2006 Lexus GS430 suspension

OCCUPANT RESTRAINT SYSTEMS
160When the seat belt pretensioners are activated, an operating
noise
may be heard and a small amount of non −toxic gas may
be released. This does not indicate that a fire is occurring. This
gas is normally harmless.
Once the seat belt pretensioners have been activated, the seat
belt retractors remain locked.
CAUTION
Do not modify, remove, strike or open the seat belt
pretensioner assemblies, airbag sensor or surrounding
area or wiring. Failure to follow these instructions may
prevent the seat belt pretensioners from activating
correctly, cause sudden operation of the system or
disable the system, which could result in death or
serious injury. Consult your Lexus dealer about any
repair and modification.
NOTICE
Do not perform any of the following changes without
consulting your Lexus dealer. Such changes can
interfere with proper operation of the seat belt
pretensioners in some cases.
 Installation of electronic devices such as a mobile
twoway radio, cassette tape player or CD player.
 Repairs on or near the seat belt retractor assemblies.
 Modification of the suspension system.
 Modification of the front end structure.
 Attachment of a grille guard (bull bar, kangaroo bar,
etc.), snowplow, winches or any other equipment to
the front end.
 Repairs made on or near the front fenders, front end
structure or console.

OCCUPANT RESTRAINT SYSTEMS
169
Do not attach any objects except Lexus genuine
parts in the area where the SRS knee airbag for the
front passenger will inflate. When using an ashtray
or auxiliary box on the front passenger’s console
box, be sure to keep it closed. The attached object, or
opened ashtray or auxiliary box might restrict
inflation of the airbag or be thrown away by the force
of the deploying airbag, causing a danger.
 Do not modify or remove any wiring. Do not modify,
remove, st rike or open any components, such as the
steering wheel pad, steering wheel, column cover,
dashboard near the front passenger airbag, front
passenger airbag cover, knee airbags or airbag
sensor assembly. Doing so may prevent the front
airbag system from activating correctly, cause
sudden activation of the system or disable the
system, which could result in death or serious injury.
Failure to follow these instructions can result in death
or serious injury. Consult your Lexus dealer about any
repair and modification.NOTICE
Do not perform any of the following changes without
consulting your Lexus dealer. Such changes can
interfere with proper operation of the SRS front airbag
system in some cases.
 Installation of electronic devices such as a mobile
twoway radio, cassette tape player or CD player.
 Modification of the suspension system.
 Modification of the front end structure.
 Attachment of a grille guard (bull bar, kangaroo bar,
etc.), snowplow, winches or any other equipment to
the front end.
 Repairs made on or near the front fenders, front end
structure, console, steering column, steering wheel,
lower portion of instrument panel or dashboard near
the front passenger airbag.

OCCUPANT RESTRAINT SYSTEMS
179
Do not use seat accessories which cover the parts
where the side airbags inflate. Such accessories may
prevent the side airbags from activating correctly,
causing death or serious injury.
 Do not modify or replace the front (and outboard rear)
seats or upholstery of the seats with front (and rear)
side airbags. Such changes may prevent the side
airbag system from activating correctly, disable the
system or cause the side airbags to inflate
accidentally, resulting in death or serious injury.
 Do not disassemble or repair the front and rear pillars
and roof side rail containing the curtain shield
airbags. Such changes may disable the system or
cause the curtain shield airbags to inflate
accidentally, resulting in death or serious injury.
Failure to follow these instructions can result in death
or serious injury. Consult your Lexus dealer about any
repair and modification.NOTICE
Do not perform any of the following changes without
consulting your Lexus dealer. Such changes can
interfere with proper operation of the SRS side airbag
and curtain shield airbag system in some cases.
 Installation of electronic devices such as a mobile
twoway radio, cassette tape player or CD player.
 Modification of the suspension system.
 Modification of the structure of the passenger
compartment.
 Repairs made on or near the console, front (or
outboard rear) seats .

SECTION 3 – 1
345
STARTING AND DRIVING
Starting and driving
Three−way catalytic converters346
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Engine exhaust caution 347
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Operating the engine switch 348
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Parking brake 358
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Automatic transmission 359
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Electronic throttle control system 371
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Intuitive parking assist 372
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Rear view monitor system 395
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Cruise control 398
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Dynamic radar cruise control 401
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Adaptive variable suspension system 424
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Traction control system 424
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Vehicle stability control system 427
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Hill −start assist control system 429
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Variable gear ratio steering system 431
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Vehicle dynamics integrated management 432
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Brake system 433
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Brake pad wear limit indicators 438
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Electric power steering system 438
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Tire pressure warning system 440
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Pre−collision system 449
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STARTING AND DRIVING
424
ADAPTIVE VARIABLE SUSPENSIONSYSTEM (GS430 only)
G31041
 1Sport position 2Normal position
The adaptive variable suspension system controls the
suspension according to the road and driving conditions.
Selecting an optimum driving mode allows good vehicle
posture and steering wheel operation in conjunction with
variable gear ratio steering system and electric power
steering system.
Sport mode: Suitable for sporty type driving, such as on
winding mountain roads and high speed driving.
Normal mode: Suitable for ordinary driving.
To turn on the sport mode, push the selector switch on the
“SPORT” side. The indicator comes on in the instrument
cluster.
To change to the normal mode, push the switch to the “NORM”
side.
TRACTION CONTROL SYSTEM
The traction control system automatically helps prevent
the spinning of drive wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the engine switch is selected in “IG −ON” mode, the
system automatically turns on.
CAUTION
Under certain slippery road conditions, full traction of
the vehicle and power against drive wheels cannot be
maintained, even though the traction control system is
in operation. Do not drive the vehicle under any speed
or maneuvering conditions which may cause the
vehicle to lose traction control. In situations where the
road surface is covered with ice or snow, your vehicle
should be fitted with snow tires or tire chains. Always
drive at an appropriate and cautious speed for the
present road conditions.

STARTING AND DRIVING
432
Variable gear ratio steering system failure
warning
G31044
If there is any malfunction in the system, the above message
appears and the master warning light comes on.
If the warning message and light come on while driving, the
system is not working. Although conventional steering
operates when maneuvered, a larger degree of wheel
maneuvering (than at the time when the system is functioning
properly) is needed when driving at low speed. At this time, the
center position of the steering wheel could be changed.
Although it is no problem to continue driving, have your vehicle
repaired at your Lexus dealer.
VEHICLE DYNAMICS
INTEGRATED MANAGEMENT (GS430 only)
Vehicle Dynamics Integrated Management (VDIM) helps
manage control for vehicle stability control system,
antilock brake system, brake assist system, traction
control system, engine output control, hillstart assist
control system and also manages variable gear ratio
steering system and electric power steering system.
In order to control sudden steering wheel operation and
the sideslip on slippery road surfaces, this system
provides excellent vehicle stability by automatically
controlling the brake, engine output and front wheel
angle.
The state of the tires will affect the performance of the vehicle
dynamics integrated management system. Be sure to check
the following:
 Are tires of specified size installed?
 Are tires of identical type installed?
 Do the tires have stipulated tire pressure?
 Are the tires worn?
A problem with the tires or modified suspension systems will
have an adverse effect on the system and may cause a
malfunction, so be careful.

STARTING AND DRIVING
449
If the tire pressure select switch is set to the wrong tire setting,
the system will not work properly. After about 1 hour, the tire
pressure
warning light blinks to indicate a system malfunction.
PRECOLLISION SYSTEM
(Vehicles with dynamic radar cruise control)
When the precollision system detects what it perceives
to be an unavoidable collision, the front seat belts are
quickly drawn back by the retractors (precollision seat
belts) and more powerful braking is applied according to
the amount of pedal depression to help reduce injury to
the occupants and damage to the vehicle body. In
addition, the adaptive variable suspension works to help
regulate the vehicle not to pitch forward so much.
The pre−collision system will operate when the engine switch
is selected in “IG −ON” mode.

STARTING AND DRIVING
452
Adaptive variable suspension control (GS430
only)
When the precollision sensor detects an object or
vehicle with which your vehicle may collide, and
determines that a collision may be unavoidable, the
adaptive variable suspension adjusts the damping effect
on the shock absorbers and regulates the vehicle not to
pitch forward so much.
The adaptive variable suspension will operate when the
following all conditions are met.
When the vehicle speed is about 5 km/h (3 mph) or over.
 When the approaching speed in regard to the object or the
vehicle exceeds about 30 km/h (18 mph).
Precollision system failure warning
G31079
Precollision system warning light
The light warns that there is a problem somewhere in the
precollision system.
The light comes on when the engine switch is selected in
“IG−ON” mode. If the system works properly, the light goes off
after a few seconds.
If the light does not come on when the engine switch is selected
in “IG−ON” mode, have your vehicle checked by your Lexus
dealer.
If the system has a problem, the pre− collision system warning
light comes on or blinks. At this time, the master warning light
comes on, a warning tone sounds, and either of the following
messages appears on the multi−information display.
 PCS DISABLED NOW
 CHECK PCS