2006 Lexus GS430 suspension

OCCUPANT RESTRAINT SYSTEMS
156When 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
165
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
175
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 rails 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
339
STARTING AND DRIVING
Starting and driving
Three−way catalytic converters340
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine exhaust caution 341
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating the engine switch 342
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parking brake 352
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . .
Automatic transmission 353
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic throttle control system 364
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Intuitive parking assist 365
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear view monitor system 388
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cruise control 392
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . .
Dynamic radar cruise control 395
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adaptive variable suspension system 417
. . . . . . . . . . . . . . . . . . . . . . .
Traction control system 418
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle stability control system 420
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hill −start assist control system 422
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variable gear ratio steering system 424
. . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle dynamics integrated management 426
. . . . . . . . . . . . . . . . . . .
Brake system 427
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . .
Brake pad wear limit indicators 431
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric power steering system 432
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tire pressure warning system 433
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pre−collision system 443
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\

STARTING AND DRIVING
417
5Resuming the preset speed
If the preset speed is cancelled by pulling the control lever, by
depressing the brake pedal or vehicle stability control
activation, pushing the lever up in the “+ RES” direction will
restore the speed set prior to cancellation. However, once the
vehicle speed falls below about 40 km/h (25 mph), the preset
speed will not be resumed.
(c) Conventional cruise control mode failure warning
G13075
If the system malfunction is detected when the
conventional cruise control mode is in the ready mode or
operating, the master warning light comes on, a warning
tone sounds and the above message appears.
If this message appears, push the “ON− OFF” button to turn the
system off and then push it again to turn it on. If the setting still
cannot be made or the same message appears again, the
system might have malfunctioned. Although it is no problem
to continue driving, contact your Lexus dealer.
ADAPTIVE VARIABLE SUSPENSION SYSTEM (GS430 only)
G31041
 1Sport position 2Normal position
The adaptive variable suspension system controls
suspension and steering, and ensures optimum vehicle
posture and steering capabilities depending on the
driving condition.
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.

STARTING AND DRIVING
426
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. When the slip indicator light comes on, and the message
“CHECK ECB” appears on the multi
−information display, the
vehicle dynamics integrated management does not operate.
Have your vehicle checked by your Lexus dealer as soon as
possible.
In addition, when the master warning light comes on, and the
message “CHECK VGRS” or “CHECK P/S” appears on the
multi−information display, the system will not be temporarily
functioning. Although it is no problem in driving as usual, have
your vehicle checked by your Lexus dealer as soon as
possible.
CAUTION
Do not overestimate the vehicle dynamics integrated
management. Even when this management is
functional, there is a limit to vehicle stability, and
irresponsible driving may lead to an accident. When
driving, you should always pay attention to your speed
and keep a safe distance between your vehicle and the
vehicle in front.

STARTING AND DRIVING
435
CAUTION
If the low tire pressure warning light comes on, take
your vehicle to the nearest Lexus dealer or authorized
tire dealer or gas station as soon as possible, observing
the following instructions:
 Decelerate as soon as possible to the most
appropriate speed that conditions permit. Do not
drive over 90 km/h (55 mph).
 Avoid abrupt steering wheel maneuvering and
braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes,
causing death or serious injury.
 The warning system may not activate immediately if
bursts or sudden air leakage should occur.
When the tyre pressure warning system warning light is
lit, one or more of your tyres is significantly
underinflated. You should stop and check your tyres
as soon as possible, and inflate them to the proper
pressure as indicated on the vehicle’s tyre information
placard. Driving on a significantly underinflated tire
causes the tyre to overheat and can lead to tyre failure.
Underinflation also reduces fuel efficiency and tyre
tread life, and may affect the vehicle’s handling and
stopping ability. Each tyre, including the spare, should
be checked monthly when cold and set to the
recommended inflation pressure as specified in the
vehicle placard and owner’s manual.
NOTICE
 Do not use liquid sealants for a flat tire as tire
pressure sensors will be damaged.
 Take due care not to go over a curb stone and be
careful of the holes in the road because deflated tire
pressure affects tire cushion performance. The
wheels, tires, body, suspension and other
components could be damaged.
 Your ground clearance is reduced if the runflat tire
goes flat so avoid driving over obstacles and drive
slowly on rough, unpaved roads and speed bumps.
Also, do not attempt to go through an automatic car
wash as the vehicle may get caught, resulting in
damage.
 When the tires must be replaced, have them replaced
by the nearest Lexus dealer or authorized tire dealer.
The tire pressure sensor will be affected by the
installation or removal of tires.
 When the tires must be replaced, replace the
grommets for tire pressure sensors as well.

STARTING AND DRIVING
443
CAUTION
When the tires whose ID code is registered at “MAIN”
are used, the system does not work properly with the
selector switch set at “2nd”. If the tires whose ID code
is registered at “2nd” are stored nearby, the system will
detect their tire inflation pressure (and vice versa).
Liquid sealants for flat tires
NOTICE
Do not use liquid sealants for flat tires as the tire
pressure sensors will be damaged.
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.