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4617-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D56E)
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deionized water.
(Minimum temperature: -35 °C [-31 °F])
For more details about coolant, contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
■If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have any authorized Lexus dealer or repairer, or another duly
qualified and equipped professional, test the cap and check for leaks in the cooling sys-
tem.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or water filler cap.
( → P. 5 74 )
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water and
antifreeze must be used to provide proper lubrication, corrosion protection and cool-
ing. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
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4627-3. Do-it-yourself maintenance
IS300h_EE(OM53D56E)
Check the radiators and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
If any washer does not work or the
warning message appears on the multi-
information display, the washer tank
may be empty. Add washer fluid.
Radiators and condenser
CAUTION
■When the hybrid system is hot
Do not touch the radiators or condenser as they may be hot and cause serious injuries,
such as burns.
Washer fluid
CAUTION
■When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as washer fluid
contains alcohol and may catch fire if spilled on the engine etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle’s painted surfaces.
■Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.
Page 528 of 628

5288-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Warning message and warning buzzer list
Wa r n i n g m e s s a g eDetails/Actions
(If equipped)
Indicates that:
• There is a high possibility of a frontal collision; or
• The pre-crash braking function is operatingA buzzer also sounds.
→ Slow the vehicle by applying the brakes.
Indicates that the hybrid sy stem 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 driv-
ing
A buzzer also sounds.
→ Stop the vehicle in a safe place such as the shoulder
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)
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5358-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Indicates a malfunction in the brake override systemA buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates that engine oil level is low
A buzzer also sounds.
→ Check the level of engine oil, and add if necessary.
Indicates that the hybrid system has overheated
This message may be displayed when driving under
severe operating conditions. (For example, when driv-
ing up a long steep hill.)
A buzzer also sounds.
→ Stop and check. ( →P. 5 7 1 )
Indicates a malfunction in:
• The automatic headlight leveling system; or
• The Automatic High Beam system (if equipped)
• The LED headlight system (if equipped)
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates that the accelerator and brake pedal are being
depressed simultaneously
→Release the accelerator or brake pedal.
Maintenance of the hybrid battery (traction battery)
cooling component is required
The filter may be clogged, the air intake vent may be
blocked or there may be a gap in the duct
→ Have maintenance performed on the hybrid battery
(traction battery) cooling component by any autho-
rized Lexus dealer or repairer, or another duly qual-
ified and equipped professional.
Indicates that the washer fluid level is low
→Add washer fluid.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
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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
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5608-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. (→P. 5 6 4 )
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●There may be a malfunction in the immobilizer system. ( →P. 9 0 )
●There may be a malfunction in the steering lock system.
●The hybrid system may be malfunctioning due to an electrical problem such
as electronic key battery depletion or a blown fuse. However, depending on
the type of malfunction, an interim measure is available to start the hybrid sys-
tem. ( →P. 5 6 1 )
One of the following may be the cause of the problem:
●The 12-volt battery terminal connections may be loose or corroded.
●The 12-volt battery may be discharged. ( →P. 5 6 6 )
If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on the situation.
Check the following and perform the appropriate procedure:
The hybrid system will not start even though the correct starting proce-
dure is being followed. ( →P. 212)
The interior lights and headlights are dim, or the horn does not sound or
sounds at a low volume.
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
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5658-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
■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 electronic
key battery be replaced immediately when the battery is depleted. ( →P. 4 8 8 )
■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. 2 1 3 )
■When the electronic key does not work properly
●Make sure that the smart entry & start syst em has not been deactivated in the customi-
zation setting. If it is off, turn the function on.
(Customizable features →P. 5 9 1 )
●Check if battery-saving mode is set. If it is set, cancel the function. (→P. 1 5 0 )
CAUTION
■When using the mechanical key and operating the power windows or 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 mechanical key. It is possible for children and
other passengers to get caught in the power window or moon roof.
3