1999 LEXUS SC300 Owners Manual

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247
You can turn off the traction control system by pushing
the ºTRAC OFFº switch. The ºTRAC OFFº indicator/
warning light will then come on. Pushing the ºTRAC
OFFº switch a second time turns the system back on and
extinguishes the ºTRAC OFFº indicator/warning light.
You may hear a slight clicking noise in the engine
compartment when the engine is started. This means that the
traction control system is in the self±check mode, and does
not indicate malfunction.
When the traction control system is operating, you may feel
vibration of your vehicle, caused by operation of the brakes.
This indicates the system is functioning properly.
When getting the vehicle out of mud or new snow, etc. the
traction control system will help operate to prevent the wheels
from spinning.

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248
Traction control failure warning
If the ºTRAC OFFº indicator/warning light flashes, contact
your Lexus dealer as soon as possible. There may be trouble
in the traction control system.
CAUTION
Under certain slippery road conditions, full traction of the
vehicle and power to the 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 will cause the vehicle to lose traction. 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 pace.
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.

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249
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 reserve 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 vacuum 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 be
longer.

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250
Anti±lock brake system
The anti±lock brake system is designed to automatically
help prevent lock±up of the wheels during a sudden brake
or braking on slippery road surfaces. This assists in
providing directional stability and steering performance
of the vehicle under these circumstances.
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).
You may hear a 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.
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. Pumping the
brake pedal makes the stopping distance longer.

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251
The brake pedal pulsation caused by the anti±lock brake
system may indicate hazardous road surface conditions.
Although the anti±lock brake system assists in providing
vehicle control, it is still important to drive with all due care,
because
the anti±lock brake system cannot overcome the laws
of physics that act on your vehicle:
 Braking capability is dependent on tire friction with the
road surface. 
Even though the anti±lock brake system is operating, a
driver cannot maintain full control on certain slippery road
surfaces, when cornering at high speeds, or in violent
maneuvers.
 Avoid high speeds on wet roads. The anti±lock brake
system cannot eliminate the risk of hydroplaning and loss
of tire friction.
Always 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 on roads where the road surface is pitted or has
other differences in surface height.

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252ºABSº warning light

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253
This light comes on when the ignition key is turned to the
ºONº
position. After about a few seconds, the light will go
off.
If either of the following conditions occurs, 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 as described above, or remains
on.
 The light comes on while driving.
Even if the anti±lock brake system should fail, the brake
system will still operate conventionally. But when the ºABSº
warning light is on (and the brake system warning light is off),
anti±lock brake system is not assisting brake performance so
that the wheels could lock up during a sudden brake or
braking on slippery road surfaces. Have your vehicle
checked by your Lexus dealer as soon as possible.
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.

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BRAKE PAD WEAR LIMITINDICATORS
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.