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45
1-2. Opening, closing and locking the doors and trunk
1
Before driving
IS250C/350C_U
■Pa n i c m o d e
■Electronic key battery depletion
→P. 3 8
■Security feature
→P. 4 0
■When the electronic key battery is fully depleted
→P. 4 4 9
■Conditions affecting operation
→P. 3 6
■Customization that can be configured at Lexus dealer
Settings (e.g. trunk unlocking function) can be changed.
(Customizable features →P. 5 8 6 ) When is pushed for longer than about
one second, an alarm will sound for about 60
seconds and the vehicle lights will flash to
deter any person from trying to break into or
damage your vehicle.
To stop the alarm, push any button on the
wireless remote control.
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102
1-6. Theft deterrent system
IS250C/350C_U
■When the battery is disconnected
Be sure to deactivate the alarm system.
If the battery is disconnected before deactivating the alarm system, the alarm may
be triggered when the battery is reconnected.
■Alarm-operated door lock
●When the alarm is operating, the doors are locked automatically to prevent
intruders.
●Do not leave the key inside the vehicle when the alarm is operating, and make
sure the key is not inside the vehicle when recharging or replacing the battery.
NOTICE
■To ensure the system operates correctly
Do not modify or remove the system. If modified or removed, the proper operation
of the system cannot be guaranteed.
Page 150 of 626
149
2-1. Driving procedures
2
When driving
IS250C/350C_U
■If the engine does not start
The engine immobilizer system may not have been deactivated. (→P. 9 8 )
■When the steering lock cannot be released
■When the “ENGINE START STOP” switch indicator flashes in amber
The system may be malfunctioning. Have the vehicle inspected by your Lexus
dealer immediately.
■Auto power off function
If the vehicle is left in ACCESSORY mode for more than 20 minutes with the shift
lever in P, the “ENGINE START STOP” switch will automatically turn OFF.
■Electronic key battery depletion
→P. 3 8
■When the electronic key battery is fully discharged
→P. 4 4 9
■Conditions affecting operation
→P. 3 6
■Note for the entry function
→P. 3 9 The “ENGINE START STOP” switch indica-
tor will flash in green and a message will be
shown on the multi-information display. Press
the “ENGINE START STOP” switch again
while turning the steering wheel left and right.
Page 180 of 626

179
2-3. Operating the lights and windshield wipers
2
When driving
IS250C/350C_U
■Automatic light off system
●When the headlights come on: The headlights and tail lights turn off 30 seconds
after a door is opened and closed if the “ENGINE START STOP” switch has
been switched to ACCESSORY mode or turned OFF. (The light turns off
immediately if on the key is pressed after both side doors are locked.)
●When only the tail lights come on: The tail lights turn off automatically if the
“ENGINE START STOP” switch is switched to ACCESSORY mode or turned
OFF and driver’s door is opened.
To turn the lights on again, switch to IGNITION ON mode, or turn the light switch
off once and then back to or
.
■Automatic headlight leveling system (vehicles with discharge headlights)
The level of the headlights is automatically adjusted according to the number of
passengers and the loading condition of the vehicle to ensure that the headlights do
not interfere with other road users.
■Customization that can be configured at Lexus dealer
Settings (e.g. light sensor sensitivity) can be changed.
(Customizable features →P. 5 8 6 )
NOTICE
■To prevent battery discharge
Do not leave the lights on longer than necessary when the engine is not running.
Page 396 of 626

Maintenance and care4
395
IS250C/350C_U
4-1. Maintenance and careCleaning and protecting the vehicle exterior............. 396
Cleaning and protecting the vehicle interior ............... 401
4-2. Maintenance Maintenance requirements ........................ 404
General maintenance .......... 406
Emission inspection and maintenance (I/M)
programs................................ 409 4-3. Do-it-yourself
maintenance
Do-it-yourself service precautions ............................ 410
Hood ........................................... 413
Positioning a floor jack .......... 414
Engine compartment ............ 416
Tires............................................. 431
Tire inflation pressure............ 441
Wheels ...................................... 445
Air conditioning filter ........... 447
Electronic key battery.......... 449
Checking and replacing fuses ......................................... 451
Headlight aim ......................... 466
Light bulbs................................ 468
Page 450 of 626
449
4-3. Do-it-yourself maintenance
4
Maintenance and care
IS250C/350C_U
Electronic key battery
Replace the battery with a new one if it is discharged.
■You will need th e following items:
● Flathead screwdriver
● Small Phillips-head screwdriver
● Lithium battery (CR1632)
■ Replacing the battery
Take out the mechanical key.
Remove the cover.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.
STEP1
STEP2
STEP3
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450
4-3. Do-it-yourself maintenance
IS250C/350C_U
■If the electronic key battery is discharged
The following symptoms may occur.
●The smart access system with push-button start and wireless remote control will
not function properly.
●The operational range is reduced.
■Use a CR1632 lithium battery
●Batteries can be purchased at your Lexus dealer, jewelers, or camera stores.
●Replace only with the same or equivalent type recommended by a Lexus dealer.
●Dispose of used batteries according to the local laws.
■When the card key battery needs to be replaced (if equipped)
The battery for the card key is available only at Lexus dealers. Your Lexus dealer
can replace the battery for you.
CAUTION
■Removed battery and other parts
These parts are small and if swallowed by a child, they can cause choking. Keep
away from children. Failure to do so could result in death or serious injury.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents.
●Always work with dry hands.
Moisture may cause the battery to rust.
●Do not touch or move any other components inside the remote control.
●Do not bend either of the battery terminals.
Page 482 of 626

When trouble arises5
481
IS250C/350C_U
5-1. Essential informationEmergency flashers.............. 482
If your vehicle needs to be towed................................ 483
If you think something is wrong ...................................... 489
Fuel pump shut off system.... 490 5-2. Steps to take in an
emergency
If a warning light turns on or a warning buzzer
sounds... .................................. 491
If a warning message is displayed................................ 500
If you have a flat tire (vehicles with standard
tires) ......................................... 513
If you have a flat tire (vehicles with run-flat
tires) ........................................ 522
If the engine will not start .... 524
If the shift lever cannot be shifted from P ....................... 526
If you lose your keys .............. 527
If the electronic key does not operate properly.......... 528
If the vehicle battery is discharged ............................ 532
If your vehicle overheats ..... 536
If the vehicle becomes stuck........................................ 539
If the retractable hardtop does not close ...................... 540
If your vehicle has to be stopped in an
emergency ............................ 550