2004 TOYOTA SIENNA ignition

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The threeway catalytic converter is an
emission control device installed in the
exhaust system.
The purpose is to reduce pollutants in the
exhaust gas.
CAUTION
Keep people and combustible mate-
rials away from the exhaust pipe
while the engine is running. The
exhaust gas is very hot.
Do not drive, idle or park your ve-
hicle over anything that might burn
easily such as grass, leaves, paper
or rags.
NOTICE
A large amount of unburned gases
flowing into the threeway catalytic
converter may cause it to overheat
and create a fire hazard. To prevent
this and other damage, observe the
following precautions:
Use only unleaded gasoline.
 Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three
way catalytic converter.
 Do not allow the engine to run at
idle speed for more than 20 min-
utes.
 Avoid racing the engine.
 Do not pushstart or pullstart your
vehicle.
 Do not turn off the ignition while
the vehicle is moving.
Keep your engine in good running
order. Malfunctions in the engine
electrical system, electronic ignition
system/distributor ignition system
or fuel system could cause an ex-
tremely high threeway catalytic
converter temperature.
 If the engine becomes difficult to
start or stalls frequently, take your
vehicle in for a checkup as soon
as possible. Remember, your Toyota
dealer knows your vehicle and its
threeway catalytic converter sys-
tem best.
 To ensure that the threeway cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.
Threeway catalytic converter

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Ty p e A
Ty p e B
“ABS” warning light
Vehicles without the vehicle stability
control system—
The light comes on when the ignition key
is turned to the “ON” position. If the anti−
lock brake system works properly, the
light turns off after a few seconds. There-
after, if either of the systems malfunc-
tions, 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 does not operate,
but the brake system still operates con-
ventionally.
When the “ABS” warning light is on (and
the brake system warning light is off), the
anti −lock brake system does not operate
but the brake assist system still operates.
In this case 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 moni-
tored by the warning light system. Con-
tact 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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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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Before making these checks, make sure
you have followed the correct starting pro-
cedure given in “How to start the engine”
on page 394 in Section 3 and that you
have sufficient fuel. If your vehicle is
equipped with the engine immobilizer sys-
tem, also check whether the other keys
will start the engine. If they work, your
key may be broken. Have the key
checked at your Toyota dealer. If none of
your keys work, there may be a malfunc-
tion in the immobilizer system. Call your
Toyota dealer. (See “Keys (with engine
immobilizer system)” on page 10 in Sec-
tion 1−2.)
If the engine is not turning over or is
turning over too slowly— 1. Check that the battery terminals are tight and clean.
2. If the battery terminals are O.K., switch on the interior light.
3. If the light is out, dim or goes out when the starter is cranked, the battery
is discharged. You may try jump start-
ing. See “(c) Jump starting” on page
407 for further instructions.
If the light is O.K., but the engine still will
not start, it needs adjustment or repair.
Call a Toyota dealer or qualified repair
shop.NOTICE
Do not pull or pushstart the ve-
hicle. It may damage the vehicle or
cause a collision when the engine
starts. Also the threeway catalytic
converter may overheat and become a
fire hazard.
If the engine turns over at its normal
speed but will not start—
1. Turn the ignition key to “ACC” or “LOCK” and try starting the engine
again.
2. If the engine will not start, the engine may be flooded because of repeated
cranking. See “(b) Starting a flooded
engine” on page 406 for further instruc-
tions.
3. If the engine still will not start, it needs adjustment or repair. Call a Toyota
dealer or qualified repair shop. If the engine will not start, your engine
may be flooded because of repeated
cranking.
If this happens, turn the key to “START”
with the accelerator pedal fully depressed.
Keep the key and accelerator pedal in
these positions for 15 seconds and re-
lease them. Then try starting the engine
with your foot off the accelerator pedal.
If the engine does not start after 15 se-
conds of cranking, release the key, wait
a few minutes and try again.
If the engine still will not start, it needs
adjustment or repair. Call a Toyota dealer
or qualified repair shop for assistance.
NOTICE
Do not crank for more than 30 se-
conds at a time. This may overheat
the starter and wiring systems.
If your vehicle will not start—
(a) Simple checks
(b) Starting a flooded engine

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5. Start your engine in the normal way.After starting, run it at about 2000 rpm
for several minutes with the accelerator
pedal lightly depressed.
6. Carefully disconnect the cables in the exact reverse order: the negative cable
and then the positive cable.
7. Carefully dispose of the battery cover cloths—they may now contain sulfuric
acid.
8. If removed, replace all the battery vent plugs.
If the cause of your battery discharging is
not apparent (for example, lights left on),
you should have it checked at your Toyota
dealer.
If the first start attempt is not success-
ful...
Check that the clamp on the jumper
cables are tight. Recharge the discharged
battery with the jumper cables connected
for several minutes and restart your en-
gine in the normal way.
If the another attempt is not successful,
the battery may be depleted. Have it ch-
ecked at your Toyota dealer. If your engine stalls while driving...
1. Reduce your speed gradually, keeping a straight line. Move cautiously off the
road to a safe place.
2. Turn on your emergency flashers.
3. Turn the ignition key to “ACC” or “LOCK”, and try starting the engine
again.
If the engine will not start, see “If your
vehicle will not start” on page 406 in this
Section.
CAUTION
If the engine is not running, the pow-
er assist for the brakes and steering
will not work so steering and braking
will be much harder than usual.
If engine speed does not increase when
the accelerator pedal is depressed, there
may be a problem somewhere in the elec-
tronic throttle control system.
At this time, vibration may occur. Howev-
er, if you depress the accelerator pedal
more firmly and slowly, you can drive your
vehicle at low speeds. Have your vehicle
checked by your Toyota dealer as soon as
possible.
Even if the abnormality of the electronic
throttle control system is corrected during
low speed driving, the system may not be
recovered until the engine is stopped and
the ignition key is turned to “ACC” or
“LOCK” position.
CAUTION
Be especially careful to prevent erro-
neous pedal operation.
If your engine stalls while
driving If you cannot incr
ease engine
speed

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If your engine coolant temperature
gauge indicates overheating, if you ex-
perience a loss of power, or if you hear
a loud knocking or pinging noise, the
engine has probably overheated. You
should follow this procedure...1. Pull safely off the road, stop the ve- hicle and turn on your emergency
flashers. Put the transmission in “P”
and apply the parking brake. Turn off
the air conditioning if it is being used.
2. If coolant or steam is boiling out of the radiator or reservoir, stop the engine.
Wait until the steam subsides before
opening the hood. If there is no coolant
boiling over or steam, leave the engine
running and make sure the electric
cooling fan is operating. If it is not,
turn the ignition off.
CAUTION
To help avoid personal injury, keep
the hood closed until there is no
steam. Escaping steam or coolant is
a sign of very high pressure.
3. Look for obvious coolant leaks from theradiator, hoses, and under the vehicle.
However, note that water draining from
the air conditioning is normal if it has
been used.
CAUTION
When the engine is running, keep
hands and clothing away from the
moving fan and engine drive belts.
4. If the coolant is leaking, stop the en-gine immediately. Call a Toyota dealer
for assistance.
5. If there are no obvious leaks, check the coolant reservoir. If it is dry, add
coolant to the reservoir while the en-
gine is running. Fill it about half full.
CAUTION
Do not attempt to remove the radiator
cap when the engine and radiator are
hot. Serious injury could result from
scalding hot fluid and steam blown
out under pressure.
6. After the engine coolant temperaturehas cooled to normal, again check the
coolant level in the reservoir. If neces-
sary, bring it up to half full again. Seri-
ous coolant loss indicates a leak in the
system. You s hould have it checked as
soon as possible at your Toyota dealer.
If your vehicle overheats

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You can purchase a new key at your
Toyota dealer if you can give them the
key number. If your vehicle is equipped
with the engine immobilizer system, the
dealer will also need your master key.
Vehicles with engine immobilizer system—
Even if you lose only one key, contact
your Toyota dealer to make a new key. If
you lose all your master keys, you cannot
make new keys; the whole engine immobi-
lizer system must be replaced.
See the suggestion given in “Keys” on
page 10 in Section 1−2.
If your keys are locked in the vehicle and
you cannot get a duplicate, many Toyota
dealers can still open the door for you,
using their special tools. If you must
break a window to get in, we suggest
breaking the smallest side window be-
cause it is the least expensive to replace.
Be extremely cautious to avoid cuts from
the glass. Please contact your nearest Toyota
dealer and you can purchase a new
wireless remote control transmitter.
Have the registered identification numbers
of your transmitters deleted from your ve-
hicle by your Toyota dealer as soon as
possible to avoid the possibility of theft or
an accident. Then, have the identification
number of your new transmitter registered.
At the same time, you must bring all of
the remaining transmitters to have them
registered again as well.
You can use the wireless remote control
system with the new transmitter. Contact
your Toyota dealer for detailed information.
If you cannot shift the selector lever
out of “P” position to other positions
even though the brake pedal is de-
pressed, use the shift lock override but-
ton as follows:
1. Turn the ignition key to “LOCK” position. Make sure the parking
brake is applied.
2. Pry up the cover with a flatbladed screwdriver or equivalent.
If you lose your keys If you lose your wireless
remote control transmitterIf you cannot shift automatic
transmission selector lever

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If you perform maintenance by yourself,
be sure to follow the correct procedure
given in this Section.
You should be aware that improper or in-
complete servicing may result in operating
problems.
Performing do−it−yourself maintenance
during the warranty period may affect your
warranty coverage. Read the separate
Toyota 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
6, there are still a number of items that
must be done by a qualified technician
with special tools.
For information on tools and Sections for
do− it−yourself maintenance, see “Parts
and tools” on page 453 in this Section.
Utmost care should be taken when work-
ing on your vehicle to prevent accidental
injury. Here are a few precautions that
you should be especially careful to ob-
serve:CAUTION
When the engine is running, keep
hands, clothing, and tools away
from the moving fan and engine
drive belts. (Removing rings,
watches, and ties is advisable.)
Right after driving, the engine
compartment—the engine, radiator,
exhaust manifold and spark plug
boots, etc.—will be hot. So be care-
ful not to touch them. Oil, fluids
and spark plugs may also be hot.
If the engine is hot, do not remove
the radiator cap or loosen the drain
plugs to prevent burning yourself.
Do not leave anything that may
burn easily, such as paper or rags,
in the engine compartment.
Do not smoke, cause sparks or al-
low open flames around fuel or the
battery. Their fumes are flammable.
Do not get under your vehicle with
just the body jack supporting it. Al-
ways use automotive jack stands or
other solid supports.
Be sure that the ignition is off if
you work near the electric cooling
fans or radiator grille. With the
ignition on, the electric cooling fans
will automatically start to run if the
engine coolant temperature is high
and/or the air conditioning is on.
Use eye protection whenever you
work on or under your vehicle
where you may be exposed to flying
or falling material, fluid spray, etc.
Used engine oil contains potentially
harmful contaminants which may
cause skin disorders such as in-
flammation or skin cancer, so care
should be taken to avoid prolonged
and repeated contact with it. To re-
move used engine oil from your
skin, wash thoroughly with soap
and water.
Do not leave used oil within the
reach of children.
Dispose of used oil and filter only
in a safe and acceptable manner.
Do not dispose of used oil and fil-
ter in household trash, in sewers or
onto the ground. Call your dealer or
a service station for information
concerning recycling or disposal.
Doityourself service
precautions