2014 Lexus IS250 cooling

2644-5. Using the driving support systems
IS250_EE(OM53C51E)
■Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air condi-
tioning system to enhance fuel efficiency (→P. 376). To improve air conditioning perfor-
mance, adjust the fan speed or turn off Eco drive mode.
■Sport mode automatic deactivation
Sport mode is automatically deactivated if the engine switch is turned off after driving in
sport mode.

3816-1. Using the air conditioning system
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Interior features
IS250_EE(OM53C51E)
■Option control screen
The functions can be switched on and off.
Cooling and dehumidification
function
Adjusting the temperature for
driver and passenger seats sepa-
rately (“DUAL” mode)
(if equipped) (→P. 3 8 1 )
Removing pollen from the air
(Pollen removal mode)
(→P. 3 8 2 )
Press , or select “AUTO” on the air conditioning control screen.
Adjust the temperature setting.
To stop the operation, press or select “OFF” on the air conditioning
control screen.
■Automatic mode indicator
If the fan speed setting or air flow modes are operated, the automatic mode
indicator goes off. However, automatic mode for functions other than that
operated are maintained.
■Adjusting the temperature for driver and passenger seats separately
(“DUAL” mode) (if equipped)
To turn on the “DUAL” mode, perform any of the following procedures:
●Press .
●Select “DUAL” on the option control screen.
●Adjust the passenger’s side temperature setting.
The indicator comes on when the “DUAL” mode is on.
While in “DUAL” mode, the temperature of the rear air outlets is set at the right-
hand side temperature setting.
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Using automatic mode
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3856-1. Using the air conditioning system
6
Interior features
IS250_EE(OM53C51E)
■Registering air conditioning settings to electronic keys (vehicles with driving position
memory)
●Unlocking the vehicle using an electronic key and turning the engine switch to IGNI-
TION ON mode will recall that key's registered air conditioning settings.
●When the engine switch is turned off, the current air conditioning settings will automat-
ically be registered to the electronic key that was used to unlock the vehicle.
●The system may not operate correctly if more than one electronic key is in the vicinity or
if the smart entry & start system is used to unlock a passenger door.
●The doors that can recall the air conditioning setting when unlocked using the smart
entry & start system can be changed.* For details, contact any authorized Lexus dealer
or repairer, or another duly qualified and equipped professional.
*: The doors that can recall the driving position memory are changed at the same time.
■Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and the ambi-
ent conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow immediately
after is pressed or “AUTO” is selected.
■Fogging up of the windows
The windows will easily fog up when the humidity in the vehicle is high. Turning
(“A/C”) on will dehumidify the air from the outlets and defog the windshield effectively.
●If you turn (“A/C”) off, the windows may fog up more easily.
●The windows may fog up if the recirculated air mode is used.
■Outside/recirculated air mode
●When driving on dusty roads such as tunnels or in heavy traffic, set the outside/recircu-
lated air mode button to the recirculated air mode. This is effective in preventing out-
side air from entering the vehicle interior. During cooling operation, setting the
recirculated air mode will also cool the vehicle interior effectively.
●Outside/recirculated air mode may automatically switch depending on the tempera-
ture setting or the inside temperature.
■Operation of the air conditioning system in Eco drive mode
In Eco drive mode, the air conditioning system is controlled as follows to prioritize fuel
efficiency:
●Engine speed and compressor operation controlled to restrict heating/cooling capac-
ity
●Fan speed restricted when automatic mode is selected
To improve air conditioning performance, perform the following operations:
●Adjust the fan speed
●Turn off Eco drive mode
■When the outside temperature falls to nearly 0°C (32°F)
The dehumidification function may not operate even when is pressed or “A/C” is
selected.

4147-3. Do-it-yourself maintenance
IS250_EE(OM53C51E)
CAUTION
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energized. To avoid death or serious injury, observe
the following precautions.
■When working on the engine compartment
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, 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 or the battery. Fuel and
battery fumes are flammable.
●Be extremely cautious when working on the battery. It contains poisonous and corro-
sive sulfuric acid.
●Take care because brake fluid can harm your 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 discomfort, consult a doctor.
■When working near the electric cooling fans or radiator grille
Be sure the engine switch is off.
With the engine switch in IGNITION ON mode, the electric cooling fans may auto-
matically start to run if the air conditioning is on and/or the coolant temperature is high.
(→P. 4 2 2 )
■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.

4177-3. Do-it-yourself maintenance
7
Maintenance and care
IS250_EE(OM53C51E)For right-hand drive vehicles:
The battery and the fuse box in front of the battery are located on the opposite side of the
engine compartment.
Engine compartment
Fuse boxes (→P. 4 4 5 )
Battery (→P. 422)
Engine oil level dipstick
(→P. 4 1 8 )
Engine coolant reservoir
(→P. 4 2 1 )
Engine oil filler cap (→P. 4 1 9 )Wa s h e r f l u i d t a n k (→P. 4 2 6 )
Electric cooling fans
Condenser (→P. 422)
Radiator (→P. 422)1
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4217-3. Do-it-yourself maintenance
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Maintenance and care
IS250_EE(OM53C51E)
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the engine 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. 5 3 1 )
■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 radiator, hoses, engine coolant reservoir cap, 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.
Engine coolant
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CAUTION
■When the engine is hot
Do not remove the engine coolant reservoir cap or radiator cap. (→P. 5 3 1 )
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.

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.

5318-2. Steps to take in an emergency
8
When trouble arises
IS250_EE(OM53C51E)
●The needle of the engine coolant temperature gauge (→P. 95) enters the red
zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●Steam comes out from under the hood.
Stop the vehicle in a safe place and turn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine 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 qualified and equipped profes-
sional.
The coolant level is satisfactory if it is
between the “FULL” and “LOW”
lines on the reservoir.
Reser voir
“FULL”
“LOW”
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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