wheel Lexus GS450h 2007 Using the hands-free system (for cellular phone) / LEXUS 2007 GS450H THROUGH JUNE 2006 PROD. (OM30727U) Owner's Guide

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2-4. Using other driving systems
2
When driving
NOTICE
■When using intuitive parking assist
In the following situations, the system may not function correctly due to a sensor
malfunction etc. Have the vehicle checked by your Lexus dealer.
• A beep does not sound when you turn the main switch ON.
• The intuitive parking assist operation display flashes, and a beep sound when
no obstacle has been detected.
• If the area around a sensor collides with something, or is subjected to strong impact.
• If the bumper collides with something.
• If the display shows continuously without a beep.
■When changing tires
If you install tires of a size other than that recommended by the manufacturer, the
system will be unable to correctly detect steering wheel movement. Always use tire
sizes recommended by the manufacturer.
■When washing the vehicle
When washing the vehicle using high pressure cleaning equipment, do not spray
water directly on the sensors. Subjecting the sensors to high pressure impact may
cause a malfunction.

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2-4. Using other driving systems
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When driving
AVS (Adaptive Variable Suspension System)
AVS controls the suspension according to the road and driving conditions.
Selecting an optimum driving mode allows good vehicle posture and steer
-
ing wheel operation in conjunction with VGRS, EPS and active stabilizer
s
uspension system.
Sports mode
For winding mountain road driv -
ing or high speed driving.
Normal mode
For normal driving.

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2-4. Using other driving systems
Driving assist systems
To help enhance driving safety and performance, the following systems
operate automatically in response to various driving situations. Be aware,
however, that these systems are supplementary and should not be relied
upon too heavily when operating the vehicle.
■ABS (Anti-lock Brake System)
Restrains the vehicle from slipping when driving on slick road surfaces or
in the event of sudden braking.
■BA (Brake Assist)
Generates an increased level of braking force after the brake pedal is
depressed, when the system detects a panic stop situation.
■VSC (Vehicle Stability Control)
Helps the driver to control skidding wh en swerving suddenly or turning on
slippery road surfaces.
■ TRAC (Traction Control)
Maintains drive power and prevents the rear wheels from spinning when
starting the vehicle or accelerating on slippery roads.
■Hill-start assist control
Helps prevent the vehicle from rolling backwards when starting on an
incline or slippery slope. It operat es for approximately 5 seconds at maxi -
mum.
■ VGRS (Variable Gear Ratio Steering)
Adjusts the wheel turning angle in accordance with the vehicle speed and
steering wheel movement.
■EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.
■Active stabilizer suspension system
Turns at smaller angles to main tain the stable vehicle posture.

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2-4. Using other driving systems
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When driving
When the VSC/TRAC/hill-start assist control systems are operating
If the vehicle is in danger of slip-
ping, rolling backwards when
star
ting on an incli ne, or if the rear
wheels spin, the slip indicator light
flashes to indicate that the VSC/
TRAC/hill-start assist control sys -
tems have been engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
The stop lights and high mounted
stoplight turn on when the hill-star
t
assist control system is operating.
The slip indicator light flashes as
well when ABS is operating.
■ VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the AB S, VSC, TRAC, hill-start assist con-
trol, VGRS and EPS systems. 
Maintains vehicle stability when swerving on slippery road surfaces by
contr
olling the brakes, engine output, and the movement of the front
wheels.
■ PCS (Pre-Collision System) (if equipped)
 P. 1 6 7

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2-4. Using other driving systems
To disable TRAC
If the vehicle gets stuck in fresh snow or mud, TRAC may reduce power
from the engine to the wheels. You may need to turn the system off to
enable you to rock the vehicle in order to free it.
Push the button to turn off TRAC.
The slip indicator light should come
on.
Push the button again to turn the
sy
stem back on.
Once you turn the power switch
“
OFF”, TRAC will be activated
automatically.
■Automatic TRAC reactivation
TRAC is reactivated when vehicle speed exceeds 30 mph (50 km/h) even if
“

TRAC OFF” has been turned off.
■Sounds and vibrations caused by the ABS, BA, VSC, TRAC, hill-start assist con-
trol and VGRS systems
●A sound may be heard from the engine compartment when the hybrid system is
started or just after the vehicle begins to move. This sound does not indicate that
a malfunction has occurred in any of these systems.
●Any of the following conditions may occur when the above systems are operat -
ing. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly af
ter the ABS is activated.
■Hill-start assist control is operational when
●The shift lever is in the “D” or “S” position.
●The brake pedal is not depressed.

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2-4. Using other driving systems
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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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2-4. Using other driving systems
CAUTION
■The hill-start assist control may not operate effectively when
●On steep inclines.
●On icy surfaces.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
■Replacing tires
Make sure that all tires are of the same size, brand, tread pattern and total load
capacity. In addition, make sure that the ti res are inflated to the specified tire pres-
sure level.
The ABS and VSC will not function correctly if different tires are fitted on the vehi-
cle. 
Contact your Lexus dealer for further info rmation when replacing tires or wheels.
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the
VDIM, and may cause the system to malfunction.

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2-5. Driving information
2
When driving
■Before driving the vehicle
Perform the following according to the driving conditions.
● D
o not try to forcibly open a w indow or move a wiper that is fro-
zen. Pour warm water over the frozen ar
ea to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● T
o ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
● R
emove any ice that has accumul ated on the vehicle chassis.
● P
eriodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.
■ When driving the v
ehicle
Accelerate the vehicle slowly and dr iv
e at a reduced speed suitable
to road conditions.
■ When parking the v
ehicle
Park the vehicle and move the shift lever to “P” without setting the
parking br
ake. The parking brake ma y freeze up, preventing it from
being released.

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2-5. Driving information
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When driving
To retract positionLower the wipers by pressing on
the upper par
t of the hook section.
■Snow chain installation
Observe the following precautions when installing and removing chains.
●Install and remove tire chains in a safe location.
●Install tire chains on the rear tires.
●Install tire chains following the inst ructions provided in the accompanying
instructions.
CAUTION
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents. 
Failing to do so may result in a loss of vehicle control and cause death or serious
injury.
●Use tires of the size specified for your vehicle.
●Maintain the specified level of tire inflation pressure.
●Do not drive in excess of 75 mph (120 km/h), regardless of the type of snow tires
being used.
●Snow tires should be installed on all wheels.

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2-5. Driving information
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When driving
Trailer towing
Lexus does not recommend towing a trailer with your vehicle. Lexus also
does not recommend the installation of a tow hitch or the use of a tow hitch
carrier for a wheelchair, scooter, bicycle, etc. Your Lexus is not designed
for trailer towing or for the us e of tow hitch mounted carriers.