LEXUS LS430 2005 Owners Manual

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362
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 ignition switch is turned to “ON”, 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.
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 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.
The slip indicator light comes on for a few seconds when the
ignition switch is turned to “ON”. If the indicator light does not
come on when the ignition is turned on, contact your Lexus
dealer.

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Traction control off mode
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If your wheels get stuck in a ditch when you are driving on
a severe off road and sand, turn off the traction control
system. This system that controls engine performance
interferes with the process of freeing your wheels.
To turn off: Push “TRAC OFF” switch.
The “TRAC OFF” indicator light will come on.
The vehicle stability control system is always activated even if
the traction control system is turned off.
To turn on: Push “TRAC OFF” switch once again.
The “TRAC OFF” indicator light will go off. “TRAC
OFF” indicator light comes on for a few seconds when
the ignition switch is turned to “ON”. It will come on again when
you push the “TRAC OFF” switch to turn off the system.
In the following cases, contact your Lexus dealer:
 The indicator light does not come on when the ignition
switch is turned to “ON”.
 The indicator light remains on after the ignition is turned on.
 The indicator light comes on in the normal driving mode
while driving.

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“Check VSC” warning message
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If the vehicle stability control system or the traction
control system malfunctions, the master warning light
and “TRAC OFF” indicator light come on. At this time a
warning tone sounds and the above message appears.
If the message appears, the 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.
VEHICLE STABILITY CONTROLSYSTEM
The vehicle stability control system helps provide
comprehensive control of the systems such as antilock
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.

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CAUTION
Do not rely excessively on the vehicle stability
control system. Even if the vehicle stability control
system is operating, you must always drive carefully
and attentively to avoid serious injury. Reckless
driving will result in an accident. If the slip indicator
light blinks, sounding an alarm, special care should
be taken while driving.
 Only use tires of specified size. The size,
manufacturer, brand and tread pattern for all 4 tires
should be the same. If you use the tires other than
specified, or different type or size, the vehicle
stability control system may not function correctly.
When replacing the tires or wheels, contact your
Lexus dealer.
 In situations where the road surface is covered with
ice or snow, your vehicle should be fitted with snow
tires or tire chains.
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Slip indicator light
If the vehicle is going to skid during driving, the slip indicator
light blinks and an alarm sounds intermittently. Special care
should be taken while driving.
The slip indicator light comes on for a few seconds when the
ignition switch is turned to “ON”. If the indicator light does not
come on when the ignition is turned on, contact your Lexus
dealer.

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“Check VSC” warning message
31L337a
If the vehicle stability control system or the traction
control system malfunctions, the master warning light
and “TRAC OFF” indicator light come on. At this time a
warning tone sounds and the above message appears.
If the message appears, the 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.
BRAKE SYSTEM
The tandem master cylinder brake system is a hydraulic
system with two separate sub −systems. If either sub −system
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 engine vacuum to power −assist the
brakes. If the engine should quit 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 reserved
vacuum.
 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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Antilock brake system
The antilock brake system is designed to automatically
help prevent lockup 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 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 forward.
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.

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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 u sing 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.“ABS” warning light
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 1 U.S.A. 2Canada
The light comes on when the ignition switch 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 traction control system and/or 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.

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If any 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 switch 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.
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.
Brake assist system
If you slam the brakes on such as in an emergency or
apply the brakes more firmly than usual such as when
descending the hill with the designated number of
occupants in the vehicle, the brake assist system
provides more powerful braking.
If you slam the brakes on or apply the brakes more firmly, 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).
For an explanation of this system’s warning light, see “ABS”
warning light on page 87 or 368.

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TIRE PRESSURE WARNINGSYSTEM
The tire pressure warning system is designed to provide
warning using a message in the multiinformation
display, master warning light and warning tone when tire
inflation pressure is critically low while driving. This
message appears to inform you that such low tire
pressure may hamper driving.
As this system is not designed to operate when the vehicle is
stopped, check the tire inflation pressure regularly. The
recommended cold tire inflation pressure, tire size and the
vehicle capacity weight are on the tire and loading information
label. (For instructions, see “Checking tire inflation pressure”
on page 468.)
Installed tires should be of the specified size. They should be
of the same size and construction. If tires other than the
specified size are used, or if tires of different sizes or
constructions are mixed, the tire pressure warning system will
not function properly.
Low tire pressure warning message
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When the low tire inflation pressure is detected while
driving, the master warning light comes on, the above
message appears and a warning tone sounds.
If the above message appears and adjust the tire inflation
pressure to the specified level as soon as possible. Push the
tire pressure warning system reset switch for a few seconds
and make sure the warning message goes off. If the message
still remains on, have your vehicle checked by your Lexus
dealer as soon as possible.
The tire pressure warning system does not function
properly under certain circumstances. In the following
cases, the low tire pressure warning may not turn on even
if the tire inflation pressure is low, or it may turn on when
the tire inflation pressure is actually normal.
 A compact spare tire, snow tires, or tire chains are used.
 The tire inflation pressure is excessively higher than
specified, or tire inflation pressure suddenly drops due to
bursting or other causes.
 You are driving on slippery road surfaces such as rough or
frozen roads.
 You are driving under 30 km/h (19 mph) or above 100 km/h
(62 mph) for less than 5 minutes.
 The tires differ in tread pattern or manufacturer.
 The tires are not the specified size.

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The degree of the tread wear is very different among the
installed tires.
 Rapid acceleration/deceleration or sharp turns are
continued.
 Towing a trailer.
 The loading is over the limit or unbalanced.
 Initialization was not performed correctly after replacing or
rotating tires or wheels.
 The outside temperature is below 0 C (32F) or above
40 C (104 F).
If the warning message appears again on the
multi−information display after adjusting tire inflation pressure,
the system may be malfunctioning. Have your vehicle
checked by your Lexus dealer as soon as possible.
CAUTION
When the tire pressure warning message appears,
observe the following instructions:
 Adjust the tire inflation pressure to the specified level
as soon as possible.
 Avoid abrupt steering wheel maneuvering and
braking. If the vehicle tires are deteriorated, you
could lose control of the steering wheel or the brakes,
causing death or serious injury.
Note: The tire pressure mon itoring system on your
vehicle will warn you when one of your tires is
significantly underinflated and when some
combinations of your tires are significantly
underinflated. However, there are other combinations
of significantly underinflated tires for which your tire
pressure warning system may not warn you. These
other combinations are relatively common, accounting
for approximately half the instances in which vehicles
have significantly underinflated tires. For example,
your system may not warn you when both tires on the
same side or on the same axle of your vehicle are
significantly underinflated. It is particularly important,
therefore, for you to check the tire inflation pressure in
all of your tires regularly and maintain proper pressure.