2015 Lexus GS350 cooling

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GS350_OM_OM30E15U_(U)
4-5. Using the driving support systems
■Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air
conditioning system to enhance fuel efficiency ( P. 301). To improve air condition-
ing performance, adjust the fan sp eed or turn off Eco drive mode.
■Automatic operation of the seat heater during Eco drive mode
Eco drive mode controls the heating operation and fan speed of the air conditioning
system to enhance fuel efficiency. If the driving mode select switch is switched to Eco
drive mode in cold temperatures, the seat heater will be automatically operated to
assist heating performance.
■Sport mode automatic deactivation
Sport mode is automatically deactivated if the engine switch is turned off after driv-
ing in sport mode.

GS350_OM_OM30E15U_(U)
3055-2. Using the air conditioning system and defogger
5
Interior features
■Option control screen
Select on the operation screen to display the option control
screen. The functions can be switched on and off.
Select to set cooling and de humidification function on/off
Vehicles without rear air conditioning system:
The temperature for the driver’s an d front passenger’s seats can be
adjusted separately (DUAL mode) ( P. 307)
Vehicles with rear air conditioning system:
The temperature for the driver’s, fr ont passenger’s and rear seats
( P. 321) can be adjusted separately (3-ZONE mode) ( P. 307)
Prevent ice from building up on the windshield and wiper blades
(if equipped) ( P. 327)
Remove pollen from the air (Micro dust and pollen filter) ( P. 315)
Without rear air conditioning sys-
temWith rear air conditioning sys-
tem
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GS350_OM_OM30E15U_(U)
5-2. Using the air conditioning system and defogger
■Side display (if equipped)
Front seat air outlet selector
Fan speed control
Fan speed display
Left-hand front seat side temperature control
Left-hand front seat side temperature display
Right-hand front seat side temperature display
Right-hand front seat side temperature control
Cooling and dehumidification function on/off
Automatic mode
DUAL mode
Left-hand front seat side air outlet selector
Right-hand front seat side air outlet selector
3-ZONE mode
Without rear air conditioning sys-
temWith rear air conditioning sys-
tem
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GS350_OM_OM30E15U_(U)
5-2. Using the air conditioning system and defogger
■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 th e outlets and defog the windshield effec-
tively.
●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 tunn els or in heavy traffic, set the outside/
recirculated air mode button to the recirculated air mode. This is effective in pre-
venting outside air from entering the vehicl e interior. During cooling operation, set-
ting the recirculated air mode will also cool the vehicle interior effectively.
●Outside/recirculated air mode may automatically switch depending on the tem-
perature setting or the inside temperature.
■When the outside temperature exceeds 75°F (24°C) and the air conditioning sys-
tem 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 consumption.
●Recirculated air mode is selected as a default mode when the engine switch is
turned on.
●It is possible to switch to outside air mode at any time by pressing .
■Automatic mode for air intake control
In automatic mode, the system detects ex haust gas and other pollutants and auto-
matically switches between outside air and recirculated air modes.
When the dehumidification function is off, and the fan is operating, turning automatic
mode on will activate the dehumidification function.

GS350_OM_OM30E15U_(U)
3195-2. Using the air conditioning system and defogger
5
Interior features
■Micro dust and pollen filter
●In order to prevent the windshield from fogging up when the outside air is cold, the
following may occur:
• Outside air mode does not switch to (recirculated air) mode.
• The dehumidification function operates.
• The operation cancels after approximately 1 minute.
●In rainy weather, the windows may fog up. Press .
●In extremely humid weather, the windows may fog up.
●The pollens are filtered out even if the mi cro dust and pollen filter is turned off.
■Operation of the air conditioning system in Eco drive mode
In the Eco drive mode, the air conditioning system is controlled as follows to priori-
tize fuel efficiency:
●Engine speed and compressor operation co ntrolled to restrict heating/cooling
capacity
●Fan speed restricted when automatic mode is selected
To improve air conditioning performanc e, perform the following operations:
●Adjust the fan speed
●Turn off Eco drive mode
■When the S-FLOW mode operates
If air flows to the driver’s seat only, the temperature setting for the front passenger’s
seat is not displayed.
■When the outside temperature falls to nearly 32 F (0C)
The dehumidification function may not operate even when “A/C” on the option con-
trol screen is selected.

GS350_OM_OM30E15U_(U)
3936-3. Do-it-yourself maintenance
6
Maintenance and care
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, 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 driv-
ing 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
corrosive 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
automatically start to run if the air conditioning is on and/or the coolant tempera-
ture is high. ( P. 404)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from get-
ting 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.

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GS350_OM_OM30E15U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
Fuse boxes ( P. 4 2 9 )
Battery ( P. 4 0 6 )
Engine oil level dipstick (P. 399)
Engine coolant reservoir (P. 4 0 2 )
Engine oil filler cap ( P. 400) Brake fluid reservoir
(P. 405)
Washer fluid tank ( P. 409)
Electric cooling fans
Condenser ( P. 404)
Radiator ( P. 404)1
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GS350_OM_OM30E15U_(U)
6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir wh en 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 2 9 )
■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 caps, 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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