2007 Lexus GS450h heating

11
1-1. Hybrid system
1
Before driving
NOTICE
■Hybrid battery air vent
●Do not put foreign objects over the air vent. The hybrid battery (traction battery)
may overheat and be damaged.
●Clean the air vent regularly to prevent the hybrid battery (traction battery) from
overheating.
●Do not wet the air vent. It may cause a short circuit and damage the hybrid bat-
tery (traction battery).
●Do not load a large amount of water such as an aquarium into the vehicle. If water
spills over the hybrid battery (tractio n battery), the battery may be damaged.

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2-1. Driving procedures
2
When driving
CAUTION
■When taking a nap in the vehicle
Always turn the hybrid system off. 
Otherwise, you may accidentally move the shift lever or press the accelerator
pedal, which could cause an accident or fi re due to abnormal hybrid system over-
heating. Additionally, if the vehicle is park ed in a poorly ventilated area, exhaust
fumes may enter the vehicle and cause gas poisoning.
■When braking the vehicle
●When the brakes are wet, drive more cautiously. 
Braking distance increases when the brakes are wet, and may cause one side of
the vehicle to brake differently than the other side. Also the parking brake may
not securely hold the vehicle.
●If the brake actuator does not operate, do not follow other vehicles closely and
avoid downhill or sharp turns that require making. 
In this case, braking is still possible, but it will require more force on the pedal than
usual. Braking distance may also increase.
●Do not pump the brake pedal if the hybrid system is not operating. 
Each push on the pedal uses up yo ur reserved brake fluid pressure.
●The brake system consists of 3 individual hydraulic systems: if one of the systems
fails, the other will still operate. In this case, the brake pedal should be depressed
more firmly than usual and braking distance becomes longer. 
Do not drive your vehicle with only a single brake system. Have your brakes fixed
immediately.

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2-1. Driving procedures
2
When driving
Parking brake
NOTICE
■Before driving
Fully release the parking brake.
Driving the vehicle with the parking brake set will lead to brake components over-
heating, which may affect braking performance and increase brake wear.
Sets the parking brake* 
(Depressing the pedal again
releases the parking brake.)
*: Fully depress the parking
brake pedal with your left
foot while depressing the
brake pedal with your right
foot.
CanadaU.S.A.

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2-2. Instrument cluster
2
When driving
NOTICE
■To prevent damage to the engine and its components
The engine may be overheating if the engine coolant temperature gauge is in the
red zone (“H”). In this case, immediately stop the vehicle in a safe place. Check the
engine after it has cooled completely. (P. 475)
■To activate the light sensitivity function properly
Do not affix a sticker or window tint to the rear window glass, or put an object
behind the rear seat.

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2-4. Using other driving systems
2
When driving
■VGRS is disabled in the following situations
●During stopping or the steering wheel has been moved for a long time while
driving at lower speeds.
●After the hybrid system is restarted at less than -22°F (-30°C).
■Reduced effectiveness of EPS
The effectiveness of EPS is reduced to prevent the system from overheating when
there is frequent steering input over an extended period of time. The steering wheel
may feel heavy as a result. Should this occur, refrain from excessive steering input or
stop the vehicle and turn the hybrid system OFF. The system should return to nor-
mal within 10 minutes.
CAUTION
Any of the following conditions may result in an accident which could cause death or
serious injury:
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is op erating on the wet or slick roads
The ABS is not designed to shorten the ve hicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you in the following situations.
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven roads
■TRAC may not operate effectively when
Directional control and power may not be ac hievable while driving on slippery road
surfaces, even if the TRAC is operating. 
Do not drive the vehicle in conditions where stability and power may be lost.

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3-7. Other interior features
Seat heaters (if equipped)
■The seat heaters can be used when
The power switch is in “IG-ON” mode.
■When not in use
Set the dial to “0”. The indicator light turns off.
CAUTION
■Burns
●Use caution when seating the following persons in a seat with the seat heater on
to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the disabled
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drug s that induce sleep (sleeping drugs,
cold remedies, etc.)
●Do not cover the seat with anything when using the seat heater. 
Using the seat heater with a blanket or cushion increases the temperature of the
seat and may lead to overheating.
Heats the seats
The indicator light comes on. 
The higher the number, the
w
armer the seats become.

326
3-7. Other interior features
Seat heaters and ventilators (if equipped)
■The seat heaters and ventilators can be used when
The power switch is in “IG-ON” mode.
■When not in use
Set the dial to “0”. The indicator light turns off.
CAUTION
■Burns
●Use caution when seating the following persons in a seat with the seat heater on
to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the disabled
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drug s that induce sleep (sleeping drugs,
cold remedies, etc.)
●Do not cover the seat with anything when using the seat heater. 
Using the seat heater with a blanket or cushion increases the temperature of the
seat and may lead to overheating.
The seat heaters and ventilators heat the seats and maintain good airflow
by blowing air from the seats.
Heats the seats
The indicator light (red) comes
on. 
The higher the number, the
w
armer the seats become.
Blows air from the seats
The indicator light (green)
comes on. 
The higher the number, the
str
onger the airflow becomes.

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5-2. Steps to take in an emergency
■Overheating
In the following situations, your vehicle may be overheating.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
●The engine coolant temperatur e gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when in specting under the hood of your vehicle
●Keep hands and clothing away from the fan and engine drive belt while the hybrid
system is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot. 
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
Add coolant if required.
Water can be used in an emer -
gency measure if coolant is
una
vailable. ( P. 4 8 4 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos -
sible.
STEP6