2006 Lexus GX470 Basic Functions In Frequent Use / LEXUS 2006 GX470 OWNER'S MANUAL (OM60B99U)

STARTING AND DRIVING
380If 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
 Active traction control system
 Vehicle stability 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.
If the “VSC TRAC” warning light and slip indicator 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.
HILLSTART ASSIST CONTROL
The hillstart assist control assists you in starting to move
up a steep or slippery hill. When you start to move up the
hill slope, the system helps to prevent the vehicle from
rolling backward in the interval while you move your foot
from the brake pedal to the accelerator pedal.
CAUTION
 Do not rely excessively on the hillstart assist
control. The vehicle may not be able to start
smoothly on road surfaces or offroad surfaces such
as extremely steep slopes or icy roads, on which
sliding can occur very easily.
 Do not use the hillstart assist control to stop the
vehicle. The hillstart assist control is not designed
as a function for stopping the vehicle on a uphill
slope.

STARTING AND DRIVING
381
The hillstart assist control will operate for 5 seconds
maximally when all of the following conditions apply.

When the transmission is in any of positions “D”, “4”,
“3”, “2” or “L”
 When the brake pedal is not depressed
The system is designed to operate when the vehicle is starting
on an uphill slope; therefore, if the transmission is in “P” or “\
N”
it will not operate. It will not operate either if the vehicle starts
to move in reverse on a slope with the transmission in the “R”.
 Slip indicator light
When the hill−start assist control is operating, the slip indicator
light flashes and an alarm sounds intermittently. At the same
time, the stop lamps and high mounted stoplight are lit.
The 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 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 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.
The brake actuator temperature increases during continuous
operation of the following systems.
 Active traction control system
 Vehicle stability control system
 Downhill assist control system
 Hill −start assist control
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 hill −start assist control can no
longer operate. In this case, stop your vehicle immediately at
a safe place.

STARTING AND DRIVING
382If 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 slip indicator light
will come on and the hill −start assist control stops operating
temporarily in order to protect the brake actuator. (Although
the hill−start assist control does not operate, it is no problem
to continue your driving.) The system will be automatically
restored after a short time and the slip indicator light goes out.
“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.
 Downhill assist control system
 Active traction control system
 Vehicle stability 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
383
Depressing the brake pedal repeatedly may turn on the light.
It is normal if it goes out after a few seconds.
If the “VSC TRAC” warning light and slip indicator 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.
BRAKE SYSTEM
This brake system has 2 independent hydraulic circuits. If
either circuit should fail, the o ther will still work. However, the
pedal will be harder to press, and your stopping distance will
increase. Also, the brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a single brake
system. Have your brakes fixed immediately.
Brake booster
The brake booster uses brake fluid pressurized by the pump
to power−assist the brakes. If the brake booster fails during
driving, the brake system warning light comes on and buzzer
sounds continuously. In this case, the brakes may not work
properly. If they do not work well, depress the brake pedal
firmly. If the brake system warning light comes on, immediately
stop your vehicle and contact your Lexus dealer.
The brake system warning light may stay on for about 60
seconds after the ignition key is turned to the “ON” position. It
is normal if the light turns off after a while.
Depressing the brake pedal repeatedly may turn on the brake
system warning light and buzzer. It is normal if the light goes
out and the buzzer stops sounding after a few seconds.

STARTING AND DRIVING
384You may hear a small sound in the engine compartment after
the engine is started or the brake pedal is depressed
repeatedly. This is a pump pulsating sound of the brake
system, and it is not a malfunction.
CAUTION

Do not pump the brake pedal if the engine stalls.
Each push on the pedal uses up your brake fluid
pressure reserve.
 Even if the power assist is completely lost, the brakes
will still work. But you will have to push the pedal
hard, much harder than normal. And your braking
distance will increase.
Antilock brake system
The antilock brake system is designed to automatically
help prevent lockup of the wheels during a sudden brake
or braking on slippery road surfaces. This assists in
providing directional stability and steering performance
of the vehicle under these circumstances.
Effective way to press the ABS brake pedal: When the
anti−lock brake system function is in action, you may feel the
brake pedal pulsating and hear a noise. In this situation, to
let the anti−lock brake system work for you, just hold the
brake pedal down more firmly. Do not pump the brake in a
panic stop. This will result in reduced braking performance.
The anti−lock brake system becomes operative after the
vehicle has accelerated to a speed in excess of approximately
10 km/h (6 mph). It stops operating when the vehicle
decelerates to a speed below approximately 5 km/h (3 mph).
Depressing the brake pedal on slippery road surfaces such as
on a manhole cover, a steel plate at a construction site, joints
in a bridge, etc. on a rainy day tends to activate the anti −lock
brake system.
You may hear a click or motor 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
anti−lock brake system is in the self −check mode, and does not
indicate a malfunction.
When the antilock brake system is activated, the
following conditions may occur. They do not indicate a
malfunction of the system:
 You may hear the anti −lock brake system operating and feel
the brake pedal pulsating and the vibrations of the vehicle
body and steering wheel. You may also hear the motor
sound in the engine compartment even after the vehicle is
stopped.
 At the end of the anti−lock brake system activation, the
brake pedal may move a little to the forward.

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385
CAUTION
Do not overestimate the antilock brake system:
Although the antilock brake system assists in
providing vehicle control, it is still important to drive
with all due care and maintain a moderate speed and
safe distance from the vehicle in front of you, because
there are limits to the vehicle stability and effectiveness
of steering wheel operation even with the antilock
brake system on.
If tire grip performance exceeds its capability, or if
hydroplaning occurs during high speed driving in the
rain, the antilock brake system does not provide
vehicle control.
Antilock brake system is not designed to shorten the
stopping distance: Always drive at a moderate speed
and maintain a safe distance from the vehicle in front of
you. Compared with vehicles without an antilock
brake system, your vehicle may require a longer
stopping distance in the following cases:
 Driving on rough, gravel or snowcovered roads.
 Driving with tire chains installed.
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 sensors 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.

STARTING AND DRIVING
386“ABS” warning light
1U.S.A.2Canada
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 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. 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 “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 a 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.

STARTING AND DRIVING
387
Brake assist system
When you slam the brakes on, the brake assist system
judges as an emergency stop and provides more powerful
braking for a driver who cannot hold down the brake pedal
firmly.
When you slam the brakes on, more powerful braking will be
applied. At this time, you may hear a sound in the engine
compartment and feel the vibrations of the brake pedal. This
does not indicate a malfunction.
The brake assist system becomes operative after the vehicle
has accelerated to a speed in excess of approximately 10 km/h
(6 mph). It stops operating when the vehicle decelerates to a
speed below approximately 5 km/h (3 mph).
The brake assist system may not work for about 60 seconds
after the engine is started.
For an explanation of this system’s warning light, see “ABS
warning light” on page 57.
Drumindisc type parking brake system
Your vehicle has a drum−in−disc type parking brake system.
This type of brake system needs bedding −down of the brake
shoes periodically or whenever the parking brake shoes and/or
drums are replaced.
Have your Lexus dealer perform the bedding −down.
TIRE PRESSURE WARNING
SYSTEM
The tire pressure warning system is designed to provide
warning when tire inflation pressure of one or more of
your tires (including the spare tire) is low. The low tire
pressure warning light comes on to inform you that low
tire inflation pressure may hamper driving.
Low tire pressure warning light
This light comes on when the ignition key is turned to the “ON”
position. It goes off after a few seconds. This indicates that the
tire pressure warning system is functioning properly.