2013 Lexus GS450h cooling

731-2. Hybrid system
GS450h_U (OM30D01U)
1
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. 8 0 7 )

751-2. Hybrid system
GS450h_U (OM30D01U)
1
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. 721)
Hybrid battery (traction battery) air vents
Emergency shut off system
Hybrid warning message

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GS450h_U (OM30D01U)
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. 364). 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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GS450h_U (OM30D01U)4-6. Driving tips
4
Driving
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. 2 8 6 )
■Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid
System Indicator within Eco area. ( P. 9 2 )
■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_U (OM30D01U)
3675-2. Using the air conditioning system and defogger
5
Interior features
Fan speed control
Air flows to the feet and the
windshield defogger operates.
Outside temperature
Right-hand front seat side tem-
perature control
Right-hand front seat side tem-
perature display
Front seat air outlet selector
Micro dust and pollen filter
DUAL/3-ZONE mode
Cooling and dehumidification
function on/off
Left-hand front seat side tem-
perature display Left-hand front seat side tem-
perature control
Windshield defogger
Outside air or recirculated
mode
Air outlet selector
S-FLOW mode
Off
Automatic mode
Left-hand front seat side air out-
let selector
Rear air conditioning operation
screen
Right-hand front seat side air
outlet selector1
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GS450h_U (OM30D01U)
5-2. Using the air conditioning system and defogger
■Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and the
ambient conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow immedi-
ately after is pressed.
■Humidity sensor
■Fogging up of the windows
●The windows will easily fog up when the humidity in the vehicle is high. Selecting
on will dehumidify the air from the outlets and defog the windshield effec-
tively.
●If you turn 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.
A sensor, which detects humidity inside the
vehicle and the temperature of the wind-
shield, is provided to detect fog on the front
windscreen. Due to the sensor, when auto-
matic mode is set the air conditioning may
make the following controls:
●Changing the amount of air flow
●Changing the amount of air introduced from
outside when in outside air mode with the air
vents in the position
●Changing the settings of the air vents to
when the is set

GS450h_U (OM30D01U)
3775-2. Using the air conditioning system and defogger
5
Interior features
■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.
■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 is selected.

GS450h_U (OM30D01U)
6336-3. 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
●Make sure that the “POWER ON” on the multi-information display and the
“READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, power control unit, radiator, exhaust manifold,
etc. right after driving as they may be hot. Oil and ot her 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. Fuel fumes are flam-
mable.
■When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fans may automatically
start to run if the air conditioning is on and/or the coolant temperature is high.
(  P. 6 4 4 )
■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. Also, a backfire could cause a fire in the engine compartment.