2004 Lexus IS300 Electrical Components / LEXUS 2004 IS300 OWNER'S MANUAL (OM53461U)

STARTING AND DRIVING
258
VEHICLE STABILITY CONTROLSYSTEM
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.
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 unexpected 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,
manufacture, 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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259
SV31037

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 key is turned to ºONº. If the indicator light does not
come on when the ignition is turned on, contact your Lexus
dealer.
ºVSCº warning light
SV31042
This light warns that there is a problem somewhere in the
vehicle stability control system or traction control system.
The light will come on when the ignition key is turned to ºONº
and will go off after a few seconds.
If the light comes on while driving, the vehicle stability control
system and traction control system do not work. However, as
conventional braking operates when applied, there is no
problem to continue your driving.
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STARTING AND DRIVING
260In the following cases, contact your Lexus dealer:

The warning light does not come on after the ignition key is
turned to ºONº.
 The warning light remains on after the ignition key is turned
to ºONº.
 The warning light comes on while driving.
The ºTRAC OFFº indicator/warning light will come on when the
ºVSCº warning light comes on even if the ºTRAC OFFº switch
is not pushed.
ELECTRONIC THROTTLE CONTROL SYSTEM
The electronic throttle control system always maintains
appropriate engine output in relation to the accelerator
opening in all driving conditions.
SV31038
You can select the snow mode by pushing the ºSNOWº
switch. The ºSNOWº indicator light will come on.
Snow mode: Decreases the engine output to minimize rear
wheel spinning on snowcovered or slippery roads.
To return to the normal mode, push the ºSNOWº switch again.
The ºSNOWº indicator light will go off.
When you turn the ignition switch off in the snow mode, the
mode automatically changes to the normal mode.
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261
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.
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:
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262
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 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.
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ºABSº warning light
SV31014

U.S.A.
SV31031

CANADA
The light comes on when the ignition key is turned to the ºONº
position. If the anti-lock brake system and the brake assist
work properly, the light turns off after a few seconds.
Thereafter, if either of the systems malfunctions, the light
comes on again.
When the ºABSº 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 not operate, but the brake system
still operates conventionally.
When the ºABSº warning light is on (and the brake system
warning light is off), the anti-lock brake system and/or the
traction
control system do/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 ºONº 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.
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CAUTION
If the ºABSº 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 anti-lock brake system will fail
but also the vehicle will become extremely unstable
during braking.
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).For an explanation of this system's warning light, see ºABSº
warning light on page 54 or 263.
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BRAKE PAD WEAR INDICATORS
SS31030
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 nearest Lexus
dealer immediately.
Avoid continuous driving with the warning noise.
Continuous driving without replacing the brake pads will cause
expensive rotor damage and increasing brake pedal effort to
get the same stopping distance.
LIMITED-SLIP DIFFERENTIAL
Some vehicles are equipped with a limited-slip differential. If
one rear wheel begins to spin, the limited-slip differential is
designed to aid traction by automatically transmitting driving
force to the other rear wheel. If you are not sure whether your
vehicle is equipped with one, you can ask your Lexus dealer.
CAUTION
Do not start or run the engine while your vehicle is
supported by a j ack. The vehicle could be driven off the
jack and could pose a danger or result in serious injury.
NOTICE
Use only a spare tire of the same size, construction and
load capacity as the original tires on your Lexusbecause damage to the limited-slip differential couldpossibly occur with another tire type.
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