2006 Lexus GS300 brake

STARTING AND DRIVING
418
TRACTION CONTROL SYSTEM
The traction control system automatically helps prevent
the spinning of rear wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the engine switch is selected in “IG−ON” mode, the
system automatically turns on.
CAUTION
Under certain slippery road conditions, full traction of
the vehicle and power against rear wheels cannot be
maintained, even though the traction control system is
in operation. Do not drive the vehicle under any speed
or maneuvering conditions which may cause the
vehicle to lose traction control. 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
present road conditions.
G31038

Slip indicator light
Leave the system on during the ordinary driving so that it
can operate when needed.
You may hear a sound in the engine compartment for a few
seconds just after the vehicle begins to move. This means that
the traction control system is in the self−check mode, but does
not indicate a malfunction.
When the traction control system is operating, the following
conditions occur:
The system controls the spinning of the rear wheels. At this
time, the slip indicator light blinks.
You may feel vibration or noise in your vehicle, caused by
operation of the brakes. This indicates the system is
functioning properly.
GS430—The slip indicator light comes on when the engine
switch is selected in “IG−ON” mode. The light goes off when
the engine is started.

STARTING AND DRIVING
420
Traction control system failure warning
G31039

1
GS430 2
GS300
If the traction control system malfunctions, the slip
indicator light (two−wheel drive models only) and brake
system warning light (yellow) come on. At this time, the
above message appears. (GS430 only—In some cases,
the multi−information display shows either “CHECK VSC”
or “CHECK ECB” only.)
If the message appears, the traction control system, vehicle
stability control system and hill−start assist control system do
not work. Although it is no problem to continue driving, have
your vehicle checked by your Lexus dealer as soon as
possible.
VEHICLE STABILITY CONTROL
SYSTEM
The vehicle stability control system helps provide
comprehensive control of the systems such as anti−lock
brake system, traction control, engine control, etc. This
system automatically controls the brakes and engine to
help prevent the vehicle from skidding when cornering on
a slippery road surface or operating steering wheel
abruptly.
This system activates 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 just after the vehicle begins to move. This means that
the system is in the self−check mode, but does not indicate a
malfunction.

STARTING AND DRIVING
422
Vehicle stability control failure warning
G31039

1
GS430 2
GS300
If the vehicle stability control system malfunctions, the
slip indicator light (two−wheel drive models only) and
brake system warning light (yellow) come on. At this time,
the above message appears. (GS430 only—In some
cases, the multi−information display shows either
“CHECK VSC” or “CHECK ECB” only.)
If the message appears, the vehicle stability control system,
traction control system and hill−start assist control system do
not work. Although it is no problem to continue driving, have
your vehicle checked by your Lexus dealer as soon as
possible.
HILL−START ASSIST CONTROL
SYSTEM
The hill−start assist control system 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 hill−start assist control
system. The vehicle may not be able to start
smoothly on road surfaces or off−road surfaces such
as extremely steep slopes or icy roads, on which
sliding can occur very easily.
Do not use the hill−start assist control system to stop
the vehicle. This system is not designed for stopping
the vehicle on an uphill slope.

STARTING AND DRIVING
423 The hill−start assist control system will operate for 5
seconds maximally when all of the following conditions
apply.
When the selector lever is in “D” or “S” position
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 selector lever 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 selector lever in “R”.
When the hill−start assist control system is operating, you may
hear a sound. This indicates the hill−start assist control is
operating normally and does not indicate a malfunction.
G31038

Slip indicator light
When the hill−start assist control system is operating, the slip
indicator light flashes. At the same time, the stop lights and
high mounted stoplight are lit.GS430—The slip indicator light comes on when the engine
switch is selected in “IG−ON” mode. The light goes off when
the engine is started.
GS300—The slip indicator light comes on for a few seconds
when the engine switch is selected in “IG−ON” mode.
If the indicator light does not come on when the engine switch
is selected in “IG−ON” mode, contact your Lexus dealer.
Keep the following in mind 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 for
stopping the vehicle on an uphill slope. When stopping the
vehicle, be sure to depress the brake pedal.

STARTING AND DRIVING
424
Hill−start assist control system failure
warning
G31039

1
GS430 2
GS300
If the hill−start assist control system malfunctions, the
slip indicator light (two−wheel drive models only) and
brake system warning light (yellow) come on. At this time,
the above message appears. (GS430 only—In some
cases, the multi−information display shows either
“CHECK VSC” or “CHECK ECB” only.)
If the message appears, the hill−start assist control system,
vehicle stability control system and traction control system do
not work. Although it is no problem to continue driving, have
your vehicle checked by your Lexus dealer as soon as
possible.
VARIABLE GEAR RATIO
STEERING SYSTEM
(GS430 only)
The variable gear ratio steering system adjusts the wheel
turning angle depending on the vehicle speed and how
much you turn the steering wheel.
The vehicle wheel turning angle will be changed with a smaller
degree of wheel maneuvering when you are driving at very low
speed such as when putting your vehicle into a garage.
When you start or stop the engine, you may hear a small noise
and the steering wheel may move slightly. This is caused when
the system starts or stops, and does not indicate a malfunction.
In the following cases, to prevent the system from overheating,
the system could be temporarily deactivated with the change
in the center position of the steering wheel. This is not a
malfunction. After the cause of the problem is eliminated, the
system will return to normal automatically after a few minutes.
If you continue maneuvering the steering wheel when the
vehicle is stopped or running at very low speed
If you continue driving holding the steering wheel to the
extreme right or left
If you maneuver the steering wheel immediately after
starting the engine at less than about −30C (−22F)

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426
VEHICLE DYNAMICS
INTEGRATED MANAGEMENT
(GS430 only)
Vehicle Dynamics Integrated Management (VDIM) helps
manage control for vehicle stability control system,
anti−lock brake system, brake assist system, traction
control system, engine output control, hill−start assist
control system and also manages variable gear ratio
steering system and electric power steering system.
In order to control sudden steering wheel operation and
the sideslip on slippery road surfaces, this system
provides excellent vehicle stability by automatically
controlling the brake, engine output and front wheel
angle.
The state of the tires will affect the performance of the vehicle
dynamics integrated management system. Be sure to check
the following:
Are tires of specified size installed?
Are tires of identical type installed?
Do the tires have stipulated tire pressure?
Are the tires worn?
A problem with the tires or modified suspension systems will
have an adverse effect on the system and may cause a
malfunction, so be careful.When the slip indicator light comes on, and the message
“CHECK ECB” appears on the multi−information display, the
vehicle dynamics integrated management does not operate.
Have your vehicle checked by your Lexus dealer as soon as
possible.
In addition, when the master warning light comes on, and the
message “CHECK VGRS” or “CHECK P/S” appears on the
multi−information display, the system will not be temporarily
functioning. Although it is no problem in driving as usual, have
your vehicle checked by your Lexus dealer as soon as
possible.
CAUTION
Do not overestimate the vehicle dynamics integrated
management. Even when this management is
functional, there is a limit to vehicle stability, and
irresponsible driving may lead to an accident. When
driving, you should always pay attention to your speed
and keep a safe distance between your vehicle and the
vehicle in front.

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427
BRAKE SYSTEM
This brake system has 2 independent hydraulic circuits. If
either circuit should fail, the other 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
(GS430) or engine vacuum (GS300) to power−assist the
brakes. If the brake booster fails during driving, the brake
system warning light (red) comes on. 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 (red)
comes on, immediately stop your vehicle and contact your
Lexus dealer.
GS430 only—Either of the following conditions may
occur, but does not indicate a malfunction:
The brake system warning light (red) may stay on for about
60 seconds after the engine is started. It is normal if the light
turns off after a while.
Depressing the brake pedal repeatedly may turn on the
brake system warning light (red). It is normal if the light goes
out after a few seconds.GS430:
You 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.
GS300:
If the engine should stop while you are driving, you can bring
the vehicle to a stop with normal pedal pressure. There is
enough reserved vacuum for one or two stops—but no more!
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.

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428
Anti−lock brake system
The anti−lock brake system is designed to automatically
help prevent lock−up of the wheels during a sudden
braking 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 anti−lock 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 forward.