Page 428 of 573
4277-3. Do-it-yourself maintenance
7
Maintenance and care
IS350/250_U (OM53758U)
●Flathead screwdriver
●Small flathead screwdriver
●Lithium battery CR2032
Take out the mechanical key.
Remove the cover.
To prevent damage to the key, wrap the
tip of the screwdriver with tape.
Remove the depleted battery.
Insert a new battery with the “+” termi-
nal facing up.
Electronic key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
1
2
3
Page 429 of 573

4287-3. Do-it-yourself maintenance
IS350/250_U (OM53758U)
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent type recommended by the manufacturer.
●Dispose of used batteries according to 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.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-button start and wireless remote control will not
function properly.
●The operational range will be reduced.
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 component inside the remote control.
●Do not bend either of the battery terminals.
Page 446 of 573
445
When trouble arises8
IS350/250_U (OM53758U)
8-1. Essential informationEmergency flashers .................. 446
If your vehicle has to be stopped in
an emergency........................... 447
8-2. Steps to take in an emergency
If your vehicle needs to be towed ................................448
If you think something is wrong ....................................... 453
Fuel pump shut off system ...... 454
If a warning light turns on or a warning buzzer sounds ..... 455
If a warning message is displayed ..................................461
If you have a flat tire................... 475
If the engine will not start ........485
If the shift lever cannot be shifted from P ..................... 487
If the electronic key does not operate properly ............ 488
If the vehicle battery is discharged ............................. 490
If your vehicle overheats ......... 494
If the vehicle becomes stuck ..............................................497
Page 472 of 573

4718-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
InteriorbuzzerExteriorbuzzerWa r n i n g m e s s a g eDetails/Actions
Con-
tinuous The driver’s door was opened when
the shift lever was not in P and the
engine switch was not turned off.
Shift the shift lever to P.
Con-
tinuousCon-
tinuous
The driver’s door was opened and
closed while the electronic key was
not in the vehicle, the shift lever was
not in P and the engine switch was
not turned off.
Shift the shift lever to P.
Bring the electronic key back
into the vehicle.
Once The electronic key is not detected
when an attempt is made to start the
engine.
Start the engine with the elec-
tronic key present.
OnceCon-
tinuous
An attempt was made to exit the
vehicle with the electronic key and
lock the doors without first turning
the engine switch off when the shift
lever was in P.
Turn the engine switch off and
lock the doors again.
Once3 times
The electronic key was carried out-
side the vehicle and a door other
than the driver’s door was opened
and closed while the engine switch
was in a mode other than off.
Bring the electronic key back
into the vehicle.
The driver’s door was opened and
closed while the electronic key was
not in the vehicle, the shift lever was
in P and the engine switch was not
turned off.
Turn the engine switch off.
Bring the electronic key back
into the vehicle.
(Flashes)
(Displayed alternately)
(Flashes)
(Flashes)
(Displayed alternately)
(Flashes)
(Flashes)
Page 473 of 573

4728-2. Steps to take in an emergency
IS350/250_U (OM53758U)
9 times
An attempt was made to drive when
the electronic key was not inside the
vehicle.
Confirm that the electronic key
is inside the vehicle.
Con-
tinuous
An attempt was made to lock the
doors using the smart access system
with push-button start while the
electronic key was still inside the
vehicle.
Retrieve the electronic key
from the vehicle and lock the
doors again.
OnceCon-
tinuous
An attempt was made to lock either
front door by opening a door and
putting the inside lock button into
the lock position, then closing the
door with the electronic key still
inside the vehicle.
Retrieve the electronic key
from the vehicle and lock the
doors again.
Once
The electronic key has a low battery.
Replace the electronic key bat-
tery. ( P. 4 2 7 )
Once
The steering lock could not be
released within 3 seconds of the
engine switch being pressed.
Press the engine switch while
depressing the brake pedal and
moving the steering wheel left
and right.
Once
Indicates a malfunction in the smart
access system with push-button
start
Have the vehicle inspected by
your Lexus dealer.
Interior
buzzerExteriorbuzzerWa r n i n g m e s s a g eDetails/Actions
(Flashes)
(Flashes)
(Flashes)
(Flashes)
(Flashes)
Page 474 of 573

4738-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
Once
• When the doors were unlockedwith the mechanical key and then
the engine switch was pressed,
the electronic key could not be
detected in the vehicle.
• The electronic key could not be detected in the vehicle even after
the engine switch was pressed
two consecutive times.
Touch the electronic key to the
engine switch while depressing
the brake pedal.
Once
During an engine starting proce-
dure in the event that the electronic
key was not functioning properly
( P. 489), the engine switch was
touched with the electronic key.
Press the engine switch within
10 seconds of the buzzer sound-
ing.
Indicates that:
• With the engine switch off, the
doors were unlocked and then the
driver's door was opened and
closed
• The engine switch was turned to ACCESSORY mode without
starting the engine
• The shift lever was shifted to P or N from another shift position with
the engine switch in IGNITION
ON mode.
Press the engine switch while
depressing the brake pedal.
Once
The engine switch has been turned
off with the shift lever in a position
other than P or N.
Shift the shift lever to P.
Once
After the engine switch has been
turned off with the shift lever in a
position other than P, the shift lever
has been shifted to P.
Turn the engine switch off.
Interior
buzzerExteriorbuzzerWa r n i n g m e s s a g eDetails/Actions
(Flashes)
(Flashes)
(Flashes)
Page 486 of 573

4858-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
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 following correct starting procedures.
(P. 1 5 9 )
●There may be a malfunction in the engine immobilizer system. ( P. 6 9 )
One of the following may be the cause of the problem:
●The battery terminal connections may be loose or corroded.
●The battery may be discharged. ( P. 4 9 0 )
The engine starting system may be malfun ctioning 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. 4 8 6 )
If the engine will not start
If the engine will not start even though correct starting procedures are being
followed ( P. 159), consider each of the following points:
The engine will not start even thoug h the starter motor operates nor-
mally.
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
Page 489 of 573

4888-2. Steps to take in an emergency
IS350/250_U (OM53758U)
■Doors
Use the mechanical key (P. 99) in
order to perform the following oper-
ations:
Locks all the doors
Closes the windows and moon
roof (turn and hold)
*
Unlocks the door
Turning the key rearward unlocks the
driver’s door. Turning the key once
again within 5 seconds unlocks the
other doors.
Opens the windows and moon roof (turn and hold)*
*
: This setting must be customized at your Lexus dealer.
■Tr u n k
Turn the mechanical key clockwise
to open.
If the electronic key does not operate properly
If communication between the electronic key and vehicle is interrupted ( P.
116) or the electronic key cannot be used because the battery is depleted, the
smart access system with push-button start and wireless remote control can-
not be used. In such cases, the doors and trunk can be opened and the engine
can be started by following the procedure below.
Locking and unlocking the doors, un locking the trunk and key linked
functions
1
2
3
4