2017 Lexus GS300h cooling

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1-2. Hybrid system
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GS450h_300h_OM_OM30F92E_(EE)
For safety and security
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration ev en though the vehicle is able to move with
the “READY” indicator is illuminated. For sa fety, apply the parking brake and make sure
to shift the shift lever to P when parked.
The following sounds or vibrations may occu r 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.
●Relay operating sounds such as a snap or so ft clank will be emitted from the hybrid bat-
tery (traction battery), behind the rear se ats, when the hybrid system is started or
stopped.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the transmission when the gasoline engine starts or stops,
when driving at low speeds, or during idling.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is depressed
or as the accelerator pedal is released.
●Vibration may be felt when the gasoline engine starts or stops.
●Cooling fan sounds may be heard from the air intake vents on the both sides of the rear
seatback.
■Maintenance, repair, recycling, and disposal
Contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer regarding maintenance, repair, recy cling 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. 561)

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1-2. Hybrid system
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GS450h_300h_OM_OM30F92E_(EE)
For safety and security
There are air intake vents on the both
sides of the rear seatback for the pur-
pose of cooling the hybrid battery
(traction battery). If the vents become
blocked, the hybrid battery may over-
heat, leading to a reduction in hybrid
battery output.
When a certain level of impact is detected by the impact sensor, the emergency
shut off system blocks the high voltage current and stops the fuel pump to mini-
mize the risk of electrocution and fuel leakage. If the emergency shut off system
activates, your vehicle will not restart. To restart the hybrid system, contact any
authorized Lexus retailer or Lexus authorized repairer, or any reliable repa irer.
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 instructions. (  P. 466)
Hybrid battery (traction battery) air intake vents
Emergency shut off system
Hybrid warning message

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4-6. Driving tips
Driving
GS450h_300h_OM_OM30F92E_(EE)
Hybrid vehicle driving tips
◆Using Eco drive mode
When using Eco drive mode, the torque corresponding to the accelerator
pedal depression amount can be generated more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heating/
cooling) will be minimized, improving the fuel economy. ( P. 311)
◆Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid System
Indicator within Eco area. ( P. 108, 123)
◆Shift lever operation
Shift the shift lever to D when stopped at a traffic light, or driving in heavy traf-
fic etc. Shift the shift lever to P when parking. When using the N, there is no
positive effect on fuel consumption. In the N, the gasoline engine operates but
electricity cannot be generated. Also, when using the air conditioning system,
etc., the hybrid battery (traction battery) power is consumed.
◆Accelerator pedal/brake pedal operation ● Drive your vehicle smoothly. Avoid abrupt acceleration and deceleration.
Gradual acceleration and deceleration will make more effective use of the
electric motor (traction motor) without having to use gasoline engine
power.
● Avoid repeated acceleration. Repeated acceleration consumes hybrid bat-
tery (traction battery) power, resulting in poor fuel consumption. Battery
power can be restored by driving with the accelerator pedal slightly
released.
◆When braking
Make sure to operate the brakes gently and in a timely manner. A greater
amount of electrical energy can be regenerated when slowing down.
For economical and ecological driving, pay attention to the following points:

3485-2. Using the air conditio ning system and defogger
GS450h_300h_OM_OM30F92E_(EE)Adjust the left-hand side temperature setting
Select the air flow to the feet and operate the windshield defogger
Adjust the fan speed setting
Select the air flow mode
* (the front seats)
Function on/off indicators on the option control screen
Display the option control screen ( P. 349)
Adjust the right-hand side temperature setting
Fan speed mode selector for automatic mode
Adjust the temperature for the driver’s and front passenger’s seats separately
(DUAL mode) ( P. 347)
Set cooling and dehumidification function on/off
Select to set automatic mode on/off
Select the air flow mode *
(the left-hand side)
Select the air flow mode * (the right-hand side)
Display the rear air conditioning operation screen ( P. 350)
Adjust the temperature for the driver’s, front passenger’s and rear seats (  P. 358) separately (3-ZONE mode) ( P. 347)
To adjust or select settings, move the Remote Touch knob to select the screen
button, and then press the Remote Touch knob or the “ENTER” button of
Remote Touch to enter the selected function.
Control screen
Without rear air conditioning systemWith rear air conditioning system
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3505-2. Using the air conditio ning system and defogger
GS450h_300h_OM_OM30F92E_(EE)
■Side display (vehicles with 12.3-inch display)
Adjust the left-hand side temperature setting
Select the air flow mode (the front seats)
Adjust the fan speed setting
Adjust the right-hand side temperature setting
Adjust the temperature for the driver’s and front passenger’s seats separately
(DUAL mode) (P. 347)
Set cooling and dehumidification function on/off
Select to set automatic mode on/off
Select the air flow mode (the left-hand side)
Select the air flow mode (the right-hand side)
Adjust the temperature for the driver’s, front passenger’s and rear seats (  P. 358) separately (3-ZONE mode) ( P. 347)
■Rear air conditioning control screen (with rear air conditioning system)
Adjust the rear seat temperature
setting
Disabling the switches on the rear
armrest
Turn the fan off (rear seat)
Select to set automatic mode on/
off (rear seat)
Without rear air conditioning systemWith rear air conditioning system
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5-2. Using the air conditioning system and defogger
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Interior features
GS450h_300h_OM_OM30F92E_(EE)
■Outside/recirculated air mode
●When driving on dusty roads su ch 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.
■Automatic mode for air intake control
In automatic mode, the system detects exhaust gas and other pollutants and automati-
cally 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.
■Operation of the air conditioning system in Eco drive mode
In the 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 performanc e, perform the following operations:
●Adjust the fan speed
●Turn off Eco drive mode (P. 311)
■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 is low
The dehumidification function may not operate even when “A/C” on the option control
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 and outside the vehicle may enter into and accu-
mulate in the air conditioning system. This may then cause odor to be emitted from the
vents.
●To reduce potential odors from occurring:

4006-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
WARNING
The engine compartment contains many mech anisms 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
●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 co ntrol unit, 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. Fuel fumes are flamma-
ble.
●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 t he 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 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. 411)
■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 refillin g, it may indicate a serious problem.

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6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Engine compartment
GS450h
■12-volt battery P. 412
Engine oil level dipstick
( P. 406)
Engine coolant reservoir ( P. 409)
Engine oil filler cap ( P. 407)
Power control unit coolant
reservoir ( P. 409) Fuse box (
P. 437)
Washer fluid tank ( P. 411)
Electric cooling fans
Condenser ( P. 411)
Radiator ( P. 411)1
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