warning light Lexus IS300 2005 Basic Functions / LEXUS 2005 IS300 (OM53489U) Owner's Guide

STARTING AND DRIVING
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:
04 06.30

STARTING AND DRIVING
263
ªABSº warning light
SV31014

U.S.A.
SV31031

CANADA
The light comes on when the ignition key is turned to the ªONº
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 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
stability control system do 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 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 ªONº 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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STARTING AND DRIVING
264
CAUTION
If the ªABSº 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 ªABSº
warning light on page 54 or 263.
04 06.30

MAINTENANCE
310Brake fluid level
Make sure the brake fluid level is correct. See page 349 for
additional information.
Engine oil level
Check the level on the dipstick with the engine turned off and
the vehicle parked on a level spot. See page 333 for additional
information.
Power steering fluid level
Check the level on the dipstick. The level should be in the
ªHOTº or ªCOLDº range depending on the fluid temperature.
See page 350 for additional information.
Exhaust system
If you notice any change in the sound of the exhaust or smell
exhaust fumes, have the cause located and corrected
immediately. (See ªEngine exhaust cautionº on page 233 in
Section 3±1.)
Vehicle interior
Items
listed below should be checked regularly, e.g. while
performing periodic services, cleaning the vehicle, etc.
Lights
Make sure the headlight, stop lights, tail lights, turn signal
lights, and other lights are working. Check headlight aim.
Service reminder indicators and warning buzzers
Check that all service reminder indicators and warning
buzzers function properly. Steering wheel
Check that it has the specified free play. Be alert for changes
in steering condition, such as hard steering, excessive free
play or strange noise.
Seats
Check that all front seat controls such as seat adjusters,
seatback recliner, etc. operate smoothly. Check that the head
restraints
move up and down smoothly and that the locks hold
securely in any latched position. For folding±down rear
seatbacks, check that the latches lock securely.
Seat belts
Check that the seat belt system such as buckles, retractors
and anchors operate properly and smoothly. Make sure the
belt webbing is not cut, frayed, worn or damaged.
Accelerator pedal
Check the pedal for smooth operation and uneven pedal ef fort
or catching.
Clutch pedal
Check the pedal for smooth operation.
Brake pedal
Check the pedal for smooth operation and the proper
clearance and freeplay. Check the brake booster function.
Brakes
In a safe place, check that the brakes do not pull to one side
when applied.
04 06.30

CHASSIS
373
REPLACING WHEELS
When to replace your wheels
If you have wheel damage such as bends, cracks or heavy
corrosion, the wheel should be replaced.
If you fail to replace a damaged wheel, the tire may slip off the
wheel or cause loss of handling control.
Replacement with used wheels is not recommended as they
may have been subjected to rough treatment or high mileage
and could fail without warning. Also, bent wheels which have
been straightened may have hidden structural damage and
therefore should not be used. Never use an inner tube in a
leaking wheel which is designed for a tubeless tire.
Wheel selection
When replacing wheels, care should be taken to ensure
that they are equivalent to those removed in load capacity,
diameter, rim width, and offset.
Correct replacement wheels are available at your Lexus
dealer.
A wheel of a different size or type may adversely affect
handling, wheel and bearing life, brake cooling,
speedometer/odometer calibration, stopping ability, headlight
aim, bumper height, vehicle ground clearance, and tire or snow
chain clearance to the body and chassis.
CAUTION
Observe the following instructions. Otherwise, an
accident may occur resulting in death or serious
injuries.
Do not use wheels other than the manufacturer's
recommended size, as this may cause dangerous
handling characteristics resulting in loss of control.
04 06.30