steering Lexus GS300 2006 Starting and Driving

STARTING AND DRIVING
425 While the system is not functioning, a larger degree of wheel
maneuvering is needed during driving at low speed. If the
center position of the steering wheel is changed frequently,
have your vehicle inspected at your Lexus dealer.
CAUTION
Take due care especially when driving at low speed as
the vehicle changes direction in greater proportion to
the steering wheel maneuvering.
NOTICE
Do not disconnect the battery with the steering wheel
turned, or the center position of the steering wheel
could be slightly and temporarily changed. However,
after driving for a short while, the system will return to
normal and the center position of the steering wheel will
be in the appropriate position.
If you disconnect and reconnect the battery terminal, the
system is reset temporarily. However, it is no problem to drive.
Drive for a short while, the system will be set automatically and
return to normal.
Variable gear ratio steering system failure
warning
G31044
If there is any malfunction in the system, the above message
appears and the master warning light comes on.
If the warning message and light come on while driving, the
system is not working. Although conventional steering
operates when maneuvered, a larger degree of wheel
maneuvering (than at the time when the system is functioning
properly) is needed when driving at low speed. At this time, the
center position of the steering wheel could be changed.
Although it is no problem to continue driving, have your vehicle
repaired at your Lexus dealer.

STARTING AND DRIVING
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.

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
432
ELECTRIC POWER STEERING
SYSTEM
The electric power steering system, using an electric
motor, assists the turning of the steering wheel.
In the following cases, you may feel the steering becomes
heavy. However, the electric power steering system
warning light does not come on. (Because it is not a
malfunction.)
When maneuvering or turning frequently over a long time, the
power steering effect will be reduced to prevent the system
from overheating. Avoid turning the steering wheel, or stop the
vehicle and select the engine switch in “ACC” or “OFF” mode.
The system will become cool in about 10 minutes.
NOTICE
Frequent maneuvering and turning over a long time may
cause damage to the system in which the mechanism
prevents overheating of the electric power steering
system.
When the battery is discharged, check the battery’s condition.
If necessary, recharge or replace the battery. For details, see
“Checking battery condition” on page 571.
G31040

Electric power steering system warning light
The light comes on when the engine switch is selected in
“IG−ON” mode. If the electric power steering system works
properly, the light turns off after a few seconds. If the system
has malfunctions, the light comes on again.
If 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 the engine switch is
selected in “IG−ON” mode or remains on.
The light stays on while you are driving.

STARTING AND DRIVING
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CAUTION
If the electric power steering system warning light
comes on, take your vehicle to your Lexus dealer as
soon as possible. In this case, more effort is required
for the steering wheel to turn than usual. Drive your
vehicle while firmly gripping the steering wheel.
TIRE PRESSURE WARNING
SYSTEM
G31003

Low tire pressure warning light
The light warns you that the tire inflation pressure is low.
The low tire pressure warning light comes on when the engine
switch is selected in “IG−ON” mode and goes off after a few
seconds. This means the low tire pressure warning light is
operating properly. If the tire inflation pressure becomes low,
the light comes on again. At this time, the master warning light
comes on and the message “LOW TIRE” appears on the
multi−information display.

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CAUTION
If the low tire pressure warning light comes on, take
your vehicle to the nearest Lexus dealer or authorized
tire dealer or gas station as soon as possible, observing
the following instructions:
Decelerate as soon as possible to the most
appropriate speed that conditions permit. Do not
drive over 90 km/h (55 mph).
Avoid abrupt steering wheel maneuvering and
braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes,
causing death or serious injury.
The warning system may not activate immediately if
bursts or sudden air leakage should occur.
When the tyre pressure warning system warning light is
lit, one or more of your tyres is significantly
under−inflated. You should stop and check your tyres
as soon as possible, and inflate them to the proper
pressure as indicated on the vehicle’s tyre information
placard. Driving on a significantly under−inflated tire
causes the tyre to overheat and can lead to tyre failure.
Under−inflation also reduces fuel efficiency and tyre
tread life, and may affect the vehicle’s handling and
stopping ability. Each tyre, including the spare, should
be checked monthly when cold and set to the
recommended inflation pressure as specified in the
vehicle placard and owner’s manual.
NOTICE
Do not use liquid sealants for a flat tire as tire
pressure sensors will be damaged.
Take due care not to go over a curb stone and be
careful of the holes in the road because deflated tire
pressure affects tire cushion performance. The
wheels, tires, body, suspension and other
components could be damaged.
Your ground clearance is reduced if the run−flat tire
goes flat so avoid driving over obstacles and drive
slowly on rough, unpaved roads and speed bumps.
Also, do not attempt to go through an automatic car
wash as the vehicle may get caught, resulting in
damage.
When the tires must be replaced, have them replaced
by the nearest Lexus dealer or authorized tire dealer.
The tire pressure sensor will be affected by the
installation or removal of tires.
When the tires must be replaced, replace the
grommets for tire pressure sensors as well.

STARTING AND DRIVING
436Vehicles with standard tires:
Stop your vehicle at a safe place as soon as possible and
check that the tire inflation pressure is as specified on the tire
and loading information label. If the low tire pressure warning
light comes on even after tire inflation pressure adjustment, it
is probable that you have a flat tire. If the tire goes flat, change
to the spare tire. (See page 469.)
The spare tire is not equipped with the tire pressure sensor.
So, the low tire pressure warning light remains on even if the
spare tire is mounted.
The light goes off a few minutes after air is put into the deflated
tire.
CAUTION
If the low tire pressure warning light comes on, observe
the following instructions:
Decelerate as soon as possible to the most
appropriate speed that conditions permit.
Avoid abrupt steering wheel maneuvering and
braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes,
causing death or serious injury.
The warning system may not activate immediately if
bursts or sudden air leakage should occur.
When the tyre pressure warning system warning light is
lit, one or more of your tyres is significantly
under−inflated. You should stop and check your tyres
as soon as possible, and inflate them to the proper
pressure as indicated on the vehicle’s tyre information
placard. Driving on a significantly under−inflated tire
causes the tyre to overheat and can lead to tyre failure.
Under−inflation also reduces fuel efficiency and tyre
tread life, and may affect the vehicle’s handling and
stopping ability. Each tyre, including the spare, should
be checked monthly when cold and set to the
recommended inflation pressure as specified in the
vehicle placard and owner’s manual.