2015 Lexus GS450h cooling

751-2. Hybrid system
GS450h_OM_OM30F70U_(U)
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For safety and security
■After the 12-volt battery has discharged or has been changed or removed
The gasoline engine may not stop even if the vehicle is running on the hybrid battery
(traction battery). If this continues for a few days, contact your Lexus dealer.
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sounds or vibration even though the vehicle is able to move.
For safety, apply the parking brake and make sure to shift the shift position to P when
parked.
The following sounds or vibrations may occur when the hybrid system is operating
and are not a malfunction:
●Motor sounds may be heard from the engine compartment.
●Sounds may be heard from the hybrid battery (traction battery) behind the rear
seats when the hybrid system starts or stops.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the hybrid tran smission when the hybrid system starts
or stops.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is
depressed.
●Vibration may be felt when the gasoline engine starts or stops.
●Cooling fan sounds may be heard from the ai r intake vents on the both sides of the
rear seatback.
■Vehicle proximity notification system
In the following cases, the vehicle proximity notification system may be difficult for
surrounding people to hear.
●In very noisy areas
●In the wind or the rain
Also, as the vehicle proximity notification system is installed on the front of the vehi-
cle, it may be more difficult to hear from the rear of the vehicle compared to the
front.
■Maintenance, repair, recycling, and disposal
Contact your Lexus dealer regarding main tenance, repair, recycling and disposal.
Do not dispose of the vehicle yourself.
■Customization
Settings (e.g. on/off operation of the EV indicator) can be changed.
(Customizable features: P. 5 9 9 )

771-2. Hybrid system
GS450h_OM_OM30F70U_(U)
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For safety and security
There are air intake vents on the
both sides of the rear seatback for
the purpose of cooling the hybrid
battery (traction battery). If the
vents become blocked, the hybrid
battery may overheat, leading to a
reduction in hybrid battery output.
When a certain level of impact is detected by the impact sensor, the emer-
gency shut off system blocks off the high voltage current and stops the fuel
pump to minimize the risk of electr ocution and fuel leakage. If the emer-
gency shut off system activates, your ve hicle will not restart. To restart the
hybrid system, contact your Lexus dealer.
A message is automatically displayed when a malfunction occurs in the
hybrid system or an improper operation is attempted.
If a warning message is shown on
the multi-information display, read
the message and follow the instruc-
tions.
( P. 513)
Hybrid battery (traction battery) air vents
Emergency shut off system
Hybrid warning message

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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. 335). 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 th e power switch is turned off after driving
in sport mode.

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4-6. Driving tips
Hybrid vehicle driving tips
◆Using Eco drive mode
When using Eco drive mode, the torque corresponding to the acceler-
ator pedal depression amount can be generated more smoothly than it
is in normal conditions. In addition, the operatio n of the air conditioning
system (heating/cooling) will be mini mized, improving the fuel econ-
omy. ( P. 280)
◆Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid
System Indicator within Eco area. ( P. 9 4 )
◆When braking the vehicle
Make sure to operate the brakes gently and in good time. A greater
amount of electrical energy can be retained when slowing down.
◆Delays
Repeated acceleration and decelerati on, as well as long waits at traffic
lights, will lead to bad fuel consumption. Check traffic reports before
leaving and avoid delays as much as possible. When encountering a
delay, gently release the brake pedal to allow the vehicle to move for-
ward slightly while avoiding overuse of the accelerator pedal. Doing so
can help control excessive gasoline consumption.
◆Highway driving
Control your speed and keep at a constant speed. Also, before stop-
ping at a toll booth or similar, allow plenty of time to release the acceler-
ator and gently apply the brakes. A greater amount of electrical energy
can be retained when slowing down.
For economical and ecological drivin g, pay attention to the following
points:

GS450h_OM_OM30F70U_(U)
3395-2. Using the air conditioning system and defogger
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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. 3 4 1 )
Vehicles with rear air conditioning system:
The temperature for the driver’s, fr ont passenger’s and rear seats
( P. 355) can be adjusted separately (3-ZONE mode) ( P. 3 4 1 )
Prevent ice from building up on the windshield and wiper blades
(if equipped) ( P. 361)
Remove pollen from the air (Micro dust and pollen filter) ( P. 3 4 9 )
Without rear air conditioning sys-
temWith rear air conditioning sys-
tem
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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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5-2. Using the air conditioning system and defogger
■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 power 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.
■Micro dust an d 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.
■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.

GS450h_OM_OM30F70U_(U)
3535-2. Using the air conditioning system and defogger
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Interior features
■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 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.
■Ventilation and air conditioning odors
●To let fresh air in, set the air conditioning system to the outside air mode.
●During use, various odors from inside an d outside the vehicle may enter into and
accumulate in the air condit ioning system. This may then cause odor to be emitted
from the vents.
●To reduce potential odors from occurring:
• It is recommended that the air conditio ning system be set to outside air mode
prior to turning the vehicle off.
• The start timing of the blower may be delayed for a short period of time immedi- ately after the air conditioning system is started in automatic mode.
■Air conditioning filter
 P. 4 5 8
■Customization
Settings (e.g. exhaust gas sensor sensitivity) can be changed.
(Customizable features: P. 5 9 9 )