traction control LEXUS LX470 2006 User Guide

STARTING AND DRIVING
288When your vehicle is loaded heavily or you are driving in an
unpaved
road, the mode
3
or 4 will be recommended. To
provide good vehicle stability, the damping effect will be harder
than for ordinary driving mode.
With the four−wheel drive control lever at “L”, the damping
effect suitable for off −road driving will be provided.ACTIVE TRACTION CONTROL
SYSTEM
31X518a
Active traction control system indicator light
The active traction control system automatically helps
control the spinning of 4 wheels which may occur when
accelerating on slippery road surfaces, by controlling the
output of the brake and engine. Thus, the system assists
driver to control the driving power of 4 wheels. When you
turn the ignition switch on, the active traction control
system always turns on automatically, and the active
traction control indicator light will come on. The indicator
light will go off after a few seconds.
When active traction control is applied, the active traction
control system indicator light blinks.

STARTING AND DRIVING
289
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 active traction control
system is in the self
−check mode, and does not indicate
malfunction. When the active traction control system is
operating, you may feel vibration or hear noise of your vehicle,
caused by operation of the brakes. This indicates the system
is functioning properly.
When getting the vehicle out of mud or newly fallen snow, etc.,
the active traction control system will help operate to prevent
the wheels from spinning.
31X503
 Active traction control system failure warning
This light warns when there is a problem somewhere in the
active traction control system or vehicle stability control
system.
If the “VSC/TRAC” warning light comes on, have your vehicle
checked by your Lexus dealer as soon as possible. The brake actuator temperature increases during the active
traction control system or vehicle stability control system
operating. If the brake actuator temperature becomes too high
while the active traction cont
rol system or vehicle stability
control system 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 sound will stop after about 3 seconds.) At
the time the “VSC/TRAC” 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 “VSC/TRAC” warning light goes
off if the accelerator pedal is released.
When the “ABS” warning light comes on, the active traction
control system is not operating.
The “VSC/TRAC” warning light will come on when the ignition
key is turned to “ON”, and will go off after a few seconds.
The “VSC/TRAC” warning light may stay on for 60 seconds
after the ignition key is turned to the “ON” position. It is normal
if it goes off after a few seconds.
Depressing the brake pedal repeatedly may turn on the
“VSC/TRAC” warning light. It is normal if it goes off after a few
seconds.
When the “VSC/TRAC” warning light comes on, the active
traction control system is not operating, but there is no problem
if you continue to drive.

STARTING AND DRIVING
290In the following cases, contact your Lexus dealer:

The “VSC/TRAC” warning light does not come on after the
ignition is turned to on.
 The “VSC/TRAC” remains on after the ignition is turned to
on.
CAUTION
Under certain slippery road conditions, full traction of
the vehicles and power to 4 wheels may not be
maintained, even though the active traction control
system is in operation. Do not drive the vehicle under
any speed or maneuvering conditions which will cause
the vehicle to lose traction. 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 road
conditions present.
VEHICLE STABILITY CONTROL SYSTEM
31X504
The vehicle stability control system helps provide
integrated control of the systems such as antilock
brakes, traction control, engine control, etc. This system
automatically controls the output of the brakes or engine
to help prevent the vehicle from skidding under adverse
conditions.
When you turn the ignition switch on, the slip indicator light will
come on. The slip indicator light will go off after a few seconds.
If the vehicle is going to skid during driving, the slip indicator
light flashes and an alarm sounds intermittently.

STARTING AND DRIVING
291
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 when the engine is started or just after the vehicle
begins to move. This means that the vehicle stability control
is in the self−
check mode and does not indicate a malfunction.
31X529
Pushing the center differential lock button automatically turns
the vehicle stability control system off. At this time, the “VSC
OFF” indicator comes on with the center differential lock
indicator light. (For details, see “Four −wheel drive system” on
page 266.)
31x505
 Vehicle stability control system failure warning
These lights warn when there is a problem somewhere in the
vehicle stability control system or active traction control
system.
If the “VSC/TRAC” warning light and “VSC OFF” indicator light
come on, have your vehicle checked by your Lexus dealer as
soon as possible. However, there is no problem even if the
“VSC/TRAC” warning light comes on when the brake actuator
temperature becomes high. (For details, see “Active traction
control system” on page 288.)
When the “ABS” warning light comes on, the vehicle stability
control system is not operating.
The lights will come on when the ignition key is turned to “ON”,
and will go off after a few seconds.
The lights may stay on for 60 seconds after the ignition key is
turned to the “ON” position. It is normal if they go off after a few
seconds.

STARTING AND DRIVING
292Depressing
the brake pedal repeatedly may turn on the lights.
It is normal if they go off after a few seconds.
When the “VSC/TRAC” warning light and “VSC OFF” indicator
light come on, the vehicle stability control system is not
operating, but there is no problem if you continue to drive.
In the following cases, contact your Lexus dealer:
 The “VSC/TRAC” warning light, “VSC OFF” indicator light
and slip indicator light do not come on after the ignition is
turned to on.
 The “VSC/TRAC” warning light and “VSC OFF” indicator
light remain on after the ignition is turned to on.
 The “VSC OFF” indicator light comes on while driving
without pushing the center differential lock switch.
CAUTION
Active traction control system, vehicle stability
control system and antilock brake system are
electronic systems designed to help the driver
maintain control under adverse conditions. They are
not a substitute for safe driving practices. Factors
including speed, road conditions and driver steering
input can all affect whether active traction control
system, vehicle stability control system and
antilock brake system will be effective in preventing
a loss of control. Always keep safety driving in mind.
If the slip indicator light flashes, 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. (See “Checking and replacing tires” on
page 438.)

STARTING AND DRIVING
297
Driving over the steps such as the joints on the road.
 Driving on roads where the road surface is pitted or
has other differences in surface height.
Install all 4 tires of specified size at appropriate
pressure: The antilock brake system detects vehicle
speeds using the speed s ensors for respective wheels’
turning speeds. The use of tires other than specified
may fail to detect the accurate turning speed resulting
in a longer stopping distance.“ABS” warning light
31X506
The light comes on when the ignition key is turned to the “ON”
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 “ABS” 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/or the
vehicle stability control system do/does not operate, but the
brake system still operates conventionally.
When the “ABS” 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.

IN CASE OF AN EMERGENCY
350
IF YOUR VEHICLE BECOMESSTUCK
If your vehicle becomes stuck in snow, mud, sand, etc.
then you may attempt to rock the vehicle free by moving
it forward and backward.
Turn off the active traction control system to become
unstuck to allow the tires to spin enough to remove the
vehicle from the obstruction. (For details, see “Vehicle
stability control system” on page 290.)
CAUTION
Do not attempt to rock the vehicle free by moving it
forward and backward if people or objects are anywhere
near the vehicle. During the rocking operation the
vehicle may suddenly move forward or backward as it
becomes unstuck, causing injury or damage to nearby
people or objects.
NOTICE
If you rock your vehicle, observe the following
precautions to prevent damage to the transmission and
other parts.
 Do not depress the accelerator pedal while shifting
the selector lever or before the transmission is
completely shifted to forward or reverse gear.
 Do not race the engine and avoid spinning the
wheels.
 If your vehicle remains stuck after rocking the vehicle
several times, consider other ways such as towing.

CHASSIS
432
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 All passenger vehicle 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
− 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 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
− 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 required by law.
Warning: The temperature grades for this tire are
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
436
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 428.
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 as this
could result in loss of control and could cause
death or serious injury.

CHASSIS
440
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.