2008 Lexus GS450h heating

32
1-1. Hybrid system
GS_HV_U
July 3, 2008 12:32 pm
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.

135
2-1. Driving procedures
2
When driving
GS_HV_U
May 13, 2008 3:11 pm
CAUTION
■When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, you may accidentally move the shift
lever or depress the accelerator pedal, which could cause an accident or fire due to
hybrid system overheating. Additionally, if the vehicle is parked in a poorly venti-
lated area, exhaust gases may collect and enter the vehicle, leading to death or a
serious health hazard.
■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 turning the hybrid system off. 
Each push on the brake pedal uses up th e reserve for the power-assisted brakes.
●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.

147
2-1. Driving procedures
2
When driving
GS_HV_U
May 13, 2008 3:11 pm
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.

151
2-2. Instrument cluster
2
When driving
GS_HV_U
December 12, 2007 3:50 pm
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. 5 3 8 )
■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.

204
2-4. Using other driving systems
GS_HV_U
January 4, 2008 10:02 am
■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 normal
about 10 minutes.
■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).
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 operating will exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping dist ance. 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.

370
3-7. Other interior features
GS_HV_U
December 13, 2007 10:51 am
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.
NOTICE
■To prevent damage to the seat heaters/ventilators
Do not put heavy objects on the seat and do not stick sharp objects (needles, nails,
etc.) into the seat.
■To prevent 12 volt battery discharge
Turn the switches off when the hybrid system is off.

5
When trouble arises
539
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
■Overheating
In the following situations, your vehicle may be overheating.
●The engine coolant temperature gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
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 necessary.
Water can be used in an emer-
gency measure if coolant is
unavailable. ( P. 5 4 8 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP6

585
Alphabetical index
GS_HV_U
December 12, 2007 3:50 pm
CareExterior ................................................... 402
Interior..................................................... 405
Seat belts ............................................... 406
Cargo capacity ....................................... 210
Cargo hooks ...........................................375
CD player/changer .............................257
Chains......................................................... 216
Child-protectors ....................................... 51
Child restraint system Definition....................................................113
Installation.................................................. 117
Installing CRS with lower 
anchors ................................................... 121
Installing CRS with seatbelts .......... 118
Installing CRS with top straps ....... 123
Child safety Airbag precautions ............................ 102
Battery precautions .............. 432, 537
Child restraint system .........................113
Child-protectors..................................... 51
How your child should wear 
the seatbelt ........................................... 69
Installing child restraints ..................... 117
Moon roof precautions ..................... 82
Power window lock switch .............. 77
Power window precautions.............79
Removed electronic key battery 
precautions ....................................... 455
Seat belt comfort guide......................67
Seat belt precautions.......................... 70
Seat heater precautions ................ 370
Trunk precautions .................................57
Cigarette lighter ....................................367 Cleaning
Exterior....................................................402
Interior .................................................... 405
Seat belts ............................................... 406
Clock ......................................................... 364
Coin holder .............................................360
Compass ................................................. 383
Condenser ..............................................428
Console box ........................................... 357
Cooling system Engine overheating.......................... 538
Cruise control Cruise control....................................... 166
Dynamic radar cruise control....... 169
Cup holders ............................................360
Curtain shield airbags............................ 95
Customizable features .......................569
Daytime running light system ........... 159
Defogger Rear window ........................................240
Side mirror.............................................240
Dimension................................................ 544
Dinghy towing ..........................................221
Display Energy flow .............................................. 27
Multi-information display ................ 155
Touch screen ....................................... 224
Trip information ................................... 156
Warning message ............................ 500
Do-it-yourself maintenance .............. 414
Door courtesy lights ............................352
Door pocket............................................. 361C
D