2004 Lexus GX470 traction control

STARTING AND DRIVING
390Depressing the brake pedal repeatedly may turn on the light.
It is normal if it goes out after a few seconds.
The brake actuator temperature increases during continuous
operation of the above mentioned systems such as on slippery
roads. If the brake actuator temperature becomes too high
while any of the systems is operating, a buzzer will start to
sound intermittently to indicate that the active traction control
system can no longer operate. In this case, immediately stop
your vehicle at a safe place.
If the system continues to operate, the buzzer sound changes
from intermittent to continuous. (The continuous buzzer
sounds for about 3 seconds.) At the time, the VSC TRACº
warning light will come on and the active traction control
system temporarily stops operating in order to protect the
brake actuator. (Although the active traction control system
does not operate, there is no problem to continue your driving.)
The system will be automatically restored after a short time and
the VSC TRACº warning light goes out.
If the light comes on while driving, the active traction control
system does not work. However, as normal braking operates
when being applied, there is no problem to continue your
driving.
In the following cases, contact your Lexus dealer:
The warning light does not come on after the ignition key is
turned to ONº.
The warning light remains on after the ignition key is turned
to ONº.
The warning light comes on while driving.
VEHICLE STABILITY CONTROL
SYSTEM
The vehicle stability control system helps provide
integrated control of the systems such as anti-lock brake
system, traction control, engine control, etc. This system
automatically controls the output of the brakes or engine
to help prevent the vehicle from skidding when cornering
on a slippery road surface or operating steering wheel
abruptly.
The system activates when the vehicle speed about more than
15 km/h (9mph).
You may hear a 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 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 unexpected accident. If the
slip indicator light blinks and an alarm sounds,
special care should be taken while driving.

STARTING AND DRIVING
392The indicator light comes on when the system is on while
driving.
NOTICE
Make sure that the center differential lock indicator light
goes off before normal driving.
VSC TRACº warning light
This light warns that when there is a problem somewhere in the
following.
Vehicle stability control system
Active traction control system
Downhill assist control system
Hill-start assist control systemWhen the system is normal and the ignition key is turned to
ONº, the warning light will come on and will go off after a few
seconds. It is not a malfunction that the warning light may stay
on for 60 seconds after the ignition key is turned to the ONº
position.
Depressing the brake pedal repeatedly may turn on the light.
It is normal if they go out after a few seconds.
If the light comes on while driving, the vehicle stability control
system does not work. However, as normal braking operates
when being applied, there is no problem to continue your
driving.
In the following cases, contact your Lexus dealer:
The warning light does not come on after the ignition key is
turned to ONº.
The warning light remains on after the ignition key is turned
to ONº.
The warning light comes on while driving.

STARTING AND DRIVING
394If the indicator light does not come on when the switch is
pushed, contact your Lexus dealer.

Slip indicator light
With the vehicle traveling at a speed of 25 km/h (15 mph) or
less, release your foot from the accelerator or brake pedal to
activate the system. The vehicle will descend the hill at a low
speed. While the system is operating, the slip indicator light on
the instrument panel will flash and the stop lights and high
mounted stoplight will be lit.
If you push the DACº switch to turn the system off while it is
in operation, the system will stop operating gradually. The
downhill assist control system indicator light will flash to alert
the driver. To continue driving at a low speed, push the DACº
switch to turn the system on.
The slip indicator light and downhill assist control system
indicator light come on for a few seconds when the ignition key
is turned to ONº. If any of the indicator lights does not come
on when the ignition is turned on, contact your Lexus dealer.If the system is used frequently, the brake actuator
temperature may become too high and a buzzer will sound
intermittently.
If this happens, the downhill assist control system indicator
light will flash and a buzzer will sound intermittently. When the
temperature of the brake actuator goes down, the system will
begin to operate again. Until it restarts, the active traction
control system and hill-start assist control system will not
operate; however, the conventional brake can be operated.

STARTING AND DRIVING
395
VSC TRACº warning light
If there is any abnormality in the system, the VSC TRACº
warning light will come on. When the DACº switch is
pushed, the downhill assist control system indicator light
also flash.
If the VSC TRACº warning light comes on, there may be an
abnormality in any of the following systems in addition to the
downhill assist control system.
Hill-start assist control system
Active traction control system
Vehicle stability control system
When the system is normal and the ignition key is turned to
ONº, the warning light will come on and will go off after a few
seconds. It is not a malfunction that the warning light may stay
on for 60 seconds after the ignition key is turned to the ONº
position.Depressing the brake pedal repeatedly may turn on the light.
It is normal if it goes out after a few seconds.
The brake actuator temperature increases during continuous
operation of the above mentioned system on such as slippery
roads. If the brake actuator temperature becomes too high
while any of the systems is operating, a buzzer will start to
sound intermittently to indicate that the downhill assist control
system can no longer operate. In this case, stop your vehicle
immediately at a safe place.
If the system continues to operate, the buzzer sound changes
from intermittent to continuous. (The continuous buzzer
sounds for about 3 seconds.) At this time, the VSC TRACº
warning light will come on and the downhill assist control
system stops operating temporarily in order to protect the
brake actuator. (Although the downhill assist control system
does not operate, it is no problem to continue your driving.) The
system will be automatically restored after a short time and the
VSC TRACº warning light goes out.
If the warning light comes on while driving, the system does not
work. However, as normal braking operates when being
applied, it is no problem to continue your driving.
In the following cases, contact your Lexus dealer:
The warning light does not come on after the ignition key is
turned to ONº.
The warning light remains on after the ignition key is turned
to ONº.
The warning light comes on while driving.

STARTING AND DRIVING
397 The slip indicator light comes on for a few seconds when the
ignition key is turned to ONº. If the indicator light does not
come on when the ignition is turned on, contact your Lexus
dealer.
Keep in mind the following when driving.
The hill-start assist control system operates for 5 seconds
maximally. If both the brake and accelerator pedals remain
undepressed for longer than 5 seconds, the buzzer will
sound at more frequent intervals and the system will
gradually stop operating.
The hill-start assist control system is not designed as a
function for stopping the vehicle on a uphill slope. When
stopping the vehicle, be sure to depress the brake pedal.
If the system is used frequently, the brake actuator
temperature may become too high and a buzzer will sound
intermittently.
In this case, a buzzer will sound intermittently. When the
temperature of the brake actuator goes down, the system will
begin to operate again. Until it restarts, the active traction
control system and downhill assist control system will not
operate; however, the conventional brake can be operated.
VSC TRACº warning light
If there is any abnormality in the system, the VSC TRACº
warning light will come on.
If the system malfunctions, the VSC TRACº warning light will
come on.
If the VSC TRACº warning light comes on, there may be an
abnormality in any of the following systems in addition to the
hill-start assist control system.
Downhill assist control system
Active traction control system
Vehicle stability control system
When the system is normal and the ignition key is turned to
ONº, the warning light will come on and will go off after a few
seconds. It is not a malfunction that the warning light may stay
on for 60 seconds after the ignition key is turned to the ONº
position.

STARTING AND DRIVING
401 ABSº warning light
The light comes on when the ignition key is turned to the ONº
position. If the anti-lock brake system and the brake assist
system work properly, the light turns off after a few seconds.
Thereafter, if either of the systems malfunctions, the light
comes on again.
When the ABSº warning light is on (and the brake system
warning light is off), the anti-lock brake system, the brake
assist system, the active traction control system and the
vehicle stability control system do/does not operate, but the
brake system still operates conventionally.
When the ABSº warning light is on (and the brake system
warning light is off), the anti-lock brake system does not
operate so that the wheels could lock up during a sudden
braking or braking on slippery road surfaces.If either of the following conditions occurs, this indicates
a malfunction somewhere in the components monitored
by the warning light system. Contact your Lexus dealer as
soon as possible to service the vehicle.
The light does not come on when the ignition key is turned
to the ONº position, or remains on.
The light comes on while you are driving.
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If the ABSº warning light remains on together with the
brake system warning light, immediately stop your
vehicle at a safe place and contact your Lexus dealer.
In this case, not only the anti-lock brake system will fail
but also the vehicle will become extremely unstable
during braking.
Either of the following conditions may occur, but do not
indicate a malfunction:
The light may stay on for about 60 seconds after the ignition
key is turned to the ONº position. It is normal if it turns off
after a while.
Depressing the brake pedal repeatedly may turn on the
light. It is normal if it turns off after a few seconds.

CHASSIS
539
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 A
Treadwear 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.
Temperature A, B, C Ð 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 required by
law.
Warning: The temperature grade for this tire
established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.

CHASSIS
543
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 535.
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.