexus dealer
immediately. ( P.446)
 Is the electronic key battery weak or
depleted? ( P.393)
 Is the power switch in ON mode?
When locking the doors, turn the power
switch off. ( P.187)
 Is the electronic key left inside the
vehicle?
When locking the doors, make sure that
you have the electronic key on your per-
son.
The function may not operate prop- erly due to the condition of the radio
wave. (
P.126)
 Is the child-protector lock set?
The rear door cannot be opened from
inside the vehicle when the lock is set.
Open the rear door from outside and then
unlock the child-protector lock. ( P.112)
 Did you press the power switch
while firmly depressing the brake
pedal? ( P.184)
 Is the shift lever in P? ( P.184)
 Is the electronic key anywhere
detectable inside the vehicle?
( P.125)
 Is the steering wheel unlocked?
( P.185)
 Is the electronic key battery weak or
depleted?
In this case, the hy brid system can be
started in a temporary way. ( P.448)
 Is the 12-volt battery discharged?
( P.449)
 Is the power switch in ON mode?
If you have a problem, check the
following before contacting your
Lexus dealer.
The doors cannot be locked,
unlocked, opened or closed
You lose your keys
The electronic key does not
operate properly
The doors cannot be locked or
unlocked
The rear door cannot be opened
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

515Alphabetical Index
DifferentialRear differential oil ....................................465
Dimension ...................................................... 460
Dinghy towing................................................ 183
Display Center Display........................................... 300
Dynamic radar cruise control with full-speed range ...................................... 238
Energy monitor.............................................. 99
Head-up display ........................................... 95
Intuitive parking assist.............................. 255
LTA (Lane Tracing Assist).................... 232
Multi-information display ..........................88
RCTA ................................................................ 261
Warning message..................................... 428
Distance until next engine oil change .... 87
Do-it-yourself maintenance .................... 363
Door courtesy lights .....................................321 Wattage..........................................................468
Door lock Power back door.......................................... 113
Side doors ...................................................... 109
Smart access system with push-button start ..................................................................125
Wireless remote control..........................107
Door pockets ................................................ 328
Doors Automatic door lock ing and unlocking
system ..............................................................112
Door glasses ..................................................153
Door lock warning buzzer ...................... 110
Open door warning buzzer ....................112
Outside rear view mirrors ..................... 150
Rear door child-protectors ......................112
Side doors ...................................................... 109
Drive distance .................................................. 90
Driver’s seat position memory Driving position memory......................... 142
Memory recall function ............................143
Power easy access system ..................... 142
Drive-start control ........................................165 Driving
Break-in tips .................................................. 165
Correct driving posture ............................ 25
Driving mode select switch ................... 281
Hybrid vehicle driving tips ................... 289
Procedures .................................................... 164
Winter drive tips ...........................................291
Driving assist system information ............ 92
Driving information display ........................ 90
Driving position memory............................ 142 Memory recall function.............................143
Power easy access system .....................142
Driving range ................................................... 90
Dynamic radar cruise control with full-speed range ........................................ 238Warning message ..................................... 246
E
ECB (Electronically Controlled Brake Sys-
tem) ................................................................ 283
EDR (Event data recorder) ........................... 8
E-Four .............................................................. 284
Elapsed time ..................................................... 90
Electric motor (traction motor) ................ 66
Electric Power Steering (EPS) .............. 284 Warning light .................................................421
Electronic key ................................................ 106 Battery-saving function.............................126
If the electronic key does not operate properly ....................................................... 447
Replacing the battery ...............................393
Electronic sunshade Jam protection function ........................... 159
Operation ....................................................... 158
Electronically Controlled Brake System (ECB) ............................................................ 283
Emergency flashers ..................................... 410
Emergency, in case of If a warning buzzer sounds.................... 418
If a warning light turns on........................ 418
If a warning message is displayed .....428
If the 12-volt battery is discharged ....449

518Alphabetical Index
High voltage components ....................... 69
Hybrid system precautions ..................... 69
If the hybrid system will not start ........ 444
Overheating.................................................456
Power (ignition) switch............................ 184
Regenerative braking ................................. 67
Starting the hybrid system...................... 184
Hybrid System Indicator......................85, 99
Hybrid transmission....................................... 191 M mode ............................................................193
Paddle shift switches ....................... 192, 193
Hybrid vehicle driving tips ....................... 289
I
I/M test ............................................................ 366
Identification Engine ...............................................................461
Vehicle ............................................................460
If your vehicle has to be stopped in an
emergency ................................................... 410
Ignition switch (power switch) ................ 184 Auto power off function ...........................187
Changing the power switch modes ..187
If your vehicle has to be stopped in an
emergency ................................................. 410
Immobilizer system .........................................73
Indicators ........................................................... 80
Initialization Items to initialize ......................................... 493
Maintenance .................................... 362, 373
Power windows............................................153
Tire pressure warning system ............ 385
Inside rear view mirror ................................149
Instrument panel light control ................... 87
Interior lights....................................................321 Front interior light ........................................ 321
Rear interior light ......................................... 321
Intuitive parking assist.....................253, 255 Function .......................................................... 255
Warning message..................................... 257
J
JackPositioning a floor jack ........................... 369
Vehicle-equipped jack ...........................433
Jack handle .................................................... 433
Jam protection function Electronic sunshade .................................. 159
Moon roof ...................................................... 156
Panoramic moon roof .............................. 159
Power back door.......................................... 119
Power windows ........................................... 153
Rear seats ........................................................132
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 ....................................................... 447
If you lose your keys .................................446
Key number plate ....................................... 106
Keyless entry ....................................... 107, 125
Mechanical key ............................................ 106
Power switch................................................. 184
Replacing the battery ...............................393
Warning buzzer .......................................... 125
Wireless remote control ......................... 107
Knee airbags .................................................... 30
L
Lane Tracing Assist (LTA) Operation ...................................................... 227
Warning messages...................................235
Language (multi-information display) ... 92
LATCH anchors ............................................. 54

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