
5127-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
WARNING
The engine compartment contains many mechanisms and fluids that may move suddenly, become hot, or become electrically energize d. To avoid death or serious injury, observe
the following precautions.
■When working on the engine compartment
●Make sure that the “ACCESSORY” or “I GNITION ON” on the multi-information
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 manifold, 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 flamma-
ble.
●Take care because brake fluid can harm yo ur hands or eyes and damage painted sur-
faces. If fluid gets on your hands or in your eyes, flush the affected area with clean
water immediately. If you still experience disc omfort, 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 elec tric cooling fans may automatically start to
run if the air conditioning is on and/ or the coolant temperature is high. (P. 521)
■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 f ilter 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 freq uent refilling, it may indicate a serious problem.

5187-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
■After changing the engine oil
The engine oil maintenance data should be reset. Perform the following procedures:
Select on the multi- information display. (P. 119)
Press the or meter control switch on the steering wheel to select “Vehicle
Settings” then “Oil Maintenance” . (To confirm setting, press .)
Select “Yes” and then press .
A message is displa yed on the multi-information display.
WARNING
■Used engine oil
●Used engine oil contains potentially harmful contaminants which may cause skin dis-
orders such as inflammation and skin cance r, so care should be taken to avoid pro- longed and repeated contact . To remove used engine oil from your skin, wash
thoroughly with soap and water.
●Dispose of used oil and filters only in a sa fe and acceptable manner. Do not dispose of used oil and filters in household tras h, in sewers or onto the ground.
Call any authorized Lexus re tailer or Lexus authorized repairer, or any reliable
repairer, service station or auto parts st ore for information concerning recycling or disposal.
●Do not leave used engine oil within the reach of children.
NOTICE
■To prevent serious engine damage
Check the oil level on a regular basis.
■When replacing the engine oil
●Be careful not to spill engine oil on the vehicle components.
●Avoid overfilling, or the engine could be damaged.
●Check the oil level on the dipstick every time you refill the vehicle.
●Be sure the engine oil filler cap is properly tightened.
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5207-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
■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 mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -35 C [-31F])
For more details about coolant, contact any authorized Lexus retailer or Lexus autho-
rized repairer, or an y reliable repairer.
■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 retailer or Lexus authorized repairer, or any reliable repairer, test the cap an d check for leaks in the cooling system.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or water filler cap. ( P. 636)
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.

5217-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
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 retailer or Lexus
authorized repairer, or any reliable repairer.
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
WARNING
■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
WARNING
■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 an tifreeze 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.

5237-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
The meanings of each caution symbol on the top of the 12-volt battery are as fol-
lows:
■Before recharging
When recharging, the 12-volt battery produc es 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 disconnect the
ground cable.
●Make sure the power switch on the charge r is off when connecting and disconnecting
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 immedi- ately 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 sys- tem 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 connecting 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 ev en after multiple attempts at all the methods above, contact
any authorized Lexus retailer or Lexus author ized repairer, or any reliable repairer.
Caution symbols
No smoking, no naked flames, no sparks12-volt battery acid
Shield eyesNote operating instructions
Keep away from childrenExplosive gas
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5247-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
WARNING
■Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may produce
hydrogen gas which is flammable and explosive. To reduce the risk of death or serious
injury, take the following precautions while working on or near the 12-volt battery:
●Do not cause sparks by touching the 12-volt battery terminals with tools.
●Do not smoke or light a match near the 12-volt battery.
●Avoid contact with eyes, skin and clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when working near the 12-volt battery.
●Keep children away from the 12-volt battery.
■Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charge the 12-volt battery in
a garage or closed room where th ere is insufficient ventilation.
■How to recharge the 12-volt battery
Only perform a slow charge (4 A — 5 A). The 12-volt battery may explode if charged at
a quicker rate.
■Emergency measures re garding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medical attention. If possible, continue to apply wa ter with a sponge or cloth while traveling to
the nearest medical facility.
●If electrolyte gets on your skin Wash the affected area thoroughly. If you feel pain or burning, get medical attention
immediately.
●If electrolyte gets on your clothes It can soak through clothing on to your sk in. Immediately take off the clothing and fol-
low the procedure above if necessary.
●If you accidentally swallow electrolyte Drink a large quantity of water or milk . Get emergency medical attention immedi-
ately.
■When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may cause gas (hydro-
gen) to enter the passenger compartm ent, causing a fire or explosion.
For replacement of the 12-volt battery, contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.
NOTICE
■When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating. Also, be sure
all accessories are turned off.

5267-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
Rotate the tires in the order shown.
To equalize tire wear and help extend ti re life, Lexus recommends that tire rota-
tion is carried out approximately every 10000 km (6000 miles).
Do not fail to initialize the tire pressu re warning system after tire rotation.
Your vehicle is equipped with a tire pressure warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure before
serious problems arise.
If the tire pressure drops below a predeter mined level, the driver is warned by a
warning light. ( P. 578)
◆Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pr essure warning valves and transmitters
must also be installed.
When new tire pressure wa rning valves and transmitters are installed, new ID
codes must be registered in the tire pressure warning computer and the tire
pressure warning system must be initia lized. Have tire pressure warning valve
and transmitter ID codes registered by any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer. ( P. 527)
Tire rotation
Vehicles with front and rear tires of
the same size
Vehicles with front and rear tires of
differing sizes
FrontFront
Tire pressure warning system

5277-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
◆Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following circum-
stances:
●When rotating the tires.
●When the tire inflation pressure is ch anged such as when changing travel-
ing speed or load weight.
●When changing the tire size.
When the tire pressure warning system is initialized, the current tire inflation
pressure is set as the benchmark pressure.
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the power switch off.
Initialization cannot be performe d while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation pressure
level. ( P. 652)
Make sure to adjust the tire pressure to the specified cold tire inflation pressure
level. The tire pressure warning system will operate based on this pressure 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 tran smitter is equipped with a unique ID
code. When replacing a tire pressure warning valve and transmitter, it is nec-
essary to register the ID code. Have th e ID code registered by any authorized
Lexus retailer or Lexus authorized repairer, or any reliable repairer.
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