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435
7
Maintenance and care
IS300h_EE(OM53B95E)7-3. Do-it-yourself maintenance
Do-it-yourself service precautions
If you perform maintenance by yourself, be sure to follow the correct
procedure as given in these sections.
ItemsParts and tools
12-volt battery
condition (P.
447)•Grease
• Conventional wrench (for terminal clamp bolts)
Engine/power con-
trol unit coolant
level (P. 444)
• “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 pre-mixed with
50% coolant and 50% deionized water.
• Funnel (used only for adding coolant)
Engine oil level
(P. 440)
• “Toyota Genuine Motor Oil” or equivalent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses (P. 475)• Fuse with same amperage rating as original
Light bulbs
(P. 479)
• Bulb with same number and wattage rating as original
• Phillips-head screw-
driver• Flathead screwdriver
• Wrench
Radiators and con-
denser (P. 446)
Tire inflation pres-
sure (P. 466)• Tire pressure gauge• Compressed air source
Washer fluid
(P. 446)• Water or washer fluid containing antifreeze (for winter
use)
• Funnel (used only for adding water or washer fluid)
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
2
3
4
5
6
7
8
9
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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 460 of 628

4467-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
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
condition, 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 570 of 628

5568-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
The needle of the engine coolant temperature gauge (P. 110) 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 sys-
tem, 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 (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.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
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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.
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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.
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