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120
2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
■If the engine does not start
The engine immobilizer system may not have been deactivated. (
→P. 7 2 )
■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 an hour with the shift lever
in P, the “ENGINE START STOP” switch will automatically turn OFF.
■Electronic key battery depletion
→P. 2 8
■When the electronic key battery is fully discharged
→P. 3 2 5
■Conditions affecting operation
→P. 2 6
■Note for the entry function
→P. 2 9
CAUTION
■When starting the engine
Always start the engine while sitting in the driver’s seat. Do not press the accelera-
tor while starting the engine under any circumstances.
Doing so may cause an accident resulting in death or serious injury.
■Caution when driving
Do not touch the “ENGINE START STOP” switch while driving.
Pressing and holding the “ENGINE START STOP” switch will stop the engine,
which may lead to an unexpected accident.
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145
2-3. Operating the lights and windshield wipers
2
When driving
08_IS350/250_U_(L/O_0708)
■Automatic light off system
●When the headlights comes on: The headlights and tail lights turn off 30 sec-
onds 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 all 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.
■If flashes... (vehicles with discharge headlights)
It may indicate a malfunction in the system. Contact your Lexus dealer.
■Customization that can be configured at Lexus dealer
Settings (e.g. light sensor sensitivity) can be changed. (Customizable features →P.
436)
NOTICE
■To prevent battery discharge
Do not leave the lights on longer than necessary when the engine is not running.
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233
3-3. Using the interior lights
3
Interior features
08_IS350/250_U_(L/O_0708)
■Illuminated entry system
The following interior lights come on automatically when you approach the vehicle
with the electronic key on your person. Note that the illuminated entry system oper-
ates only when the interior light switch (door position on/off) is on.
●Front overhead courtesy light
●Rear overhead courtesy light
●Outer foot light
The following lights turn on when any of the doors is unlocked or opened.
●Front interior light
●Rear interior lights
●Front foot well lighting
●Front door courtesy lighting
●Front scuff lighting
The following lights turn on for approximately 15 seconds when the “ENGINE
START STOP” switch is turned to OFF from the IGNITION ON or ACCESSORY
mode. (The lights turn off immediately if the doors are locked or the “ENGINE
START STOP” switch is set to ACCESSORY or IGNITION ON mode.)
●Front overhead courtesy light
●Rear overhead courtesy light
■To prevent the battery from being discharged
If the overhead courtesy lights and interior lights remain on when the door is not
fully closed and the interior light switch (door position on/off) is on, the lights will go
off automatically after 20 minutes.
■Customization that can be configured at Lexus dealer
Setting (e.g. The time elapsed before lights turn off) can be changed.
(Customizable features
→P. 4 3 6 )
Page 274 of 462

Maintenance and care4
273
08_IS350/250_U_(L/O_0708)
4-1. Maintenance and care ............................... 274
Cleaning and protecting the vehicle exterior.............. 274
Cleaning and protecting the vehicle interior .............. 277
4-2. Maintenance .................. 280 Maintenance requirements ....................... 280
General maintenance ......... 282
Emission inspection and maintenance (I/M)
programs............................... 285
4-3. Do-it-yourself maintenance ................ 286
Do-it-yourself service precautions ........................... 286
Hood ......................................... 289
Positioning a floor jack ......... 290
Engine compartment ............ 292
Tires ............................................ 306
Tire inflation pressure ............ 316 Wheels ...................................... 320
Air conditioning filter ........... 322
Electronic key battery.......... 325
Checking and replacing
fuses ........................................ 327
Headlight aim .......................... 341
Light bulbs................................ 342
Page 326 of 462
325
4-3. Do-it-yourself maintenance
4
Maintenance and care
08_IS350/250_U_(L/O_0708)
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
Page 327 of 462
326
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
■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.
CAUTION
■Removed battery and other parts
Keep away from children.
These parts are small and if swallowed by a child they can cause choking.
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 350 of 462

When trouble arises5
349
08_IS350/250_U_(L/O_0708)
5-1. Essential information................... 350
If your vehicle needs to be towed ..................................... 350
If you think something is wrong ...................................... 356
Fuel pump shut off system ..................................... 357
Event data recorder ............. 358
5-2. Steps to take in an emergency.................... 360
If a warning light turns on or a warning buzzer
sounds... ................................ 360
If a warning message is displayed ................................ 369
If you have a flat tire .............. 382
If the engine will not start ...... 391
If the shift lever cannot be shifted from P........................ 392
If you lose your keys ............... 393
If the electronic key does not operate properly .......... 394 If the vehicle battery is
discharged ............................ 397
If your vehicle overheats............................... 400
If the vehicle becomes stuck........................................ 402
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5
When trouble arises
379
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
InteriorbuzzerExterior buzzerWa r n i n g m e s s a g eDetailsCorrection
procedure
Once3 times
(Vehicles with an auto-
matic transmission)
(Flashing)
Indicates that the
driver’s door has
been opened or
closed with the
shift lever in P, the
“ENGINE START
STOP” switch in
any mode other
than OFF and the
electronic key
outside of the
detection area.
Tu r n t h e
“ENGINE START
STOP” switch
OFF or confirm
the location of the
electronic key.
OnceCon-
tinuous
(Displayed alternately)
(Vehicles with an auto-matic transmission)
(Flashing)
Indicates that the
driver’s door has
been opened or
closed (with the
shift lever out of in
P, t h e “ E N G I N E
START STOP”
switch in any
mode other than
OFF and the elec-
tronic key outside
of the detection
area).
• Shift the shift lever to P.
•Confirm the
location of the
electronic key.
Once
(Flashing)
Indicates that the
key battery is low.Replace the bat-
tery. (
→P. 3 2 5 )