key battery Lexus IS350 2021 / LEXUS 2021 IS 300, IS 350 (OM53E98U) Owner's Guide

3487-2. Steps to take in an emergency
Check the engine oil and change it if neces-
sary. After changing the engine oil, make
sure to reset the message. ( P.298)
■If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed.
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the
engine oil, make sure to reset the message.
(  P.298)
■If a message that in dicates the need for
visiting your Lexus dealer is displayed
The system or part shown on the
multi-information display is malfunctioning.
Have the vehicle inspected by your Lexus
dealer immediately.
■If a message that in dicates the need for
referring to Owner’s Manual is dis-
played
●If any of the following messages are
shown on the multi-information display,
follow the instructions.
• “Engine Coolant Temp High” ( P.365)
• “High Transmission Fluid Temp” ( P.138)
●If any of the following messages are
shown on the multi-information display, it
may indicate a malfunction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Access System with Elec. Key Malfunc-
tion”
●If any of the following messages are
shown on the multi-information display, it
may indicate a malfunction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Braking Power Low”
• “Charging System Malfunction”
• “Oil Pressure Low”
NOTICE
■If “High Power Consumption Power
to Climate Temporarily Limited” is
displayed frequently
There is a possible malfunction relating
to the charging system or the battery
may be deteriorating. Have the vehicle
inspected by your Lexus dealer.

3577-2. Steps to take in an emergency
7
When trouble arises
One of the following may be the cause
of the problem:
There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle.
 The engine may be flooded.
Try to restart the engine again fol-
lowing correct starting procedures.
( P.134)
 There may be a malfunction in the
engine immobilizer system.
( P.60)
One of the following may be the cause
of the problem:
 The battery may be discharged.
( P.361)
 The battery terminal connections
may be loose or corroded.
( P.301) The engine starting system may be
malfunctioning due to an electrical
problem such as electronic key battery
depletion or a blown fuse. However, an
interim measure is available to start the
engine. (
P.357)
One of the following may be the cause
of the problem:
 One or both of the battery terminals
may be disconnected. ( P.301)
 The battery may be discharged.
( P.361)
 There may be a malfunction in the
steering lock system.
Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the engine does not start, the
following steps can be used as an
interim measure to start the engine if
the engine switch is functioning nor-
mally:
1 Push the parking brake switch to
check that the parking brake is set.
(P.143)
Parking brake indicator will come on.
If the engine will not start
If the engine will not start even
though correct starting procedures
are being followed ( P.134), con-
sider each of the following points:
The engine will not start even
though the starter motor oper-
ates normally.
The starter motor turns over
slowly, the interior lights and
headlights are dim, or the horn
does not sound or sounds at a low
volume.
The starter motor does not turn
over
The starter motor does not turn
over, the interior lights and head-
lights do not turn on, or the horn
does not sound.
Starting the engine in an emer-
gency

3597-2. Steps to take in an emergency
7
When trouble arises
Remove the cover inside the trunk and
pull the lever.
■When the electronic key does not work
properly
●Make sure that the smart access system
with push-button start has not been deac-
tivated in the customization setting. If it is
off, turn the function on.
●Check if battery-saving mo de is set. If it is
set, cancel the function. ( P.100)
■Doors
Use the mechanical key ( P.90) in
order to perform th e following opera-
tions:
If the fuel filler door cannot
be opened
If the fuel filler door cannot be
opened by pressing the center of
the rear edge of the fuel filler door
with the doors unlocked, the follow-
ing procedure can be used to open
the fuel filler door.
Opening the fuel filler door
If the electronic key does not
operate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.100) 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 and trunk can be opened and
the engine can be started by follow-
ing 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, unlocking the trunk

3617-2. Steps to take in an emergency
7
When trouble arises
be started, contact your Lexus dealer.
■Stopping the engine
Shift the shift lever to P and press the engine
switch as you normally do when stopping
the engine.
■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.316)
■Changing engine switch modes
Release the brake pedal and press the
engine switch in step 3 above. The engine
does not start and modes will be changed
each time the switch is pressed. ( P.136)
If the vehicle battery is dis-
charged
The following procedures may be
used to start the engine if the vehi-
cle’s battery is discharged.
You can also call your Lexus dealer
or a qualified repair shop.

3627-2. 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.63)
2 Open the hood. ( P.293)
3 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,
connect a negative cable clamp to on the second vehicle and connect the
clamp at the other end of the negative cable to .
IS350 AWD/IS350/IS300 AWD
Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic poin t away from the battery and any mov-
ing parts as shown in the illustration
Restarting the engine
A
B
C
D
A
B
C
D

3637-2. Steps to take in an emergency
7
When trouble arises
IS300Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic poin t away from the battery and any mov-
ing parts as shown in the illustration
4 Start the engine of the second vehi-
cle. Increase the engine speed
slightly and maintain at that level for
approximately 5 minutes to
recharge the battery of your vehi-
cle.
5 Open and close any of the doors of
your vehicle with the engine switch
off.
6 Maintain the engine speed of the
second vehicle and start the engine
of your vehicle by turning the
engine switch to IGNITION ON
mode.
7 Once the vehicle’s engine has
started, remove the jumper cables
in the exact reverse order from
which they were connected.
Once the engine starts, have the vehi-
cle inspected at your Lexus dealer as
soon as possible.
■Starting the engine when the battery is
discharged
The engine cannot be started by push-start-
ing.
■To prevent battery discharge
●Turn off the headlights and the audio sys-
tem while the engine is off.
●Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■Charging the battery
The electricity stored in the battery will dis-
charge 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 battery may discharge, and the engine
may be unable to start. (The battery
recharges automatically during driving.)
■When recharging or replacing the bat-
tery
●In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
battery is discharged. Use the wireless
remote control or the mechanical key to
lock or unlock the doors.
A
B
C
D

418What 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.358)
 If you lose your electronic keys, the
risk of vehicle theft increases signifi-
cantly. Contact your Lexus dealer
immediately. ( P.358)
 Is the electronic key battery weak or
depleted? ( P.316)
 Is the engine switch in IGNITION
ON mode?
When locking the doors, turn the engine
switch off. ( P.136)
 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.100)
 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.94)
 The function to prevent the elec-
tronic key from being left inside the
trunk will operate and you can open
the trunk as usual. Take the key out
from the trunk. ( P.97)
 Did you press the engine switch
while firmly depressing the brake
pedal? ( P.134)
 Is the shift lever in P? ( P.134)
 Is the electronic key anywhere
detectable inside the vehicle?
( P.99)
 Is the steering wheel unlocked?
( P.134)
 Is the electronic key battery weak or
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
The trunk lid is closed with the
electronic key left inside
If you think something is wrong
The engine does not start

419What to do if... (Troubleshooting)
depleted?
In this case, the engine can be started in a
temporary way. (P.360)
Is the battery discharged? ( P.361)
 Is the engine switch in IGNITION
ON mode?
If you cannot release the shift lever by
depressing the brake pedal with the engine
switch in IGNITION ON mode. ( P.139)
 It is locked automatically to prevent
theft of the vehicle. ( P.134)
 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.119)
 The auto power off function will be
operated if the vehicle is left in
ACCESSORY or IGNITION ON
mode (the engine is not running) for
a period of time. ( P.136) 
The seat belt reminder light is flash-
ing
Are the driver and the front passenger
wearing the seat belts? ( P.340)
 The parking brake indicator is on
Is the parking brake released? ( P.143)
Depending on the situation, other
types of warning buzzer may also
sound. ( P.337, 346)
 Did anyone inside the vehicle open
a door during setting the alarm?
The sensor detects it and the alarm sounds.
( P.62)
Do one of the following to deactivate
or stop the alarm:
 Unlock the doors.
 Open the trunk.
 Turn the engine switch to ACCES-
SORY or IGNITION ON mode, or
start the engine. (The alarm will be
deactivated or stopped after a few
seconds.)
 Is the electronic key left inside the
vehicle or the moon roof opened?
Check the message on the multi-informa-
tion display. ( P.346)
The shift lever cannot be shifted
from P even if you depress the
brake pedal
The steering wheel cannot be
turned after the engine is
stopped
The windows do not open or
close by operating the power
window switches
The engine 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

422Alphabetical Index
BuzzerHands off steering wheel warning (LTA).......................................................................... 188
C
Card key ............................................................ 88
Care Exterior ...........................................................280
Interior ............................................................. 283
Seat belts........................................................ 283
Wheels and wheel ornaments............280
Cargo capacity...............................................132
Cargo net ....................................................... 268
Center Display ............................................. 250
Chains .............................................................. 244
Child restraint system Fixed with a LATCH system .................. 49
Fixed with a seat belt................................... 45
Front passenger occupant classification system ............................................................. 36
Points to remember ...................................... 41
Riding with children ....................................... 41
Types of child restraint system installation method ............................................................42
Using an anchor bracket ............................ 51
Child safety Airbag precautions...................................... 33
Battery precautions .................................. 364
Child restraint system..................................42
Heated steering wheel and seat heater precautions.................................................. 261
How your child should wear the seat belt ............................................................................ 25
Moon roof precautions ............................ 122
Power window lock switch...................... 119
Power window precautions .................... 119
Rear door child-protectors ..................... 94
Removed electronic key battery precau- tions ................................................................. 317
Seat belt extender precautions ............. 25
Seat belt precautions .................................... 41
Trunk precautions ........................................ 96 Child-protectors............................................. 94
Cleaning
Exterior........................................................... 280
Interior .............................................................283
Radar sensor ................................................. 164
Seat belts ........................................................283
Wheels and wheel ornaments ........... 280
Clock ..................................................71, 72, 270
Coat hooks..................................................... 270
Condenser .....................................................300
Console box ...................................................267
Consumption screen .................................... 83
Cooling system............................................. 298 Engine overheating.................................. 365
Cruise control Dynamic radar cruise control with full-speed range ........................................192
Cup holders ....................................................267
Current fuel consumption ...........................79
Curtain shield airbags .................................. 28
Customizable features .............................. 394
D
Daytime running light system ...................149
Defogger Outside rear view mirrors.....................255
Rear window ................................................255
Windshield ....................................................255
Differential Front differential oil............. ....................... 377
Rear differential oil......... ..................... ....... 377
Dimensions .................................................... 372
Dinghy towing.................................................133
Display Center Display ........................................... 250
Dynamic radar cruise control with full-speed range ........................................192
Intuitive parking assist ............................... 210
LTA (Lane Tracing Assist) ..................... 185
Multi-information display .......................... 76
RCTA.................................................................216
Warning message .....................................346

423Alphabetical Index
Distance until next engine oil change .....75
Do-it-yourself maintenance .................... 287
Door courtesy lights ................................... 263Wattage........................................................... 381
Door lock Doors.................................................................. 92
Smart access system with push-button start ................................................................... 99
Wireless remote control........................... 90
Doors Automatic door lock ing and unlocking
system ............................................................. 95
Door glasses ................................................... 118
Door lock.......................................................... 92
Open door warning buzzer .......... 93, 94
Outside rear view mirrors ....................... 116
Rear door child-protectors ..................... 94
Drive distance ...................................................79
Drive info 1/Drive info 2/Drive info 3.....79
Driver’s seat position memory Driving position memory........................ 108
Memory recall function ........................... 109
Power easy access system .................... 108
Drive-Start Control (DSC) Sudden start restraint control................ 129
Driving Break-in tips ...................................................125
Correct driving posture .............................23
Driving mode select switch .................. 236
Procedures ..................................................... 124
Winter drive tips......................................... 243
Driving information display ........................ 78
Driving position memory........................... 108 Memory recall function ........................... 109
Power easy access system .................... 108
Driving range ....................................................79
Driving support system information display ...............................................................................81
DSC (Drive-Start Control) Sudden start restraint control................ 129 Dynamic radar cruise control with
full-speed range ..........................................192Warning message .................................... 200
E
Eco Driving Indicator.................................... 80
Eco Driving Indicator Light ........................ 80
EDR (Event data recorder) ............................7
Elapsed time ......................................................79
Electric Power Steering (EPS) .............. 238 Warning light .............................................. 340
Electronic key .................................................. 88 Battery-saving function............................100
If the electronic key does not operate properly ...................................................... 359
Replacing the battery ................................ 316
Emergency flashers .................................... 328
Emergency, in case of If a warning buzzer sounds................... 337
If a warning light turns on....................... 337
If a warning message is displayed .....346
If the battery is discharged ..................... 361
If the electronic key does not operate properly ...................................................... 359
If the engine will not start........................357
If the fuel filler do or cannot be opened
......................................................................... 359
If the vehicle is trapped in rising water ..........................................................................329
If you have a flat tire ..................................349
If you lose your keys ................................ 358
If you think something is wrong..........335
If your vehicle becomes stuck ............ 368
If your vehicle has to be stopped in an emergency .................................................328
If your vehicle needs to be towed ...... 331
If your vehicle overheats ....................... 365
Engine ACCESSORY mode............................... 136
Compartment..............................................295
Engine switch .................................................134
Fuel pump shut off system.....................336