
4247-3. Do-it-yourself maintenance
IS250_EE(OM53C51E)
■Before recharging
When recharging, the battery produces hydrogen gas which is flammable and explosive.
Therefore, observe the following before recharging:
●If recharging with the battery installed on the vehicle, be sure to disconnect the ground
cable.
●Make sure the power switch on the charger is off when connecting and disconnecting
the charger cables to the battery.
■After recharging/reconnecting the battery
The engine 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 engine.
●Unlocking the doors using the smart entry & start system may not be possible immedi-
ately after reconnecting the battery. If this happens, use the wireless remote control or
the mechanical key to lock/unlock the doors.
●Start the engine with the engine switch in ACCESSORY mode. The engine may not
start with the engine switch turned off. However, the engine will operate normally from
the second attempt.
●The engine switch mode is recorded by the vehicle. If the battery is disconnected and
reconnected, the vehicle will return the engine switch mode to the status it was in
before the battery was disconnected. Make sure to turn off the engine before discon-
necting the battery. Take extra care when connecting the battery if the engine switch
mode prior to the battery being disconnected is unknown.
If the engine will not start even after multiple attempts at all the methods contact any
authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
1
2
3

4257-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)
CAUTION
■Chemicals in the battery
Batteries contain 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 battery:
●Do not cause sparks by touching the battery terminals with tools.
●Do not smoke or light a match near the battery.
●Avoid contact with eyes, skin and clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when working near the battery.
●Keep children away from the battery.
■Where to safely charge the battery
Always charge the battery in an open area. Do not charge the battery in a garage or
closed room where there is insufficient ventilation.
■Emergency measures regarding 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 water 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 skin. 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.
NOTICE
■When recharging the battery
Never recharge the battery while the engine is running. Also, be sure all accessories
are turned off.
■When adding distilled water
Avoid overfilling. Water spilled during battery recharging may cause corrosion.

4317-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)
■Situations in which the tire pressure warning system may not operate properly (vehi-
cles with a tire pressure warning system)
●In the following cases, the tire pressure warning system may not operate properly.
• 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 registered
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 display, air-
port 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 (vehicles with a tire pressure warning system)
●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 inflation pres-
sure adjustment.
●If you have accidentally turned the engine switch off during initialization, it is not neces-
sary to press the reset switch again as initialization will restart automatically when the
engine switch has been turned to IGNITION 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 initial-
ization again.
■Warning performance of the tire pressure warning system (if equipped)
The warning of the tire pressure warning system will change in accordance with the con-
ditions 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.

5208-2. Steps to take in an emergency
IS250_EE(OM53C51E)
NOTICE
■When performing an emergency repair
●Perform the emergency repair without removing the nail or screw that has punctured
the tread of the tire. If the object that has punctured the tire is removed, repair by the
emergency tire puncture repair kit may not be possible.
●The kit is not waterproof. Make sure that the kit is not exposed to water, such as when
it is being used in the rain.
●Do not put the kit directly onto dusty ground such as sand at the side of the road. If the
kit vacuums up dust etc., a malfunction may occur.
●Use the kit with the top facing upward. The kit cannot work properly if it is laid on its
side.
■Handling the emergency tire puncture repair kit
●The compressor power source should be 12 V DC suitable for vehicle use. Do not
connect the compressor to any other source.
●If gasoline splatters on the kit, the kit may deteriorate. Take care not to allow gasoline
to contact it.
●Store the kit in its assigned place out of reach of children.
●Do not disassemble or modify the kit. Do not subject parts such as the air pressure
indicator to impacts. This may cause a malfunction.
■To avoid damage to the tire pressure warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter may not operate properly. If a liquid sealant is used, contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional as soon
as possible. Make sure to replace the tire pressure warning valve and transmitter when
replacing the tire. (→P. 4 2 8 )

5308-2. Steps to take in an emergency
IS250_EE(OM53C51E)
CAUTION
■Avoiding battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flammable gas
that may be emitted from the battery:
●Make sure each jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any other than the intended terminal.
●Do not allow the other end of the jumper cable connected to the “+” terminal to come
into contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal.
●Do not allow the + and - clamps of the jumper cables to come into contact with each
other.
●Do not smoke, use matches, cigarette lighters or allow open flame near the battery.
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts
contain lead and lead compounds. Observe the following precautions when handling
the battery:
●When working with the battery, always wear safety glasses and take care not to allow
any battery fluids (acid) to come into contact with skin, clothing or the vehicle body.
●Do not lean over the battery.
●In the event that battery fluid comes into contact with the skin or eyes, immediately
wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be
received.
●Always wash your hands after handling the battery support, terminals, and other bat-
tery-related parts.
●Do not allow children near the battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in the
cooling fans or engine drive belt.

5409-1. Specifications
IS250_EE(OM53C51E)
Engine
Model4GR-FSE
Ty p e6-cylinder V type, 4-cycle, gasoline
Bore and stroke83.0 × 77.0 mm (3.27 × 3.03 in.)
Displacement2500 cm3 (152.6 cu. in.)
Va l v e c l e a r a n c e
(engine cold)Automatic adjustment
Drive belt tensionAutomatic adjustment
Fuel
Fuel type
EU area:
Unleaded gasoline conforming to European standard
EN228 only
Except EU area:
Unleaded gasoline only
Research Octane Number95 or higher
Fuel tank capacity
(Reference)66 L (17.4 gal., 14.5 Imp. gal.)

549
9 9-1. Specifications
Vehicle specifications
IS250_EE(OM53C51E)
■Fuel tank opening for unleaded gasoline
To help prevent incorrect fueling, your vehicle has a fuel tank opening that only accom-
modates the special nozzle on unleaded fuel pumps.
■If your engine knocks
●Consult any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
●You may occasionally notice light knocking for a short time while accelerating or driv-
ing uphill. This is normal and there is no need for concern.
Fuel information
EU area:
Your vehicle must use only unleaded gasoline conforming to European stan-
dard EN228.
For optimum engine performance, select unleaded gasoline with a Research
Octane Number of 95 or higher.
Except EU area:
Your vehicle must use only unleaded gasoline.
For optimum engine performance, select unleaded gasoline with a Research
Octane Number of 95 or higher.

5509-1. Specifications
IS250_EE(OM53C51E)
NOTICE
■Notice on fuel quality
●Do not use improper fuels. If improper fuels are used, the engine will be damaged.
●Do not use leaded gasoline.
Leaded gasoline will cause the three-way catalytic converter to lose its effectiveness
and the emission control system to function improperly.
●Gasoline engine (EU area): Bioethanol fuel sold under names such as “E50” or
“E85” and fuel containing a large amount of ethanol should not be used. The use of
these fuels will damage the vehicle’s fuel system. In case of any doubt, ask any autho-
rized Lexus dealer or repairer, or another duly qualified and equipped professional.
●Gasoline engine (except EU area): Bioethanol fuel sold under names such as “E50”
or “E85” and fuel containing a large amount of ethanol should not be used. Your vehi-
cle can use gasoline mixed with 10% max ethanol. The use of fuel with more than 10%
ethanol content (E10) will damage the vehicle’s fuel system. You must ensure that
refueling is carried out only from a source where fuel specification and quality can be
guaranteed. In case of any doubt, ask any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.