2000 Lexus LS400 lexus LS400 2000 Engine / LEXUS 2000 LS400 OWNER'S MANUAL (OM50533U)

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320
CAUTION
Do not rely excessively on the vehicle skid control
system. Even if the vehicle skid control system is
operating, it is not that your vehicle is absolutely
safe. Reckless driving will result in an unexpected
accident. Always keep safety driving in mind. If the
slip indicator light flashes, 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 skid
control system may not function correctly. When
replacing the tires or wheels, contact your Lexus
dealer.

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321
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 be longer. 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!

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322
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 be longer.
Anti±lock brake system
The anti±lock brake system is designed to help
prevent lock±up of the wheels during a sudden
braking or braking on slippery road surfaces. This
assists in providing 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, just hold the
brake pedal down more firmly. Especially, in a panic stop,
you need to keep it depressed more firmly, and do not pump
the brake. Pumping the brake pedal makes the stopping dis-
tance longer.

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323
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 the manhole cover, the steel plate under the
construction, joints in the 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 is started. 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, however, 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 to the forward.

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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 tires 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.

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325
Anti±lock brake system is not designed to shorten the
stopping distance: Always drive at the moderate speed
and maintain a safe distance from the vehicle in front of
you. Compared with vehicles not fitted with 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 designated
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
326ºABSº warning light
31L019±2
The light comes on with the ignition key turned to ªONº.
If the anti±lock brake system and the brake assist
system work properly, the light goes out after a few
seconds. Thereafter, if either of the systems
malfunctions, the light comes on.
When the ªABSº 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 skid control system do/does not
operate, but the brake system still operates
conventionally.
When the ªABSº 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. If the following conditions occur, this indicates a
malfunction somewhere in the parts monitored by
the warning light system. Contact your Lexus
dealer as soon as possible to service the vehicle.

The light does not come on with the ignition key
turned to ªONº, or remains on.
 The light comes on while driving.
If the light lit during driving goes out and does not come
on again, it is a normal operation.

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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
ªABSº w arning light on page 68 or 326 and ªV ehicle skid
control failure warningº on page 318.