stop LEXUS SC300 1999 Repair Manual

CHASSIS
367
Uniform tire quality grading
This information has been prepared in accordance with
regulations issued by the National Highway T raffic 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 ± All passenger vehicle tires must
conform to Federal Safety Requirements in addition to
these grades. These quality grades are molded on the
sidewall. Treadwear
± 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 ± 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 th eir 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 ± 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.
Temperature A, B, C ± The temperature grades are A (the
highest), B, and C, representing the tire's resistance to the
generation of heat and its ability to dissipate heat when tested
under controlled conditions on a specified indoor laboratory
test wheel. Sustained high temperature can cause the material
of the tire to degenerate and reduce tire life, and excessive
temperature can lead to sudden tire failure. The grade C
corresponds to a level of performance which all passenger car
tires must meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the minimum

CHASSIS
372
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 damaged wheels, a tire may slip off a
wheel or they may 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 rem oved 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.
ALUMINUM WHEEL PRECAUTIONS
After driving your vehicle the first 1600 km (1000 miles),
check that the wheel nuts are tight.
 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 the 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.

Engine compartment
ELECTRICAL COMPONENTS
377
No.FUSEAMPERECIRCUIT
1ENGINE7.5Charging system
2HTR10Air conditioning system, rear
window defogger
3WIPER20Windshield wipers and washer
4ST7.5
Starting system, cruise control
system, multiport fuel injection
system/sequential multiport fuel
injection system, instrument panel
lights
5IGN7.5
Discharge warning light, multiport
fuel injection system/sequential
multiport fuel injection system,
SRS airbag system
6PANEL7.5Instrument panel lights, glovebox
light
7MIR±HTR10Outside rear view mirror defogger
8TURN7.5Turn signal lights
9STOP15Stop lights, cruise control system
cancel device
10CIG15
Cigarette lighter, theft deterrent
system, shift lock system, SRS
airbag system, instrument panel
lights

ELECTRICAL COMPONENTS
400Parking lights
±±±±5E
Front side marker lights1943.8E
Front turn signal lights1157
NA27/8D
Rear turn signal lights115627D
Light BulbsBulbNo.WType
Stop lights115627D
Tail lights±±±±5E
Back±up lights115627D
High mounted stoplight92118E
License plate lights±±±±5E
Interior light±±±±10F
Personal lights±±±±8D
Glovebox light±±±±1.2E
Door courtesy lights±±±±5E
Footlights±±±±1.2E
Vanity lights±±±±3F
Trunk light1943.8E
A: HB4 halogen bulbs
B: HB3 halogen bulbs
C: H3 halogen bulbs
D: Single end bulbs
E: Wedge base bulbs
F: Double end bulbs