snow chains Lexus GS430 2006 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2006 PROD. OWNER'S MANUAL (OM30786U)

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
427
VEHICLE STABILITY CONTROLSYSTEM
The vehicle stability control system helps provide
comprehensive control of the systems such as antilock
brake system, traction control, engine control, etc. This
system automatically controls the brakes and engine to
help prevent the vehicle from skidding when cornering on
a slippery road surface or operating steering wheel
abruptly.
The vehicle stability control system is activated when the
vehicle speed is about more than 15 km/h (9 mph).
You may hear a sound in the engine compartment for a few
seconds just after the vehicle begins to move. This means that
the system is in the self− check mode, but does not indicate a
malfunction.
CAUTION
 Do not rely excessively on the vehicle stability
control system. Even if the vehicle stability control
system is operating, you must always drive carefully
and attentively to avoid serious injury. Reckless
driving will result in an accident. If the slip indicator
light blinks, sounding an alarm, special care should
be taken while driving.
 Only use tires of specified size. The size,
manufacturer, brand and tread pattern for all 4 tires
should be the same. If you use the tires other than
specified, or different type or size, the vehicle
stability control system may not function correctly.
When replacing the tires or wheels, contact your
Lexus dealer.
 In situations where the road surface is covered with
ice or snow, your vehicle should be fitted with snow
tires or tire chains.

STARTING AND DRIVING
435
The anti
−lock brake system becomes operative after the
vehicle has accelerated to a speed in excess of approximately
10 km/h (6 mph). It stops operating when the vehicle
decelerates to a speed below approximately 5 km/h (3 mph).
Depressing the brake pedal on slippery road surfaces such as
on a manhole cover, a steel plate at a construction site, joints
in a bridge, etc. on a rainy day tends to activate the anti −lock
brake system.
You may hear a click or motor sound in the engine
compartment for a few seconds when the engine is started or
just after the vehicle begins to move. This means that the
anti−lock brake system is in the self− check mode, and does not
indicate a malfunction.
When the antilock brake system is activated, the
following conditions may occur. They do not indicate a
malfunction of the system:
 You may hear the anti− lock brake system operating and feel
the brake pedal pulsating and the vibrations of the vehicle
body and steering wheel. You may also hear the motor
sound in the engine compartment even after the vehicle is
stopped.
 At the end of the anti−lock brake system activation, the
brake pedal may move a little forward.
CAUTION
Do not overestimate the antilock brake system:
Although the antilock brake system assists in
providing vehicle control, it is still important to drive
with all due care and maintain a moderate speed and
safe distance from the vehicle in front of you, because
there are limits to the vehicle stability and effectiveness
of steering wheel operation even with the antilock
brake system on.
If tire grip performance exceeds its capability, or if
hydroplaning occurs during high speed driving in the
rain, the antilock brake system does not provide
vehicle control.
Antilock brake system is not designed to shorten the
stopping distance: Always drive at a moderate speed
and maintain a safe distance from the vehicle in front of
you. Compared with vehicles without an antilock
brake system, your vehicle may require a longer
stopping distance in the following cases:
 Driving on rough, gravel or snowcovered roads.
 Driving with tire chains installed.
 Driving over the st eps such as the joints on the road.
 Driving on roads where the road surface is pitted or
has other differences in surface height.

STARTING AND DRIVING
444If the tire pressure warning light blinks...
G31048
If the tire pressure warning light blinks when the engine
switch “IGON” mode is selected, the tire pressure
warning system is not working properly.
The system will be disabled in the following conditions:
(When the condition becomes normal, the system will work
properly.)

If tires not equipped with tire pressure warning valves and
transmitters are used.
 If the ID code on the tire pressure warning valves and
transmitters is not registered.
 If electronic devices or facilities using similar radio wave
frequencies are nearby.
 If a radio set at similar frequencies is in use in the vehicle. 
If a window tint that affects the radio wave signals is
installed.
 If the tire pressure warning select switch is set to a dif ferent
tire setting.
 If there is a lot of snow or ice on the vehicle, in particular
around the wheels or wheel housings.
 If non− genuine Lexus wheels are used.
 If tire chains are used.
 If the tire inflation pressure is more than 500 kPa (5.1
kgf/cm
2 or bar, 73 psi).
If the tire pressure warning light blinks frequently when the
engine switch “IG −ON” mode is selected, have it checked by
your Lexus dealer.
Even if you use genuine wheels, the tire pressure warning
system may not work properly with some types of tires.
Pushing the tire pressure warning reset switch should not turn
off the tire pressure warning light.

DRIVING TIPS
459
Keep ice
and snow from accumulating under the fenders.
Ice and snow built up under your fenders can make steering
difficult. During bad winter driving, stop and check under the
fenders occasionally.
Depending on where you are driving, we recommend you
carry some emergency equipment.
Some of the things you might put in the vehicle are tire chains,
window scraper, bag of sand or salt, flares, small shovel,
jumper cables, etc.
DINGHY TOWING
G32001
Your vehicle is not designed to be dinghy towed (with four
wheels on the ground) behind a motorhome.
NOTICE
Do not tow your vehicle with four wheels on the ground.
This may cause serious damage to your vehicle.

SECTION 6 – 3
539
SERVICE PROCEDURES AND
SPECIFICATIONS
Chassis
Specifications (GS430)540
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications (GS300) 544
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking brake fluid 547
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
.
Checking tire inflation pressure 548
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tire information 551
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. . . . .
Run−flat tires 561
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . . .
Types of tires 562
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . . .
Rotating tires 563
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . . .
Checking and replacing tires 563
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing snow tires and chains 567
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing wheels 569
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . .
Aluminum wheel precautions 570
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Suspension and chassis 571
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHASSIS
564
The tires on your Lexus have built−in tread wear
indicators to help you know when the tires need
replacement. When the tread depth wears to 1.6 mm
(0.06 in.) or less, the indicators will appear. If you can
see the indicators in two or more adjacent grooves, the
tire should be replaced. Vehicles equipped with 245/40R18 93Y or
P245/40R18
93V tires: Your Lexus has been fitted with
specially developed tires which provide exceptional
dynamic performance under general road conditions.
However your riding comfort may worsen a little and
road noise may increase during driving. You may also
notice that your tires will wear more rapidly and tire grip
performance will be reduced on the snowy and/or icy
roads when compared to standard tires. Be sure to have
snow tires or tire chains on the snowy and/or icy roads
and drive carefully with the speed appropriate for road
conditions.
NOTICE
Low profile tire like 245/40R18 93Y or P245/40R18
93V may have greater damage than usual tires to
its tire wheel when receiving impact from the road
surface. Therefore, pay attention to the following.
 Be sure to use with proper tire inflation
pressure. If the tire inflation pressure is low, the
tire may have greater damage. For detailed
information about tire inflation pressure, see
page 542.
 Avoid driving onto high, sharpedged objects
and other road hazards. Failure to do so can
lead to severe tire damage.

CHASSIS
566
Tire selection
When replacing a tire, use a tire of the same size and
construction, and the same or greater maximum
load as the originally installed tires. Also, all the
tires must be the same brand and have the same
tread patterns.
Using any other size or type of tire may seriously affect
handling, ride, speedometer/odometer calibration,
ground clearance, and clearance between the body and
tires or snow chains.
Check that the maximum load of the replaced tire is
greater than 1/2 of the Gross Axle Weight Ratings
(GAWR) of either the front axle or the rear axle,
whichever is greater. As for the maximum load of the
tire, see the load limit at maximum cold tire inflation
pressure mentioned on the sidewall of the tire, and as for
the Gross Axle Weight Ratings (GAWR), see the
Certification Label. For details about the Certification
Label and sidewall of the tire, see pages 508 and 551.CAUTION
Observe the following instructions. Otherwise, an
accident may occur resulting in death or serious
injuries.
 Do not mix radial, bias belted, or biasply tires
on your vehicle, as this may cause dangerous
handling characteristics resulting in loss of
control.
 Do not use tires other than the manufacturer’s
recommended size, as this may cause
dangerous handling characteristics resulting in
loss of control.

CHASSIS
567
INSTALLING SNOW TIRES ANDCHAINS
When to use snow tires or chains
Snow tires or chains are recommended when driving on
snow or ice.
On wet or dry roads, conventional or radial tires provide better
traction than snow or studded tires.
Snow tire selection
If you need snow tires, select tires of the same size,
construction and load capacity as the originally installed
tires. Also, all the tires must be the same brand and have
the same tread patterns.
Do not use tires other than stated above. Since your vehicle
has radial tires as original equipment, make sure your snow
tires also have radial construction. Do not install studded tires
without first checking local regulations for possible restrictions.
CAUTION
Observe the following instruction. Otherwise, an
accident may occur resulting in death or serious
injuries.
Do not use snow tires other than the manufacturer’s
recommended size, as this may cause dangerous
handling characteristics resulting in loss of control.
Snow tire installation
Snow tires should be installed on all wheels.
Installing snow tires on the rear wheels only can lead to an
excessive difference in road grip capability between the front
and rear tires which could cause loss of vehicle control.
CAUTION
Do not drive with the snow tires incorrectly inflated.
 Never drive over 120 km/h (75 mph) with any type of
snow tires.
Tire chain selection
Regulations regarding the use of tire chains vary
according to location or type of road. Always check local
regulations before installing chains.
Use SAE Class ”S” type radial tire chains, with the exception
of radial cable chains or V− bar type chains.

CHASSIS
568
Chain installation
Install the chains on the rear tires as tightly as possible.
Do not use tire chains on the front tires. Retighten chains
after driving 0.5 1.0 km (1/4 1/2 mile).
When installing chains on your tires, carefully follow the
instructions of the chain manufacturer.
CAUTION
Do not exceed 50 km/h (30 mph) or the chain
manufacturer’s recommended speed limit,
whichever is lower.
 Drive carefully avoiding bumps, holes, and sharp
turns, which may cause the vehicle to bounce.
 Avoid sharp turns or lockedwheel braking, as use of
chains may adversely affect vehicle handling.
 When driving with chains installed, be sure to drive
carefully. Slow down before entering curves to avoid
losing control of the vehicle. Otherwise an accident
may occur.
NOTICE
When the snow tires must be repaired or replaced,
have them repaired or replaced by Lexus dealer or
authorized tire dealer. The tire pressure warning
valves and transmitters will be affected by the
installation or removal of snow tires.
 When the snow tires must be replaced, replace the
grommets for tire pressure warning valves and
transmitters as well.
 Do not attempt to use a tire chain on the compact
spare tire, as it may result in damage to the vehicle as
well as the tire.
If the chains are installed, the tire pressure warning
system may not operate properly. See “Tire pressure
warning system” on page 440.