2006 Lexus GS300 stop start

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)

STARTING AND DRIVING
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.

STARTING AND DRIVING
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.

STARTING AND DRIVING
429
CAUTION
Do not overestimate the anti−lock brake system:
Although the anti−lock 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 anti−lock
brake system on.
If tire grip performance exceeds its capability, or if
hydroplaning occurs during high speed driving in the
rain, the anti−lock brake system does not provide
vehicle control.
Anti−lock 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 anti−lock
brake system, your vehicle may require a longer
stopping distance in the following cases:
Driving on rough, gravel or snow−covered 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 anti−lock 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
430“ABS” warning light
G31080

1
U.S.A. 2
Canada
GS430—The light comes on when the engine switch is
selected in “IG−ON” mode. If the anti−lock brake system and
the brake assist system work properly, the light turns off in a
few seconds after the engine is started.
GS300—The light comes on for a few seconds when the
engine switch is selected in “IG−ON” mode. It indicates the
anti−lock brake system and the brake assist system work
properly.
If either system malfunctions, the light comes on again.
When the “ABS” warning light is on, the anti−lock brake system
and the brake assist system do not operate, but the brake
system still operates conventionally.If either of the following conditions occur, 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 engine switch is selected
in “IG−ON” mode.
The light remains on after the engine is started (GS430), or
remains on after the engine switch is selected in “IG−ON”
mode (GS300).
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 (red), 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.
GS430 only—Either of the following conditions may
occur, but does not indicate a malfunction:
The light may stay on for about 60 seconds after the engine
is started. 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
431
Drum−in−disc 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.
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 78 or 430.
BRAKE PAD WEAR LIMIT
INDICATORS
G31006
The brake pad wear limit indicators on your disc brakes
give a warning noise when the brake pads are worn to the
extent that replacement is required.
If you hear a squealing or scraping noise while driving, have
the brake pads checked and replaced by your Lexus dealer as
soon as possible. Expensive rotor damage can result if the
pads are not replaced when needed.
GS430 front brake only—
The high brake performance is achieved by proper wear of
brake pads and discs. As a result, the brake discs may wear
earlier than the ones on the conventional brake system.
When brake pads are replaced, brake disc thickness is
required to be measured.
It is dangerous to continue driving when brake pads and discs
have exceeded the wear limit.