2003 Lexus IS300 warning

STARTING AND DRIVING
250
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!
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 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 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 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:
2003 IS300 from Aug. '02 Prod. (OM53439U)

STARTING AND DRIVING
252ºABSº 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
skid 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 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 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.
2003 IS300 from Aug. '02 Prod. (OM53439U)

STARTING AND DRIVING
253
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 ºABS
warning lightº on page 50 and ºVehicle skid control system
failure warningº on page 248.
2003 IS300 from Aug. '02 Prod. (OM53439U)

STARTING AND DRIVING
254
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.
TYPES OF TIRES
Determine w hat kind of tires your vehicle is originally equipped
with.
1. Summer tires
Summer tires are high±speed capability tires best suited to
highway driving under dry conditions.
Since summer tires do not have the same traction performance
as snow tires, summer tires are inadequate for driving on
snow±covered or icy roads. For driving on snow±covered or
icy roads, we recommend using snow tires. If installing snow
tires, be sure to replace all four tires.
2. All season tires
All season tires are designed to provide better traction in snow
and to be adequate for driving in most winter conditions, as well
as for use all year round.
All season tires, however, do not have adequate traction
performance compared with snow tires in heavy or loose snow.
Also, all season tires fall short in acceleration and handling
performance compared with summer tires in highway driving.
2003 IS300 from Aug. '02 Prod. (OM53439U)

IN CASE OF AN EMERGENCY
269
Warning: Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.
NOTICE
The battery used for boosting must be 12 V. Do not jumpstart unless you are sure that the booster battery iscorrect.
SV04019

5Discharged battery 6Booster battery
JUMP STARTING PROCEDURE
1. If the booster battery is installed in another vehicle, make
sure the vehicles are not touching. Turn off all unnecessary
lights and accessories.
2003 IS300 from Aug. '02 Prod. (OM53439U)

MAINTENANCE
294Tire rotation
Rotate the tires according to the maintenance schedule. (For
scheduled maintenance information, please refer to the
ªOwner's Manual Supplementº or ªScheduled Maintenanceº.)
See page 333 for additional information.
Fluid leaks
Check under
neath for leaking fuel, oil, water or other fluid after
the vehicle has been parked for a while. If you smell fuel fumes
or notice any leak, have the cause found and corrected
immediately.
Doors and engine hood
Check that all doors, including trunk lid or back door, operate
smoothly and all latches lock securely. Make sure the engine
hood secondary latch secures the hood when the primary latch
is released.
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. Ch
eck 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 free play. Check the brake booster function.
Brakes
At a safe place, check that the brakes do not pull to one side
when applied.
2003 IS300 from Aug. '02 Prod. (OM53439U)

INTRODUCTION
302
DO±IT±YOURSELF SERVICEPRECAUTIONS
If you perform maintenance yourself, be sure to follow the
correct procedure given in this Section.
You should be aware that improper or incomplete servicing
may result in operating problems.
Performing do±it±yourself maintenance during the warranty
period may affect your warranty coverage. Read the separate
Lexus Warranty statement for details and suggestions.
This Section gives instructions only for those items that are
relatively easy for an owner to perform. As explained in
Section 5, there are still a number of items that must be
performed by a qualified technician with special tools.
For information on tools and parts for do±it±yourself
maintenance, see ºParts and toolsº on page 303.
Utmost care should be taken when working on your vehicle to
prevent accidental injury. Here are a few precautions that you
should be especially careful to observe:
CAUTION

When the engine is running, keep hands, clothing,
and tools away from the moving fan and engine drive
belt. (Removing rings, watches, and ties is
advisable.)

Right after driving, the engine compartment ± the
engine, radiator, exhaust manifold and power
steering fluid reservoir, etc. ± will be hot. So be
careful not to touch them. Oil and other fluids may
also be hot.

Do not smoke, cause sparks or allow open flames
around fuel or the battery. Their fumes are
flammable.

Do not get under your vehicle with just the body jack
supporting it. Always use automotive jack stands or
other solid supports.

Be sure the ignition is off if you work near the electric
cooling fan or radiator grille. With the ignition on, the
electric cooling fan may automatically start to run if
the air conditioning is on and/or if the coolant
temperature is high.

Use eye protection whenever you work on or under
your vehicle where you may be exposed to flying or
falling material, fluid spray, etc.

Be extremely cautious when working on the battery.
It contains poisonous and corrosive sulfuric acid.

Warning: Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.
2003 IS300 from Aug. '02 Prod. (OM53439U)

CHASSIS
337
Warning: The traction grade assigned to this tire is based on
braking (straight ahead) traction tests and does not include
cornering (turning) traction.
Temperature A, B, C ± The temperature grades are A (the
highest), B, and C, representing the tire's resistance to the
generation of heat and its ability to dissipate heat when tested
under controlled conditions on a specified indoor laboratory
test wheel. Sustained high temperature can cause the
material of the tire to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire failure. The
grade C corresponds to a level of performance which all
passenger car tires must meet under the Federal Motor
Vehicle Safety Standard No. 109. Grades B and A represent
higher
levels of performance on the laboratory test wheel than
the minimum required by law.
Warning: The temperature grades for this tire are established
for a tire that is properly inflated and not overloaded.
Excessive speed, underinflation, or excessive loading, either
separately or in combination, can cause heat buildup and
possible tire failure.
Tire selection
When replacing a tire, use a tire of the same size and
construction, and the same or g reater load capacity as the
originally installed tires.
Using any other size or type of tire may seriously affect
handling, ride, speedometer/odometer calibration, ground
clearance, and clearance between the body and tires or snow
chains.
CAUTION
Observe the following instructions. Otherwise, an
accident may occur resulting in death or serious
injuries.
 Do not mix radial, bias belted, or bias±ply tires on
your vehicle, as this may cause dangerous handling
characteristics resulting in loss of control.
 Do not use tires other than the manufacturer's
recommended size, as this may cause dangerous
handling characteristics resulting in loss of control.
If you need to change from conventional tires to radial tires or
vice versa, replace them as a set.
2003 IS300 from Aug. '02 Prod. (OM53439U)