2003 Lexus GX470 traction control

STARTING AND DRIVING
323
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 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 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
the “VSC TRAC” 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 “ON”.
 The warning light remains on after the ignition key is turned
to “ON”.
 The warning light comes on while driving.
VEHICLE SKID CONTROL SYSTEM
The vehicle skid control system helps provide integrated
control of the systems such as antilock brake system,
traction control, engine control, etc. This system
automatically controls t he 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 vehicle skid control activates when the vehicle speed is
more than following speed:
Four− wheel drive control lever in “H” 15 km/h (9 mph) . . .
Four−wheel drive control lever in “L” 30 km/h (19 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 system is in the
self−check mode, but does not indicate a malfunction.
CAUTION
 Do not rely excessively on the vehicle skid control
system. Even if the vehicle skid 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
325

The indicator light remains on after the ignition is turned on.
 The indicator light comes on when the system is on while
driving.
NOTICE
Make sure that the center dif ferential lock indicator light
goes off before normal driving.
“VSC TRAC” warning light
This light warns that when there is a problem somewhere in the
following. 
Vehicle skid control system
 Active traction control system
 Downhill assist control system
 Hill− start assist control system
When the system is normal and the ignition key is turned to
“ON”, 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 “ON”
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 skid 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 “ON”.
 The warning light remains on after the ignition key is turned
to “ON”.
 The warning light comes on while driving.

STARTING AND DRIVING
327
If 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 “DAC” 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 “DAC”
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 “ON”. 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
328
“VSC TRAC” warning light
If there is any abnormality in the system, the “VSC TRAC”
warning light will come on. When the “DAC” switch is
pushed, the downhill assist control system indicator light
also flash.
If the “VSC TRAC” 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 skid control system
When the system is normal and the ignition key is turned to
“ON”, 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 “ON”
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 TRAC”
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 TRAC” 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 “ON”.
 The warning light remains on after the ignition key is turned
to “ON”.
 The warning light comes on while driving.

STARTING AND DRIVING
330The slip indicator light comes on for a few seconds when the
ignition key is turned to “ON”. 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 TRAC” warning light
If there is any abnormality in the system, the “VSC TRAC”
warning light will come on.
If the system malfunctions, the “VSC TRAC” warning light will
come on.
If the “VSC TRAC” 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 skid control system
When the system is normal and the ignition key is turned to
“ON”, 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 “ON”
position.

STARTING AND DRIVING
334“ABS” warning light
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 the
vehicle skid 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. If either of the following conditions occurs, this indicates
a malfunction somewhere in the parts 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 “ON” 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 “ABS” 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 antilock 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 the malfunction:
 The light may stay on for about 60 seconds after the ignition
key is turned to the “ON” 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
435
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 an air loss occurs while driving, do not continue driving with
a deflated tire. 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 also applies to the spare tire and tires stored for future use.
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. 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.

CHASSIS
436Warning: 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.
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.
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.
 Do not use tires of different brands, sizes,
construction or tread patterns, as this may cause
dangerous handling characteristics result ing in loss
of control.