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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
Page 511 of 626
510
5-2. Steps to take in an emergency
IS250C/350C_U
Follow the correction procedures.After taking the specified steps to correct the suspected problem, check
that the warning light turns off.
InteriorbuzzerExterior buzzerMessageDetailsCorrection
procedure
Once
(Comes on for 10 seconds.)
(Flashing)
Indicates that an
attempt was made
to start the engine
without the elec-
tronic key being
present, or the
electronic key was
not functioning
normally.
Start the engine
with the elec-
tronic key
present.
*
Once3 times
(Flashing)
Indicates that a
door other than
the driver’s door
has been opened
or closed with the
“ENGINE START
STOP” switch in
any mode other
than OFF and the
electronic key
outside of the
detection area.
Confirm the loca-
tion of the elec-
tronic key.
Page 512 of 626
5
When trouble arises
511
5-2. Steps to take in an emergency
IS250C/350C_U
Once3 times
(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)(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. 4 4 9 )
Interior
buzzerExterior buzzerMessageDetailsCorrection
procedure
Page 513 of 626
512
5-2. Steps to take in an emergency
IS250C/350C_U
*: If the engine does not start when the electronic key is inside the vehicle, theelectronic key battery may be depleted or there may be difficulties receiving the
signal from the key. ( →P. 36)
Once
Indicates that a
door has been
opened or closed
and the “ENGINE
START STOP”
switch has been
switched twice to
ACCESSORY
mode from OFF.
Press the
“ENGINE START
STOP” switch
while applying the
brakes.
(Flashing)
Indicates that the
steering lock has
not released
within 3 seconds
of pressing the
“ENGINE START
STOP” switch.Press the
“ENGINE START
STOP” switch
again while turn-
ing the steering
wheel with the
brake pedal
depressed.
OnceIndicates that the
electronic key
does not operate
properly.
→P. 5 3 0
Interior
buzzerExterior buzzerMessageDetailsCorrection
procedure
Page 528 of 626
5
When trouble arises
527
5-2. Steps to take in an emergency
IS250C/350C_U
If you lose your keys
New genuine Lexus keys can be made by your Lexus dealer using the other
key and the key number stamped on your key number plate.
Page 529 of 626
528
5-2. Steps to take in an emergency
IS250C/350C_U
If the electronic key does not operate properly
Locking and unlocking the doors, unlocking the trunk
Use the mechanical key built in to the electronic keys to operate the
doors. (→ P. 2 9 )
Doors Remove the cover on the driver’s
door handle.
Locks both side doors
Unlocks the door
Tu r n i n g t h e k e y r e a r w a r d u n l o c k s
the driver's door. Turning the key
once again unlocks the passenger’s
door.
If communication between the electronic key and vehicle is interrupted
(→ P. 36) 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 or the engine can be started by following the procedure below.
STEP1
STEP2
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5
When trouble arises
529
5-2. Steps to take in an emergency
IS250C/350C_UAfter the operation is completed,
reinstall the cover.
Hook the upper claw of the cover
onto the upper catch on the vehi-
cle side, and then push on the
lower side of the cover.
Make sure that the lower claw of
the cover is securely fastened to
the lower catch on the vehicle side.
If the cover is not securely
attached, it may fall off while driv-
ing.
Tr u n k
Remove the cover using a
mechanical key.
Turn the mechanical key clock-
wise to open.
STEP3
STEP1
STEP2