Page 543 of 628

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 544 of 628
5308-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
*: The hybrid system may not be restarted depending on the vehicle condition.
Warning messages
P. 525
Warning buzzer
P. 512
Once
Indicates that the power switch
has been pressed while driving
Except when emergency stop-
ping of the vehicle is needed,
immediately release the power
switch.
Interior
buzzerExterior
buzzerWarning messageDetails/Actions
(Flashes)
Page 564 of 628

5508-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
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 set-
ting, 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.
Stopping the hybrid system
Shift the shift lever to P and press the power switch as you normally do when
stopping the hybrid system.
Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the elec-
tronic key battery be replaced immediately when the battery is depleted. (P.
472)
Alarm (if equipped)
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set, the
alarm may be triggered.
Changing power switch modes
Release the brake pedal and press the power switch in step above.
The hybrid system does not start and modes will be changed each time the switch
is pressed. (P. 210)
When the electronic key does not work properly
Make sure that the smart entry & start system has not been deactivated in the
customization setting. If it is off, turn the function on.
(Customizable features P. 575)
Check if battery-saving mode is set. If it is set, cancel the function. (P. 150)
Starting the hybrid system
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Page 571 of 628

5578-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fan operates and to check for coolant
leaks from the radiator or hoses.
The fan operates when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fan is 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 fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the hybrid system immediately and contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional.
If the fan is 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 dis-
play
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
4
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Page 572 of 628
5588-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
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
authorized Lexus dealer or
repairer, or another duly quali-
fied and equipped professional.
The coolant level is satisfac-
tory if it is between the “F”
and “L” lines on the reservoir.
Reservoir
“F”
“L”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and check for the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
If the message is not displayed:
Have the vehicle inspected at the nearest authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
3
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4
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3
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Page 573 of 628

5598-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
CAUTION
When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot.
After the hybrid system has been turned off, check that the “READY” indica-
tor is off.
When the hybrid system operating, the gasoline engine may automatically
start, or the cooling fan may suddenly operate even if the gasoline engine
stops. Do not touch or approach rotating parts such as the belt and fan, which
may lead to fingers or clothing (especially a tie, a scarf or a muffler) getting
caught, resulting in serious injury.
NOTICE
When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently. Add-
ing cool coolant to a hot hybrid system too quickly can cause damage to the
hybrid system.
To prevent damage to the cooling system
Observe the following precautions:
Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).
When using coolant additives, use genuine Toyota products or equivalent.
Do not loosen the coolant reservoir caps
or water filler cap while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.
Page 574 of 628
5608-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
Stop the hybrid system. Set the parking brake and shift the shift lever to
P.
Remove the mud, snow or sand from around the rear wheels.
Place wood, stones or some other material under the rear wheels to
help provide traction.
Restart the hybrid system.
Shift the shift lever to D or R and release the parking brake. Then,
while exercising caution, depress the accelerator pedal.
When it is difficult to free the vehicle
If the vehicle becomes stuck
Carry out the following procedures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Press to turn off TRC.
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Page 600 of 628

585
9 9-2. Customization
Vehicle specifications
IS300h_EE(OM53B95E)
Vehicle customization
When the speed-detecting automatic door lock and shift-linked automatic door
lock are both on, the door lock operates as follows.
• When shifting the shift lever to any position other than P, all the doors will
be locked.
• If the vehicle is started with all doors locked, the speed-detecting automatic
door lock will not operate.
• If the vehicle is started with any door unlocked, the speed-detecting auto-
matic door lock will operate.
When the smart entry & start system is off, the entry unlock function cannot be
customized.
When the doors remain closed after unlocking the doors and the timer activated
automatic door lock function activates, signals will be generated in accordance
with the operation buzzer volume and operational signal (Emergency flashers)
function settings.
When customizing using the Remote Touch or Lexus Display Audio controller
Stop the vehicle in a safe place, apply the parking brake, and shift the shift lever
to P. Also, to prevent 12-volt battery discharge, leave the hybrid system operating
while customizing the features.
CAUTION
During customization
As the hybrid system needs to be operating during customization, ensure that
the vehicle is parked in a place with adequate ventilation. In a closed area such
as a garage, exhaust gases including harmful carbon monoxide (CO) may col-
lect and enter the vehicle. This may lead to death or a serious health hazard.
NOTICE
During customization
To prevent 12-volt battery discharge, ensure that the hybrid system is operating
while customizing features.