2006 Lexus GS430 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2005 PROD. OWNER'S MANUAL (OM30649U)

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556
The effectiveness of snow tires is lost if the tread
wears down below 4 mm (0.16 in.).
If you have tire damage such as cuts, splits, cracks
deep enough to expose the fabric, or bulges
indicating internal damage, the tire should be
replaced.
If a tire often goes flat or cannot be properly repaired due
to the size or location of a cut or other damage, it should
be replaced. If you are not sure, consult with your Lexus
dealer.
If air loss occurs while driving, do not continue driving.
Driving even a short distance can damage a tire beyond
repair.
Any tires which are over 6 years old must be
checked by a qualified technician even if damage is
not obvious.
Tires deteriorate with age even if they have never or
seldom been used.
This applies also to the spare tire and tires stored for
future use.NOTICE
 When you purchase new tires, consult your
Lexus dealer. If you change from runflat tires
to standard tires, a spare tire should also be
equipped.
 When the tires must be repaired or replaced,
have them repaired or replaced by Lexus dealer
or authorized dealer. The tire pressure sensors
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.

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557
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 500 and 542.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.

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558
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.

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559
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 sensor will
be affected by the installation or removal of snow
tires.
 When the snow tires must be replaced, replace the
grommets for tire pressure sensors 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 433.

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560
REPLACING WHEELS
As you might have difficulty in identifying a flat or deflated
tire, a tire pressure warning system is provided on this
vehicle.
When replacing the wheels, be sure to install tire pressure
sensors on the wheels.
There are 2 ways to set up the tire pressure sensors.
a. Remove the sensor from the old wheel and install it to the
new wheel.
b. Use a new wheel and sensor.You have to register an ID code for a new sensor. Up to 2
sets of codes can be registered. As one ID for the originally
installed sensor is registered at “MAIN” of the selector
switch, use the “2nd” position to register an ID for the new
sensor.
You do not need to re −register the ID code for any other
replacements. For the use of the originally installed tires,
put the selector switch at “MAIN” and for the use of tires
purchased later, put the switch at “2nd”. For the sensor
selector switch, see page 442.
CAUTION
 Have the tires, wheels or sensors replaced and ID
codes registered by Lexus dealer. If you need
sensors, purchase from Lexus dealer.
 The sensor nuts should always be tightened to a
torque of 4 N·m (0.4 kgf·m, 2.9 ft·lbf).
 The use of nongenuine wheels will cause the tire
pressure sensor to transmit the electronic code in
different manner, resulting in the failure of the
system.
When to replace your wheels
If you have wheel damage such as bending, cracks or
heavy corrosion, the wheel should be replaced.
If you fail to replace a damaged wheel, the tire may slip off the
wheel or cause loss of handling control.
Replacement with used wheels is not recommended as they
may have been subjected to rough treatment or high mileage
and could fail without warning. Also, bent wheels which have
been straightened may have hidden structural damage and
therefore should not be used. Never use an inner tube in a
leaking wheel which is designed for a tubeless tire.

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561
Wheel selection
When replacing wheels, care should be taken to ensure
that they are equivalent to those removed in load capacity,
diameter, rim width, and offset.
Correct replacement wheels are available at your Lexus
dealer.
A wheel of a different size or type may adversely affect
handling, wheel and bearing life, brake cooling,
speedometer/odometer calibration, stopping ability, headlight
aim, bumper height, vehicle ground clearance, and tire or snow
chain clearance to the body and chassis.
CAUTION
Observe the following instruction. Otherwise, an
accident may occur resulting in death or serious
injuries.
 Do not use wheels other than the manufacturer’s
recommended size, as this may cause dangerous
handling characteristics resulting in loss of control.
ALUMINUM WHEEL PRECAUTIONS
When installing aluminum wheels, check that the wheel
nuts are tight after driving your vehicle the first 1600 km
(1000 miles).
 If you have rotated, repaired, or changed your tires, check
that the wheel nuts are still tight after driving 1600 km (1000
miles).
 When using tire chains, be careful not to damage the
aluminum wheels.
 Use only Lexus wheel nuts and wrench designed for your
aluminum wheels.
 When balancing your wheels, use only Lexus balance
weights or equivalent and a plastic or rubber hammer.
 As with any wheel, periodically check your aluminum
wheels for damage. If damaged, replace immediately.

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562
SUSPENSION AND CHASSIS
CAUTION
Do not modify the suspension/chassis with lift kits,
spacers, springs, etc. It can cause dangerous handling
characteristics, resulting in loss of control.

SECTION 6 – 4
563
SERVICE PROCEDURES AND
SPECIFICATIONS
Electrical components
Specifications564
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Checking battery condition 571
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Battery recharging precautions 574
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Checking and replacing the blade type fuses 574
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Checking the cartridge type fuses 577
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Adding washer fluid 579
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Checking the headlight aim 579
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Replacing light bulbs 584
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