2004 TOYOTA SIENNA traction control

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2004 SIENNA from Aug. ’04 Prod. (OM45422U)
“TRAC OFF” indicator light comes on for
a few seconds when the ignition key is
turned to “ON”. It will come on again
when you push the “TRAC OFF” switch to
turn off the system.
In the following cases, contact your Toyota
dealer:
The indicator light does not come on
when the ignition key is turned “ON”.
The indicator light remains on after the
ignition is turned on.
The indicator light comes on with the
normal driving mode while driving.
“VSC” warning light
This light warns that there is a problem
somewhere in the traction control system
or the vehicle stability control system.
The light will come on when the ignition
key is turned to “ON” and will go off after
a few seconds.
If the light comes on while driving, the
system does not work. However, as con-
ventional braking operates when applied,
there is no problem to continue your driv-
ing.In the following cases, contact your Toyota
dealer:
The warning light does not come on
after the ignition key is turned to “ON”.
The warning light remains on after the
ignition key is turned to “ON”.
The warning light comes on while driv-
ing.
The “TRAC OFF” indicator light will come
on when the “VSC” warning light comes
on even if the “TRAC OFF” switch is not
pushed.

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The traction control system automatical-
ly helps prevent the spinning of 4
wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the ignition key is turned to “ON”,
the system automatically turns on.
CAUTION
Under certain slippery road condi-
tions, full traction of the vehicle and
power against 4 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 may
cause the vehicle to lose traction
control. 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
speed for the present road condi-
tions.
NORMAL DRIVING MODE
Leave the system on during the ordi-
nary driving so that it can operate
when needed.
You may hear a sound in the engine
compartment for a few seconds just after
the vehicle begins to move. This means
that the traction control system is in the
self−check mode, but does not indicate a
malfunction. When the traction control system is oper-
ating, the following conditions occur:
The system controls the spinning of the
4 wheels. At this time, the slip indica-
tor light blinks.
You may feel vibration or noise in your
vehicle, caused by operation of the
brakes. This indicates the system is
functioning properly.
The slip indicator light comes on for a few
seconds when the ignition key is turned
to “ON”. If the indicator light does not
come on when the ignition is turned on,
contact your Toyota dealer.
Traction control system
(allwheel drive models)

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2004 SIENNA from Aug. ’04 Prod. (OM45422U)
“VSC” warning light
This light warns that there is a problem
somewhere in the traction control system
or the vehicle stability control system.
The light will come on when the ignition
key is turned to “ON” and will go off after
a few seconds.
If the light comes on while driving, the
system does not work. However, as con-
ventional braking operates when applied,
there is no problem to continue your driv-
ing.In the following cases, contact your Toyota
dealer:
The warning light does not come on
after the ignition key is turned to “ON”.
The warning light remains on after the
ignition key is turned to “ON”.
The warning light comes on while driv-
ing.
The vehicle stability control system
helps provide integrated control of the
systems such as an antilock brake
system, brake assist system, traction
control, engine control, etc. This sys-
tem automatically controls the brakes
and engine to help prevent the vehicle
from skidding when cornering on a slip-
pery road surface or operating steering
wheel abruptly.
This system activates when the vehicle
speed is about more than 15 km/h (9
mph).
You may hear a sound in the engine
compartment for a few seconds just after
the vehicle begins to move. This means
that the system is in the self
−check mode,
but does not indicate a malfunction.
Vehicle stability control
system

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2004 SIENNA from Aug. ’04 Prod. (OM45422U)
CAUTION
Do not rely excessively on the ve-
hicle stability control system. Even
if the vehicle stability control sys-
tem is operating, you must always
drive carefully and attentively to
avoid serious injury. Reckless driv-
ing will result in an unexpected ac-
cident. If the slip indicator light
flashes, an alarm sounds, 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 stability control
system may not function correctly.
When replacing the tires or wheels,
contact your Toyota dealer. (See
“Checking and replacing tires” on
page 466 in Section 72.)
If the vehicle is going to skid during driv-
ing, the slip indicator light blinks and an
alarm sounds intermittently. Special care
should be taken while driving.
The slip indicator light comes on for a few
seconds when the ignition key is turned
to “ON”. If the indicator light does not
come on when the ignition is turned on,
contact your Toyota dealer.“VSC” warning light
This light warns that there is a problem
somewhere in the vehicle stability control
system or the traction control system.
The light will come on when the ignition
key is turned to “ON” and will go off after
a few seconds.
If the light comes on while driving, the
system does not work. However, as con-
ventional braking operates when applied,
there is no problem to continue your driv-
ing.

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Vehicles with the vehicle stability con-
trol system—
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
anti −lock brake system, the brake assist
system, the traction control system and
the vehicle stability 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
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 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.
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.
Vehicles with the vehicle stability control
system—
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” on page 167 in Sec-
tion 1 −5.

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This information has been prepared
in accordance with regulations issued
by the National Highway Traffic Safe-
ty Administration of the U.S. Depart-
ment of Transportation. It provides
the purchasers and/or prospective
purchasers of Toyota vehicles with in-
formation on uniform tire quality grad-
ing.
Your Toyota dealer will help answer
any questions you may have as you
read this information.
DOT quality grades—All passenger
vehicle tires must conform to Fed-
eral Safety Requirements in addi-
tion to these grades. Quality
grades can be found where appli-
cable on the tire sidewall between
tread shoulder and maximum sec-
tion width. For example: Treadwear
200 Traction AA Temperature ATreadwear—
The treadwear grade is
a comparative rating based on the
wear rate of the tire when tested un-
der controlled conditions on a speci-
fied government test course. For ex-
ample, a tire graded 150 would wear
one and a half (1 −1/2) times as well
on the government course as a tire
graded 100. The relative performance
of tires depends upon the actual
conditions of their use, however, and
may depart significantly from the
norm due to variations in driving hab-
its, service practices and differences
in road characteristics and climate. Traction AA, A, B, C—
The traction
grades, from highest to lowest, are
AA, A, B, and C, and they represent
the tire’s ability to stop on wet pave-
ment as measured under controlled
conditions on specified government
test surfaces of asphalt and concrete.
A tire marked C may have poor trac-
tion performance.
Warning: The traction grade assigned
to this tire is based on braking
(straight ahead) traction tests and
does not include cornering (turning)
traction.
—Uniform tire quality grading

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Determine what kind of tires your
vehicle is originally equipped with.1. Summer tires
Summer tires are high −speed capabil-
ity 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 pro-
vide 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.
The details about how to distinguish
summer tires from all season tires are
described on page 378.
CAUTION

Do not mix summer and all sea-
son tires on your vehicle as
this can cause dangerous han-
dling characteristics, resulting
in loss of control.
 Do not use tires other than the
manufacturer’s designated
tires, and never mix tires or
wheels of the sizes different
from the originally equipped
tires and wheels.
Types of tires

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Do not drive in excess of the speed
limit. Even if the legal speed limit
permits it, do not drive over 140
km/h (85 mph) unless your vehicle
has highspeed capability tires.
Driving over 140 km/h (85 mph) may
result in tire failure, loss of control
and possible injury. Be sure to con-
sult a tire dealer to determine
whether the tires on your vehicle
are highspeed capability tires or
not before driving at such speeds.
Do not continue normal driving
when the brakes are wet. If they are
wet, your vehicle will require a
longer stopping distance, and it
may pull to one side when the
brakes are applied. Also, the park-
ing brake will not hold the vehicle
securely.
If you need greater traction while driv-
ing on sand, mud or snow covered
roadways, use tire chains on the front
wheels.
Always check your brakes for effective-
ness immediately after driving across
sand, mud, or water.
If operating in adverse conditions
frequently, vehicle maintenance should
be increased. (See the separate
“Scheduled Maintenance Guide” or
“Owner ’s Manual Supplement”.)
CAUTION
Observe the following tire instruc-
tions. Otherwise, an accident may oc-
cur resulting in death or serious inju-
ries.
Keep your tire pressure at the prop-
er level. (See “Checking tire infla-
tion pressure” on page 463 in Sec-
tion 72.)
Do not use tires (including snow
tires) of different brands, sizes,
construction or tread patterns. (See
“Checking and replacing tires” on
page 466 and “Installing snow tires
and chains” on page 471 in Section
72.)
Do not use tires with different tread
wear. To equalize the tire wear, ro-
tate tires at the appropriate interval.
(See “Rotating tires” on page 468
in Section 72.)
Use the manufacturer ’s recom-
mended wheels. Do not use wheels
of different sizes and types. (See
“Replacing wheels” on page 473 in
Section 72.)
NOTICE
Do not attempt to go offroad in your
Toyota. It is not designed for offroad
use.
Allwheel driving tips
(AWD models)