Page 450 of 628

4367-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
CAUTION
The engine compartment contains many mechanisms and fluids that may move
suddenly, become hot, or become electrically energized. To avoid death or seri-
ous injury, observe the following precautions.
When working on the engine compartment
Make sure that the “ACCESSORY” or “IGNITION ON” on the multi-infor-
mation display and the “READY” indicator are both off.
Keep hands, clothing and tools away from the moving fan and engine drive
belt.
Be careful not to touch the engine, power control unit, radiator, exhaust mani-
fold, etc. right after driving as they may be hot. Oil and other fluids may also
be hot.
Do not leave anything that may burn easily, such as paper and rags, in the
engine compartment.
Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are
flammable.
Take care because brake fluid can harm your hands or eyes and damage
painted surfaces. If fluid gets on your hands or in your eyes, flush the affected
area with clean water immediately.
If you still experience discomfort, consult a doctor.
When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fans may automati-
cally start to run if the air conditioning is on and/or the coolant temperature is
high. (P. 446)
Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from
getting in your eyes.
NOTICE
If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear
due to dirt in the air.
If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear
or when the fluid level in the accumulator is high.
If the reservoir needs frequent refilling, it may indicate a serious problem.
Page 453 of 628
4397-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
12-volt battery
P. 447
Engine compartment
Power control unit coolant res-
ervoir (P. 444)
Engine oil level dipstick
(P. 440)
Engine coolant reservoir
(P. 444)
Engine oil filler cap
(P. 441)Fuse box (P. 475)
Washer fluid tank (P. 446)
Electric cooling fans
Condenser (P. 446)
Power control unit coolant
radiator (P. 446)
Engine coolant radiator
(P. 446)1
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3
4
5
6
7
8
9
10
Page 458 of 628
4447-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Engine coolant reservoir
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to
the “FULL” line. (P. 555)
Power control unit coolant reservoir
The coolant level is satisfactory if it is between the “F” and “L” lines on
the reservoir when the hybrid system is cold.
Reservoir cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up to the “F”
line.
(P. 555)
Coolant
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2
3
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Page 459 of 628

4457-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
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% deion-
ized water. (Minimum temperature: -35C [-31F])
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 system.
CAUTION
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or water
filler cap. (P. 558)
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 pro-
tection and cooling. 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.
Page 462 of 628

4487-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
The meanings of each caution symbol on the top of the 12-volt battery are
as follows:
Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flammable
and explosive. Therefore, observe the following precautions before recharging:
If recharging with the 12-volt battery installed on the vehicle, be sure to discon-
nect the ground cable.
Make sure the power switch on the charger is off when connecting and discon-
necting the charger cables to the 12-volt battery.
After recharging/reconnecting the 12-volt battery
The hybrid system may not start. Follow the procedure below to initialize the
system.
Shift the shift lever to P.
Open and close any of the doors.
Restart the hybrid system.
Unlocking the doors using the smart entry & start system may not be possible
immediately after reconnecting the 12-volt battery. If this happens, use the
wireless remote control or the mechanical key to lock/unlock the doors.
Start the hybrid system with the power switch in ACCESSORY mode. The
hybrid system may not start with the power switch turned off. However, the
hybrid system will operate normally from the second attempt.
The power switch mode is recorded by the vehicle. If the 12-volt battery is
reconnected, the vehicle will return the power switch mode to the status it was
in before the 12-volt battery was disconnected. Make sure to turn off the power
switch before disconnecting the 12-volt battery. Take extra care when connect-
ing the 12-volt battery if the power switch mode prior to the 12-volt battery
being disconnected is unknown.
If the system will not start even after multiple attempts at all the methods above,
contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
Caution symbols
No smoking, no naked
flames, no sparks12-volt battery acid
Shield eyesNote operating instruc-
tions
Keep away from childrenExplosive gas
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2
3
Page 466 of 628

4527-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the power switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation
pressure level. (P. 570)
Make sure to adjust the tire pressure to the specified cold tire inflation pres-
sure level. The tire pressure warning system will operate based on this pres-
sure level.
Turn the power switch to ON mode.
Press and hold the tire pressure
warning reset switch until the
tire pressure warning light
blinks slowly 3 times.
Wait for a few minutes with the power switch in ON mode and then
turn the power switch off.
Registering ID codes
The tire pressure warning valve and transmitter is equipped with a
unique ID code. When replacing a tire pressure warning valve and
transmitter, it is necessary to register the ID code. Have the ID code
registered by any authorized Lexus dealer or repairer, or another duly
qualified and equipped professional.
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2
3
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5
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4547-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Situations in which the tire pressure warning system may not operate properly
In the following cases, the tire pressure warning system may not operate prop-
erly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment)
tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• Lock nuts are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehicle, particularly around the wheels
or wheel housings.
• If the tire inflation pressure is extremely higher than the specified level.
• If tires not equipped with tire pressure warning valves and transmitters are
used.
• If the ID code on the tire pressure warning valves and transmitters is not reg-
istered in the tire pressure warning computer.
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large dis-
play, airport or other facility that generates strong radio waves or electrical
noise
• When carrying a portable radio, cellular phone, cordless phone or other
wireless communication device
When the vehicle is parked, the time taken for the warning to start or go off
could be extended.
When tire inflation pressure declines rapidly for example when a tire has burst,
the warning may not function.
The initialization operation
Make sure to carry out initialization after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carrying out initialization or tire infla-
tion pressure adjustment.
If you have accidentally turned the power switch off during initialization, it is
not necessary to press the reset switch again as initialization will restart auto-
matically when the power switch has been turned to ON mode for the next time.
If you accidentally press the reset switch when initialization is not necessary,
adjust the tire inflation pressure to the specified level when the tires are cold,
and conduct initialization again.
Warning performance of the tire pressure warning system
The warning of the tire pressure warning system will change in accordance with
the conditions under which it was initialized. For this reason, the system may
give a warning even if the tire pressure does not reach a low enough level, or if
the pressure is higher than the pressure that was adjusted to when the system was
initialized.
Page 484 of 628
4707-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Turn the power switch off.
Open the glove box. Lift up the
side with the stay, disconnect the
stay tabs and remove the partition
by pulling horizontally.
Press the tabs and remove the fil-
ter cover.
Press the tabs and remove the fil-
ter case.
Air conditioning filter
The air conditioning filter must be changed regularly to maintain air con-
ditioning efficiency.
Removal method
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