Page 537 of 628
5378-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Indicates that operation of large electricity consuming
systems such as the air conditioning system are sus-
pended
→ Stop using unnecessary electric components to
reduce electricity consumpt ion. Wait a while until
the electric power supply is restored.
(If equipped)
Indicates that the LDA (Lane Departure Alert) system
cannot be used because the vehicle speed is lower than
approximately 50 km/h (32 mph)
→ Drive the vehicle at 50 km/h (32 mph) or higher.
Indicates that the EV drive mode is not available*
The reason the EV drive mode is not available (the
vehicle is idling, 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.
→ Use the EV drive mode when it becomes available.
Wa r n i n g m e s s a g eDetails/Actions
Page 538 of 628
5388-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
*: For the EV drive mode operating conditions: →P. 2 1 7
Indicates that the EV drive mode has been automatically
canceled
*
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.
Wa r n i n g m e s s a g eDetails/Actions
(Except F
SPORT models) (F SPORT
models)
(Flashes) (Flashes)
Page 539 of 628

5398-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
■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 messag e may not be displayed even if vehicle-to-
vehicle distance decreases:
●When the speed of the preceding vehicle matches or exceeds your vehicle speed
●When the preceding vehicle is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●When depressing the accelerator pedal
■The LDA (Lane Departure Alert) lane departure warning function (if equipped)
In the following situations, the warning messag e 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
■Resetting the message indicating maintenance is required
Make sure to reset the oil change system. ( →P. 4 5 8 )
■Warning buzzer
→P. 5 2 5
Page 540 of 628

5408-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
InteriorbuzzerExteriorbuzzerWarning messageDetails/Actions
Con-
tinuous The driver’s door was opened when
the shift lever was not in P and the
power 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 power 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
hybrid system.
→Start the hybrid system with the
electronic key present.
OnceCon-
tinuous
An attempt was made to exit the
vehicle with the electronic key and
lock the doors without first turning
the power switch off when the shift
lever was in P.
→Turn the power switch off and
lock the doors again.
(Flashes)
(Displayed alternately)
(Flashes)
(Flashes)
(Displayed alternately)
(Flashes)
Page 552 of 628

5528-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Start the hybrid system.
To inject the sealant and inflate the
tire, turn the compressor switch on.
Inflate the tire until the specified air
pressure is reached.
The sealant will be injected and the
pressure will surge and then gradu-
ally decrease.
The air pressure gauge will display
the actual tire inflation pressure
about 1 minute (5 minutes at low
temperature) after the switch is
turned on.
Inflate the tire until the specified air
pressure.
• Turn the compressor switch off and
then check the tire inflation pressure.
Being careful not to over inflate,
check and repeat the inflation pro-
cedure until the specified tire infla-
tion pressure is reached.
• If the tire inflation pressure is still lower than the specified point after inflation
for 35 minutes with the switch on, the tire is too damaged to be repaired. Turn
the compressor switch off and contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
• If the tire inflation pressure exceeds the specified air pressure, let out some air
to adjust the tire inflation pressure. ( →P. 5 5 6 , 5 8 6 )12
13
14
1
2
3
Page 564 of 628
5648-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Lexus emblem side of the
electronic key to the power switch.
When the electronic key is detected, a
buzzer sounds and the power switch will
turn to ON mode.
When the smart entry & start system is
deactivated in customization setting, the
power switch will turn to ACCESSORY
mode.
Firmly depress the brake pedal and check that is shown on the multi-
information display.
Press the power switch.
In the event that the hybrid system still cannot be started, contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional.
Starting the hybrid system
1
2
3
4
Page 571 of 628

5718-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
●The needle of the engine coolant temperature gauge (→P. 109) enters the
red zone or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.)
●“Hybrid System Overheat” is shown on the multi-information display.
●Steam comes out from under the hood.
■If the needle of the engine coolant temperature gauge enters the red zone
Stop the vehicle in a safe place and turn off the air conditioning system, and
then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently, inspect
the hoses and radiator core (radi-
ator) for any leaks. Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.
Reservoir
“FULL”
“LOW”
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2
4
1
2
3
Page 572 of 628

5728-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Add coolant if necessary.
Water can be used in an emergency
if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to check
that the radiator cooling fans operate and to check for coolant leaks from
the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air
flow. If it is difficult to check these, turn the air conditioning system on and off
repeatedly.
(The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the hybrid system immediately and contact any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
If the fans are operating:
Have the vehicle inspected at the nearest authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
■If “Hybrid System Overheat” is shown on the multi-information displayStop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has
cooled down, inspect the hoses
and radiator core (radiator) for
any leaks.Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
5
6
7
1
2
3
1
2