Page 529 of 628

5158-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
Warning message and warning buzzer list
Warning messageDetails/Actions
(If equipped)
Indicates that:
• There is a high possibility of a frontal collision;
or
• The pre-crash braking function is operating
A buzzer also sounds.
Slow the vehicle by applying the brakes.
Indicates that the hybrid system was stopped with
the shift lever not in P
A buzzer also sounds.
Shift the shift lever to P.
Indicates that the hybrid system was stopped while
driving
A buzzer also sounds.
Stop the vehicle in a safe place such as the shoul-
der of a road.
(If equipped)
Indicates that your vehicle is nearing the vehicle
ahead (in vehicle-to-vehicle distance mode)
A buzzer also sounds.
Slow the vehicle by applying the brakes.
(If equipped)
Alerts the driver that the vehicle has deviated from
the lane (while the LDA [Lane Departure Alert]
system is operating)
The lane line on the side the vehicle has deviated
from flashes in yellow.
The warning buzzer sounds continuously.
Check around the vehicle and back to inside of
the lane lines.
(Flashes)
(Flashes)
(Flashes)
Page 533 of 628

5198-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
(If equipped)
Indicates that the dynamic radar cruise control sys-
tem is unable to judge vehicle-to-vehicle distance
A buzzer also sounds.
Turn off snow mode.
If the windshield wipers are on, turn them off or
set them to a mode other than AUTO or high
speed wiper operation.
(If equipped)
Indicates that the LDA (Lane Departure Alert) sys-
tem is suspended
The camera sensor temperature is higher than the
operation temperature range.
A buzzer also sounds.
Restart the LDA after driving for a while.
(If equipped)
Indicates that:
• The grille shutter system cannot operate; or
• The grille shutter is dirty or covered with ice
A buzzer also sounds.
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied and equipped professional.
(If equipped)
Indicates that a Blind Spot Monitor sensor or the
surrounding area on the bumper is dirty or covered
with ice
A buzzer also sounds.
Clean the sensor and its surrounding area on the
bumper.
(If equipped)
Indicates a malfunction in:
• The cruise control system; or
• The dynamic radar cruise control system
Press the “ON/OFF” button once to deactivate the
system, and then press the button again to reacti-
vate the system.
A buzzer also sounds.
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied and equipped professional.
(If equipped)
Indicates a malfunction in the LDA (Lane Depar-
ture Alert) system
A buzzer also sounds.
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied and equipped professional.
Warning messageDetails/Actions
Page 535 of 628

5218-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
Indicates that the power switch is turned off or
turned to ACCESSORY mode and the driver’s door
is opened while the lights are turned on
A buzzer also sounds.
Turn the lights off.
(If equipped)
Indicates that the moon roof is not fully closed
(with the power switch off, and the driver’s door
open)
A buzzer also sounds.
Close the moon roof.
Indicates that the windows are not fully closed
(with the power switch off, and the driver’s door
open)
A buzzer also sounds.
Close all the windows.
(If equipped)
Indicates that the windows and the moon roof are
not fully closed (with the power switch off, and the
driver’s door open)
A buzzer also sounds.
Close all the windows and the moon roof.
Indicates a malfunction in the brake override sys-
tem
A buzzer also sounds.
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied and equipped professional.
Indicates that engine oil level is low
A buzzer also sounds.
Check the level of engine oil, and add if neces-
sary.
Indicates that the hybrid system has overheated
This message may be displayed when driving
under severe operating conditions. (For example,
when driving up a long steep hill.)
A buzzer also sounds.
Stop and check. (P. 556)
Warning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
(Flashes)
Page 538 of 628

5248-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
*1: Refer to the separate “Lexus Service Booklet” or “Lexus Warranty Booklet”
for the maintenance interval applicable to your vehicle.
*2: For the EV drive mode operating conditions: P. 214
Indicates that the EV drive mode is not available*2
The reason the EV drive mode is not available
(the vehicle is idling, hybrid battery [traction bat-
tery] charge is low, speed is higher than the EV
drive mode operating speed range, accelerator
pedal is depressed too much) may be displayed.
A buzzer also sounds.
Use the EV drive mode when it becomes avail-
able.
Indicates that the EV drive mode has been automat-
ically canceled
*2
The reason the EV drive mode is not available
(the hybrid battery [traction battery] charge is
low, speed is higher than the EV drive mode
operating speed range, accelerator pedal is
depressed too much) may be displayed.
A buzzer also sounds.
Drive the vehicle for a while.
Warning messageDetails/Actions
(Except F
SPORT mod-
els)(F SPORT
models)
(Flashes) (Flashes)
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5258-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
Warning messages
The warning message illustrations used are intended as examples, and may differ
from the image that is actually displayed 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
functions
When the lane lines cannot be recognized
After changing the engine oil (if equipped)
Make sure to reset the oil change system. (P. 442)
Warning buzzer
P. 512
Page 541 of 628

5278-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
Once3
times
The electronic key was carried
outside the vehicle and a door
other than the driver’s door was
opened and closed while the
power 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
power switch was not turned off.
Turn the power switch off.
Bring the electronic key back
into the vehicle.
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-
tinu-
ous
An attempt was made to lock the
doors using the smart entry &
start system while the electronic
key was still inside the vehicle.
Retrieve the electronic key
from the vehicle and lock the
doors again.
Once
Con-
tinu-
ous
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 by pulling
on the outside door handle with
the electronic key still inside the
vehicle.
Retrieve the electronic key
from the vehicle and lock the
doors again.
Interior
buzzerExterior
buzzerWarning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
(Vehicles with the entry function)
(Flashes)
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5298-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
Indicates that:
• With the power switch off, the
doors were unlocked and then
the driver’s door was opened
and closed;
• The power switch was turned
to ACCESSORY mode with-
out starting the hybrid system;
or
• The shift lever was shifted to P
from another position with the
power switch in ON mode.
Press the power switch while
depressing the brake pedal.
Once
The power switch has been
turned off with the shift lever in a
position other than P.
Shift the shift lever to P.
Once
After the power 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 power switch off.
Power was turned off due to the
automatic power off function.
Next time when starting the
hybrid system, increase the
engine speed slightly and
maintain that level for approx-
imately 5 minutes to recharge
the 12-volt battery.
Con-
tinu-
ous
Indicates that the hybrid system
was stopped in an emergency
while driving
To restart the hybrid system,
shift the shift lever to N and
turn the power switch to ON
mode.
*
Interior
buzzerExterior
buzzerWarning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
Page 561 of 628

5478-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
One of the following may be the cause of the problem:
One or both of the 12-volt battery terminals may be disconnected.
The 12-volt battery may be discharged. (P. 551)
Contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional if the problem cannot be repaired, or if repair proce-
dures are unknown.
When the hybrid system does not start, the following steps can be used as
an interim measure to start the hybrid system if the power switch is func-
tioning normally:
Set the parking brake.
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for about 15 seconds while depressing
the brake pedal firmly.
Even if the hybrid system can be started using the above steps, the system
may be malfunctioning. Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly qualified and equipped profes-
sional.
The interior lights and headlights do not turn on, or the horn does
not sound.
Emergency start function
1
2
3
4