cooling Lexus IS250 2015 Owner's Manual

2394-5. Using the driving support systems
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Driving
IS350/250_U (OM53C50U)
■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. 358). 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.

3606-1. Using the air conditioning system
IS350/250_U (OM53C50U)
XWith a navigation system Adjust the left-hand side temper-
ature setting
Adjust the fan speed setting
Select the air flow mode
Adjust the right-hand side tem-
perature setting
Display the option control screen
(→ P. 360)
Tu r n t h e f a n o f f
Select to set auto mode on/off
To adjust or select settings, move the Remote Touch knob to select the screen
button, and then press the Remote Touch knob to enter the selected function.
■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) ( →P. 3 6 1 )
Removing pollen from the air
(Micro dust and pollen filter)
( → P. 3 6 1 )
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3646-1. Using the air conditioning system
IS350/250_U (OM53C50U)
■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.
■Using the voice command system (vehicles with a navigation system)
Air conditioning system can be operated us ing voice commands. For details, refer to the
“NAVIGATION SYSTEM OWNER’S MANUAL”.
■Fogging up of the windows
The windows will easily fog up when the hu midity 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 interi or. 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.
■When the outside temperature exceeds 75 °F (24 °C) and the air conditioning system
is on
●In order to reduce the air conditioning power consumption, the air conditioning system
may switch to recirculated air mode automatically. This may also reduce fuel consump-
tion.
●Recirculated air mode is selected as a default mode when the engine switch is turned to
IGNITION ON mode.
●It is possible to switch to outside air mode at any time by pressing .
■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

4107-3. Do-it-yourself maintenance
IS350/250_U (OM53C50U)
CAUTION
The engine compartment contains many mechan isms 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
●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.
■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 1 8 )
■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.

4137-3. Do-it-yourself maintenance
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Maintenance and care
IS350/250_U (OM53C50U)
Engine compartment
Fuse boxes (→P. 4 4 1 )
Battery ( →P. 4 2 0 )
Engine oil level dipstick (→ P. 4 1 4 )
Engine coolant reservoir (→ P. 4 1 7 )
Engine oil filler cap (→ P. 4 1 5 )Brake fluid reservoir (
→P. 4 1 9 )
Wa s h e r f l u i d t a n k ( →P. 422)
Electric cooling fans
Condenser ( →P. 4 1 8 )
Radiator ( →P. 4 1 8 )1
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4177-3. Do-it-yourself maintenance
7
Maintenance and care
IS350/250_U (OM53C50U)
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 0 6 )
■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.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deionized water.
(Minimum temperature: -31 °F [-35 °C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized water.
(Minimum temperature: -44 °F [-42 °C])
For more details about engine coolant, contact your Lexus dealer.
■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 your Lexus dealer test the cap and check for leaks in the
cooling system.
Engine coolant
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4187-3. Do-it-yourself maintenance
IS350/250_U (OM53C50U)
Check the radiator 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 your Lexus dealer.
CAUTION
■When the engine is hot
Do not remove the engine coolant reservoir cap or radiator cap. ( →P. 5 0 8 )
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.
Radiator and condenser
CAUTION
■When the engine is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

5058-2. Steps to take in an emergency
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When trouble arises
IS350/250_U (OM53C50U)
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.

5068-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
●The needle of the engine coolant temperature gauge (→P. 8 1 ) e n t e r s t h e r e d
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 your Lexus
dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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5078-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
The coolant level is satisfactory 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 emergency if
coolant is unavailable.
Start the engine and turn the air conditioning system on to check that the radi-
ator cooling fans operate and to check for coolant leaks from the radiator or
hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are 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 fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
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