Page 600 of 670
CHASSIS
581
5. After completing the tire inflation pressure
measurement and adjustment, apply soapy water to
the valve and check for leakage.
6. Install the tire valve cap.
If a gauge and air pump are not available, have your
vehicle checked by your Lexus dealer.
CAUTION
Be sure to reinstall the tire valve caps. Without
the valve caps, dirt or moisture could get into
the valve core and cause air leakage. If the caps
have been lost, have new ones put on as soon
as possible.
NOTICE
Use only the original valve cap. If any othervalve cap is used, it may corrode or melt and
become difficult or impossible to remove.
Page 606 of 670

CHASSIS
587
Uniform tire quality grading
This information has been prepared in accordance
with regulations issued by the National Highway
Traffic Safety Administration of the U.S.
Department of Transportation. It provides the
purchasers and/or prospective purchasers of
Lexus vehicles with information on uniform tire
quality grading.
Your Lexus dealer will help answer any questions
you may have as you read this information.
DOT quality grades Ð All passenger car tires must
conform to Federal Safety Requirements in
addition to these grades. Quality grades can be
found where applicable on the tire sidewall
between tread shoulder and maximum section
width. For example: Treadwear 200 Traction AA
Temperature ATreadwear
Ð The treadwear grade is a comparative
rating based on the wear rate of the tire when tested
under controlled conditions on a specified government
test course. For example, a tire graded 150 would
wear one and a half (1 Ð 1/2) times as well on the
government course as a tire graded 100. The relative
performance of tires depends upon the actual
conditions of their use, however, and may depart
significantly from the norm due to variations in driving
habits, service practices and differences in road
characteristics and climate.
Traction AA, A, B, C Ð The traction grades, from
highest to lowest, are AA, A, B and C, and they
represent the tire's ability to stop on wet pavement
as measured under controlled conditions on specified
government test surfaces of asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is
based on braking (straight ahead) traction tests and
does not include cornering (turning) traction.
Page 611 of 670

CHASSIS
592
TYPES OF TIRES
Determine what kind of tires your vehicle is originally
equipped with.
1. Summer tires
Summer tires are high-speed capability tires best
suited to highway driving under dry conditions.
Since summer tires do not have the same traction
performance as snow tires, summer tires are
inadequate for driving on snow-covered or icy roads.
For driving on snow-covered or icy roads, we
recommend using snow tires. If installing snow tires,
be sure to replace all four tires.
2. All season tires
All season tires are designed to provide better traction
in snow and to be adequate for driving in most winter
conditions, as well as for use all year round.All season tires, however, do not have adequate
traction performance compared with snow tires in
heavy or loose snow. Also, all season tires fall short
in acceleration and handling performance compared
with summer tires in highway driving.
The details about how to distinguish summer tires
from all season tires are described on page 583.
CAUTION
Do not mix summer and all season tires on
your vehicle as this can cause dangerous
handling characteristics, resulting in loss of
control.
Do not use tires other than the manufacturer's
designated tires, and never mix tires or
wheels of the sizes different from the
originals.
Page 614 of 670

CHASSIS
595
This applies also to the spare tire and tires stored
for future use.
Tire selection
When replacing a tire, use a tire of the same size
and construction, and the same or greater load
capacity 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
Certification Label and sidewall of the tire, see pages
542 and 583.
CAUTION
Observe the following instructions. Otherwise,
an accident may occur resulting in death or
serious injuries.
Do not mix radial, bias belted, or bias-ply 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.
Do not use tires of different brands, sizes,
construction or tread patterns, as this may
cause dangerous handling characteristics
resulting in loss of control.
Page 615 of 670

CHASSIS
596
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 instructions. 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.
Do not use snow tires of different brands, sizes,
construction or tread patterns, 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 105 km/h (65 mph) with any type of
snow tires.
Page 620 of 670

CHASSIS
601
REPLACING WHEELS
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.
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 instructions. 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.
Do not use wheels of different brands, sizes and
types, as this may cause dangerous handling
characteristics resulting in loss of control.
Page 625 of 670
ELECTRICAL COMPONENTS
606
No.FUSEAMPERECIRCUIT
1SPARE10Spare fuse
2ALT140
Charging system and all
components in AM1º,
HEATERº, CDS FANº, FR
FOGº, DEFOGº, AIR SUSº,
AC115V INVº, SEAT HEATERº,
BATT CHGº, TOWING BRKº
and TOWINGº fuses
3SPARE15Spare fuse
4HEATER50Air conditioning system
5AIR
SUS50Rear height control air
suspension
6AM150
All components in ACCº, CIGº,
IG1º, FR WIP-WSHº, RR
WIPº, RR WSHº, DIFFº,
TEMSº and STAº fuses
7TOWING BRK30Trailer brake controller
8J/B50
All components in P FR P/Wº,
P RR P/Wº, D RR P/Wº, D
P/SEATº, P P/SEATº, TAILº,
PANELº and POWER OR
TI&TEº fuses
9BATTCHG30Trailer sub battery
10TOWING40Trailer lights
No.FUSEAMPERECIRCUIT
11CDS FAN20Electric cooling fan
12RR A/C30Rear air conditioning system
Page 629 of 670
ELECTRICAL COMPONENTS
610
48FR
WIP-WSH30Windshield wipers, windshield
washer
49TEMS20Electronic modulated
suspension
50DIFF20Four-wheel drive system
51RR WIP15Rear window wiper
52D P/SEAT30Driver's power seat
53P P/SEAT30Front passenger's power seat
54PWR
OUTLET15Power outlet (12 VDC)
55IG1 NO.210Rear air conditioning system,
inside rear view mirror, kinetic
dynamic suspension system
56RR WSH15Rear window washer
No.FUSEAMPERECIRCUIT
57ECU-IG10
Shift lock control system, power
windows, outside rear view
mirror defogger, anti-lock brake
system, active traction control
system, vehicle stability control
system, air conditioning system,
navigation system, power
windows, moon roof, Lexus Link
System, tilt and telescopic
steering, multi- information
display, driving position
memory system, rear view
monitor system, tire pressure
warning system