Page 482 of 586

4818-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
■Wa r n i n g m e s s a g e s
The warning message illustrations used are intended as examples, and may differ from
the image that is actually displaye d on the multi-information display.
■Warning message in radar cruise mode (if equipped)
In the following situations, the warning message may not be displayed even if vehicle-to-
vehicle distance decreases:
●When your vehicle and the vehicle ahead are traveling at the same speed or the vehicle
ahead is traveling more quickly than your vehicle
●When the vehicle ahead is traveling at a very low speed
●Immediately after cruise control speed is set
●At the instant the accelerator pedal is depressed
■The LDA (Lane Departure Alert) lane departure warning function (if equipped)
In the following situations, the warning message will not be displayed even if a lane line is
crossed.
●When the vehicle speed deviates from the operating range of the LDA system func-
tions
●When the lane lines cannot be recognized
■Reset the maintenance data (U.S.A. only)
Make sure to reset the oil change system. ( →P. 4 0 3 )
■Conditions that the tire pressure warning system may not function properly
→P. 4 2 8
■Warning buzzer
→P. 4 6 9
Page 483 of 586

4828-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
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 485 of 586

4848-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
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. 500), 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 498 of 586

4978-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
One of the following may be the cause of the problem:
●One or both of the battery terminals may be disconnected.
●The battery may be discharged. (→P. 5 0 2 )
●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 normally:
Set the parking brake.
Shift the shift lever to P.
Turn the engine switch to ACCESSORY mode.
Press and hold the engine switch for about 15 seconds while depressing the
brake pedal firmly.
Even if the engine can be started using the above steps, the system may be mal-
functioning. Have the vehicle inspected by your Lexus dealer.
The starter motor does not turn over , the interior lights and headlights
do not turn on, or the horn does not sound.
Emergency start function
1
2
3
4
Page 502 of 586

5018-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
■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 recommended that the electronic
key battery be replaced immediately when the battery is depleted. (→P. 4 3 9 )
■Changing engine switch modes
Release the brake pedal and press the engine switch in step above.
The engine does not start and modes will be changed each time the switch is pressed.
( → P. 1 6 0 )
■When the electronic key does not work properly
●Make sure that the smart access system with push-button start has not been deacti-
vated in the customization setting. If it is off, turn the function on.
(Customizable features →P. 5 3 7 )
●Check if battery-saving mode is set. If it is set, cancel the function. (→P. 1 1 5 )
CAUTION
■When using the mechanical key and operating the power windows and moon roof
Operate the power window or moon roof after checking to make sure that there is no
possibility of any passenger having any of their body parts caught in the window or
moon roof.
Also, do not allow children to operate the mech anical key. It is possible for children and
other passengers to get caught in power window and moon roof.
3
Page 504 of 586

5038-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
Connect the jumper cables according to the following procedure:Connect a positive jumper cable clamp to the positive (+) battery terminal
on your vehicle.
Connect the clamp on the other end of the positive cable to the positive (+)
battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery terminal on the
second vehicle.
Connect the clamp at the other end of the negative cable to a solid, station-
ary, unpainted metallic point away from the battery and any moving parts,
as shown in the illustration.
Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 5 minutes to recharge the battery of
your vehicle.
Open and close any of the doors of your vehicle with the engine switch off.
Maintain the engine speed of the second vehicle and start the engine of your
vehicle by turning the engine switch to IGNITION ON mode.
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 vehicle inspected at your Lexus dealer as soon
as possible.3
1
2
3
4
4
5
6
7
Page 505 of 586

5048-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
■Starting the engine when the battery is discharged
The engine cannot be started by push-starting.
■To prevent battery discharge
●Turn off the headlights and the audio system while the engine is off.
●Turn off any unnecessary electrical components 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 discharge gradually even when the vehicle is not
in use, due to natural discharge and the draining effects of certain electrical appliances. 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 battery
●Make sure that the key is not inside the vehicle when recharging or replacing the bat-
tery. The key may be locked in the vehicle if the alarm is activated. ( →P. 7 2 )
●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.
●The engine may not start on the first attempt after the battery has recharged but will
start normally after the second attempt. This is not a malfunction.
●The engine switch mode is memorized by the vehicle. When the battery is recon-
nected, the system will return to the mode it was in before the battery was discharged.
Before disconnecting the battery, turn the engine switch off.
If you are unsure what mode the engine switch was in before the battery discharged, be
especially careful when reconnecting the battery.
Page 540 of 586

5399-2. Customization
9
Vehicle specifications
IS350/250_U (OM53C50U)
*1: For details about each function: →P. 8 8
*2: The default setting varies according to country.
*3:Except F SPORT models
*4: Some status screens cannot be registered (indicated on multi-information display).
*5: 2 of the following items: current fuel consumption, average fuel economy (after reset),
average fuel economy (after refuel), average fuel economy (after start), average vehi-
cle speed (after reset), average vehicle speed (after start), distance (driving range),
distance (after start), elapsed time (after reset), elapsed time (after start), blank.
*6:F SPORT models
■Door lock ( →P. 103, 109, 499)
REV indicator*65000 rpm
2000 to 6600
rpm
—O—
OFF
REV peak*6ONOFF—O—
Function*1Default settingCustomized setting123
FunctionDefault settingCustomized setting
Unlocking using a mechani-
cal key
Driver’s door
unlocked in one
step, all doors
unlocked in two steps
All doors unlocked in one step——O
Automatic door lockShifting the shift
lever to position
other than P
Off
O—OVehicle speed is
approximately 12
mph (20 km/h) or higher
Automatic door unlockShifting the shift
lever to POff
O—ODriver’s door is opened
Locking/unlocking of the
trunk when all doors are
locked/unlockedOnOff——O
123