2003 TOYOTA SIENNA warning light

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The tandem master cylinder brake system
is a hydraulic system with two separate
subsystems. If either subsystem 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
powerassist 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 vacu-
um.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push the
pedal hard, much harder than nor-
mal. And your braking distance will
be longer.
ANTILOCK BRAKE SYSTEM (with
“ABS” warning light)
The antilock brake system is designed
to help prevent lockup of the wheels
during a sudden braking or braking on
slippery road surfaces. This assists in
providing directional stability and steer-
ing performance of the vehicle under
these circumstances.
Effective way to press the ABS brake
pedal: When the antilock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the antilock
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 performan-
ce.
The antilock brake system becomes op-
erative 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 construc-
tion, joints in the bridge, etc. on a rainy
day tends to activate the antilock 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
antilock brake system is in the self
check mode, and does not indicate a mal-
function.
Brake system

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Ty p e A
Ty p e B
“ABS” warning light
The light comes on when the ignition key
is turned to the “ON” position. If the anti
lock brake system and the brake assist
system work properly, the light turns off
after a few seconds. Thereafter, if either
of the systems malfunctions, the light
comes on again.
When the “ABS” warning light is on (and
the brake system warning light is off), the
antilock brake system, the brake assist
system, the traction control system and
the vehicle skid control system do not
operate, but the brake system still oper-
ates conventionally.
When the “ABS” warning light is on (and
the brake system warning light is off), the
antilock brake system 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
Toyota dealer as soon as possible to
service the vehicle.
The light does not come on when the
ignition key is turned to the “ON” posi-
tion, or remains on.
The light comes on while you are driv-
ing.
A warning light turning on briefly during
operation does not indicate a problem.
CAUTION
If the “ABS” warning light remains on
together with the brake system warn-
ing light, immediately stop your ve-
hicle at a safe place and contact your
Toyota dealer.
In this case, not only the antilock
brake system will fail but also the
vehicle will become extremely unsta-
ble during braking.

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BRAKE ASSIST SYSTEM
When you slam the brakes on, the
brake assist system judges as an emer-
gency stop and provides more powerful
braking for a driver who cannot hold
down the brake pedal firmly.
When you slam the brakes on, more pow-
erful 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 mal-
function.
The brake assist system becomes opera-
tive 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 warn-
ing light, see “Service reminder indicators
and warning buzzers” in Section 15.
The brake pad wear limit indicators on
your disc brakes give a warning noise
when the brake pads are worn to where
replacement is required.
If you hear a squealing or scraping noise
while driving, have the brake pads
checked and replaced by your Toyota
dealer as soon as possible. Expensive ro-
tor damage can result if the pads are not
replaced when necessary.When stowing luggage or cargo in the
vehicle, observe the following:
Put luggage or cargo in the luggage
compartment when at all possible. Be
sure all items are secured in place.
Be careful to keep the vehicle bal-
anced. Locating the weight as far for-
ward as possible helps maintain bal-
ance.
For better fuel economy, do not carry
unneeded weight.
CAUTION
To prevent luggage or packages
from sliding forward during braking,
do not stack anything in the lug-
gage compartment higher than the
seatbacks. Keep luggage or pack-
ages low, as close to the floor as
possible.
Never allow anyone to ride in the
luggage compartment. It is not de-
signed for passengers. They should
ride in their seats with their seat
belts properly fastened. Otherwise,
they are much more likely to suffer
serious bodily injury, in the event
of sudden braking or a collision.
Brake pad wear limit
indicators
Luggage stowage pr
ecautions

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To avoid serious personal injury and
damage to your vehicle which might re-
sult from battery explosion, acid burns,
electrical burns, or damaged electronic
components, these instructions must be
followed precisely.
If you are unsure about how to follow this
procedure, we strongly recommend that
you seek the help of a competent me-
chanic or towing service.
CAUTION
Batteries contain sulfuric acid
which is poisonous and corrosive.
Wear protective safety glasses when
jump starting, and avoid spilling
acid on your skin, clothing, or ve-
hicle.
If you should accidentally get acid
on yourself or in your eyes, remove
any contaminated clothing and flush
the affected area with water imme-
diately. Then get immediate medical
attention. If possible, continue to
apply water with a sponge or cloth
while en route to the medical office.
The gas normally produced by a
battery will explode if a flame or
spark is brought near. Use only
standardized jumper cables and do
not smoke or light a match while
jump starting.
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 jump start unless you
are sure that the booster battery is
correct.
JUMP STARTING PROCEDURE1. If the booster battery is installed in another vehicle, make sure the vehicles
are not touching. Turn off all unneces-
sary lights and accessories.
2. If required, remove all the vent plugs from the booster and discharged batter-
ies. Lay a cloth over the open vents
on the batteries. (This helps reduce the
explosion hazard, personal injuries and
burns.)
3. If the engine in the vehicle with the booster battery is not running, start it
and let it run for a few minutes. During
jump starting, run the engine at about
2000 rpm with the accelerator pedal
lightly depressed.
(c) Jump starting

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Lights
Make sure the headlights, stop lights, tail
lights, turn signal lights, and other lights
are all working. Check headlight aim.
Service reminder indicators and warning
buzzers
Check that all service reminder indicators
and warning buzzers function properly.
Steering wheel
Be alert for changes in steering condition,
such as hard steering or strange noise.
Seats
Check that all seat controls such as seat
adjusters, seatback recliner, etc. operate
smoothly and that all latches lock securely
in any position. Check that the head re-
straints move up and down smoothly and
that the locks hold securely in any latched
position. For foldingdown rear seatbacks
and detachable rear seats, 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 dam-
aged.Accelerator pedal
Check the pedal for smooth operation and
uneven pedal effort or catching.
Brake pedal
Check the pedal for smooth operation and
that the pedal has the proper clearance.
Check the brake booster function.
Brakes
At a safe place, check that the brakes do
not pull to one side when applied.
Parking brake
Check that the pedal has the proper travel
and that, on a safe incline, your vehicle
is held securely with only the parking
brake applied.
Automatic transmission “Park” mecha-
nism
On a safe incline, check that your vehicle
is held securely with the selector lever in
“P” position and all brakes released.
IN THE ENGINE COMPARTMENT
Items listed below should be checked
from time to time, e.g. each time when
refueling.
Washer fluid
Make sure there is sufficient fluid in the
tank. See Section 73 for additional in-
formation.
Engine coolant level
Make sure the coolant level is between
the “FULL” and “LOW” lines on the see
through reservoir when the engine is cold.
See Section 72 for additional information.
Radiator, condenser and hoses
Check that the front of the radiator and
condenser are clean and not blocked with
leaves, dirt, or insects. See Section 72
for additional information.
Battery electrolyte level
Your Toyota has a maintenance free bat-
tery. You do not have to add distilled wa-
ter. For longer life of the battery, however,
see Section 73 for additional information.
Brake fluid level
Make sure the brake fluid level is correct.
See Section 72 for additional information.

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Avoid sharp turns or lockedwheel
braking, as use of chains may ad-
versely affect vehicle handling.
When driving with chains installed,
be sure to drive carefully. Slow
down before entering the curves to
avoid losing control of the vehicle.
Otherwise an accident may occur.
NOTICE
Do not attempt to use a tire chain on
the compact spare tire, as it may re-
sult in damage to the vehicle as well
as the tire.
WHEN TO REPLACE YOUR WHEELS
If you have wheel damage such as
bending, cracks or heavy corrosion, the
wheel should be replaced.
If you fail to replace damaged wheels, the
tire may slip off the wheel or cause loss
of handling control.
WHEEL SELECTION
When replacing wheels, care should be
taken to ensure that the wheels are re-
placed by ones with the same load ca-
pacity, diameter, rim width, and offset.
This must be observed on compact spare
tires, too.
Correct replacement wheels are available
at your Toyota dealer.
A wheel of a different size or type may
adversely affect handling, wheel and bear-
ing life, brake cooling, speedometer/odom-
eter calibration, stopping ability, headlight
aim, bumper height, vehicle ground clear-
ance, and tire or snow chain clearance to
the body and chassis. Replacement with used wheels is not rec-
ommended as they may have been sub-
jected to rough treatment or high mileage
and could fail without warning. Also, bent
wheels which have been straightened may
have structural damage and therefore
should not be used. Never use an inner
tube in a leaking wheel which is designed
for a tubeless tire.
CAUTION
Do not use wheels other than the
manufacturer ’s recommended size, as
this may cause dangerous handling
characteristics resulting in loss of
control. Otherwise, an accident may
occur resulting in death or serious
injuries.
Initial adjustment of the tire pressure
warning system is necessary after you
have replaced your wheels. See “Tire
pressure warning system” in Section
16.
Replacing wheels

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CAUTION
BATTERY PRECAUTIONS
The battery produces flammable and
explosive hydrogen gas.
Do not cause a spark from the bat-
tery with tools.
Do not smoke or light a match near
the battery.
The electrolyte contains poisonous
and corrosive sulfuric acid.
Avoid contact with eyes, skin or
clothes.
Never ingest electrolyte.
Wear protective safety glasses when
working near the battery.
Keep children away from the bat-
tery.
EMERGENCY MEASURES
If electrolyte gets in your eyes,
flush your eyes with clean water
immediately and get immediate
medical attention. If possible, con-
tinue to apply water with a sponge
or cloth while en route to the medi-
cal office.
If electrolyte gets on your skin,
thoroughly wash the contact area. If
you feel pain or burning, get medi-
cal attention immediately.
If electrolyte gets on your clothes,
there is a possibility of its soaking
through to your skin, so immediate-
ly take off the exposed clothing and
follow the procedure above, if nec-
essary.
If you accidentally swallow electro-
lyte, drink a large quantity of water
or milk. Follow with milk of magne-
sia, beaten raw egg or vegetable
oil. Then go immediately for emer-
gency help.
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.
Holddown
clamp
Ground
cableTerminals
Check the battery for corroded or loose
terminal connections, cracks, or loose
holddown clamp. a. If the battery is corroded, wash it off with a solution of warm water and bak-
ing soda. Coat the outside of the termi-
nals with grease to prevent further cor-
rosion.
b. If the terminal connections are loose, tighten their clamp nuts—but do not
overtighten.
c. Tighten the holddown clamp only enough to keep the battery firmly in
place. Overtightening may damage the
battery case.
Checking battery c ondition—
—Precautions —Checking battery exterior

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If the new fuse immediately blows out,
there is a problem with the electrical sys-
tem. Have your Toyota dealer correct it as
soon as possible.
CAUTION
Never use a fuse with a higher am-
perage rating, or any other object, in
place of a fuse. This may cause ex-
tensive damage and possibly a fire.
If any washer does not work or low
windshield washer fluid level warning
light comes on, the washer tank may be
empty. Add washer fluid.
You may use plain water as washer fluid.
However, in cold areas where tempera-
tures range below freezing point, use
washer fluid containing antifreeze. This
product is available at your Toyota dealer
and most auto parts stores. Follow the
manufacturer ’s directions for how much to
mix with water.
NOTICE
Do not use engine antifreeze or any
other substitute because it may dam-
age your vehicle’s paint.
The following illustrations show how to
gain access to the bulbs. When replacing
a bulb, make sure the ignition switch and
light switch are off. Use bulbs with the
wattage ratings given in the table.
CAUTION
To prevent yourself from burning,
do not replace the light bulbs while
they are hot.
Halogen bulbs have pressurized gas
inside and require special handling.
They can burst or shatter if
scratched or dropped. Hold a bulb
only by its plastic or metal case.
Do not touch the glass part of a
bulb with bare hands.
NOTICE
Only use a bulb of the listed type.
Adding washer fluidReplacing light bulbs—