2003 TOYOTA SIENNA check engine

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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”
in Section 3 and that you have sufficient
fuel. If your vehicle is equipped with the
engine immobiliser system, also check
whether the other keys will start the en-
gine. If they work, your key may be bro-
ken. Have the key checked at your Toyota
dealer. If none of your keys work, the
system is possibly broken. Call your
Toyota dealer. (See “Keys (with engine
immobiliser system)” in Section 12.)
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” 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 does not start, check that all the pushon connectors are tight.
(For example, connectors at the spark
plugs, ignition coil and/or distributor)
3. If the connectors are O.K., the engine may be flooded because of repeated
cranking. See “(b) Starting a flooded
engine” for further instructions. 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 held down.
Keep the key and accelerator pedal these
positions for 15 seconds and release
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 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”.
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 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.
If your engine stalls while
driving If your vehicle overheats

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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. 1. Reduce your speed gradually, keeping
a straight line. Move cautiously off the
road to a safe place well away from
the traffic. Avoid stopping on the center
divider of a highway. Park on a level
spot with firm ground.
2. Stop the engine and turn on your emergency flashers.
3. Firmly set the parking brake and put the transmission in “P”.
4. Have everyone get out of the vehicle on the side away from traffic.
5. Read the following instructions thor- oughly.
CAUTION
When jacking, be sure to observe the
following to reduce the possibility of
personal injury:
Follow jacking instructions.
Do not put any part of your body
under the vehicle supported by the
jack. Otherwise, personal injury may
occur.
Do not start or run the engine while
your vehicle is supported by the
jack.
If you have a flat tire—

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If you are a skilled doityourself mechan-
ic, the Toyota service manuals are recom-
mended. Please be aware that doityour-
self maintenance can affect your warranty
coverage. See “Owner ’s Warranty Informa-
tion Booklet” or “Owner ’s Manual Supple-
ment” for the details.Listed below are the general maintenance
items that should be performed as fre-
quently as specified. In addition to check-
ing the items listed, if you notice any
unusual noise, smell or vibration, you
should investigate the cause or take your
vehicle to your Toyota dealer or a quali-
fied service shop immediately. It is recom-
mended that any problem you notice be
brought to the attention of your dealer or
the qualified service shop for their advice.
CAUTION
Make these checks only where ade-
quate ventilation can be obtained if
you run the engine.
OUTSIDE THE VEHICLE
Items listed below should be performed
from time to time, unless otherwise
specified.
Tire pressure
Check the pressure with a gauge every
two weeks, or at least once a month. See
Section 72 for additional information.Tire surface and wheel nuts
Check the tires carefully for cuts, damage
or excessive wear. See Section 72 for
additional information. When checking the
tires, make sure no nuts are missing, and
check the nuts for looseness. Tighten
them if necessary.
Tire rotation
Rotate the tires according to the mainte-
nance schedule. (For scheduled mainte-
nance information, please refer to the
“Scheduled Maintenance Guide” or “Own-
er ’s Manual Supplement”.) See Section
72 for additional information.
Fluid leaks
Check underneath for leaking fuel, oil, wa-
ter 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 the doors operate smoothly
and all latches lock securely. Make sure
the engine hood secondary latch secures
the hood from opening when the primary
latch is released.
INSIDE THE VEHICLE
Items listed below should be checked
regularly, e.g. while performing periodic
services, cleaning the vehicle, etc.
General maintenance

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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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Engine oil level
Check the level on the dipstick with the
engine turned off and the vehicle parked
on a level spot. See Section 72 for addi-
tional information.
Power steering fluid level
Check the level through the reservoir. The
level should be in the “HOT” or “COLD”
range depending on the fluid temperature.
See Section 72 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 immedi-
ately. (See “Engine exhaust cautions” in
Section 2.)Be on the alert for changes in perfor-
mance, sounds, and visual tipoffs that
indicate service is needed. Some impor-
tant clues are as follows:
Engine missing, stumbling, or pinging
Appreciable loss of power
Strange engine noises
A leak under the vehicle (however, wa-
ter dripping from the air conditioning
after use is normal.)
Change in exhaust sound (This may
indicate a dangerous carbon monoxide
leak. Drive with the windows open and
have the exhaust system checked im-
mediately.)
Flatlooking tire; excessive tire squeal
when cornering; uneven tire wear
Vehicle pulls to one side when driving
straight on a level road
Strange noises related to suspension
movement
Loss of brake effectiveness; spongy
feeling brake pedal; pedal almost
touches floor; vehicle pulls to one side
when braking
Engine coolant temperature continually
higher than normalIf you notice any of these clues, take your
vehicle to your Toyota dealer as soon as
possible. It probably needs adjustment or
repair.
CAUTION
Do not continue driving with the ve-
hicle unchecked. It could result in se-
rious vehicle damage and possibly
personal injury.
Does your vehicle need
repairing?

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Be extremely cautious when work-
ing on the battery. It contains poi-
sonous 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.
NOTICE
Remember that battery and ignition
cables carry high currents or volt-
ages. Be careful of accidentally
causing a short circuit.
 Add only demineralized or distilled
water to fill the radiator. And if you
spill some of the coolant, be sure
to wash off with water to prevent it
from damaging the parts or paint.
 Do not allow dirt or anything else
to fall through the spark plug holes.
 Do not pry the outer electrode of a
spark plug against the center elec-
trode.
Use only spark plugs of the speci-
fied type. Using other types will
cause engine damage, loss of per-
formance or radio noise.
 Do not reuse iridiumtipped spark
plugs by cleaning or regapping.
 Do not overfill automatic transmis-
sion fluid and power steering fluid,
or the transmission and power
steering could be damaged.
 Do not drive with the air cleaner
filter removed, or excessive engine
wear could result. Also backfiring
could cause a fire in the engine
compartment.
 Be careful not to scratch the glass
surface with the wiper frame.
 When closing the engine hood,
check to see that you have not for-
gotten any tools, rags, etc.Front
Do not jack up
Positioning the jack

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When jacking up your vehicle with the
jack, position the jack correctly as
shown in the illustrations.
CAUTION
When jacking, be sure to observe the
following to reduce the possibility of
personal injury:
Follow jacking instructions.
Do not put any part of your body
under the vehicle supported by the
jack. Personal injury may occur.
Do not start or run the engine while
your vehicle is supported by the
jack.
Stop the vehicle on a level firm
ground, firmly set the parking brake
and put the transmission in “P”.
Block the wheels on the opposite
side of the jack up point if neces-
sary.
Make sure to set the jack properly
in the jack point. Raising the ve-
hicle with jack improperly posi-
tioned will damage the vehicle or
may allow the vehicle to fall off the
jack and cause personal injury.
Never get under the vehicle when
the vehicle is supported by the jack
alone; use vehicle support stands.
Do not raise the vehicle with some-
one in the vehicle.
When raising the vehicle, do not
put an object on or under the jack.
NOTICE
Make sure to place the jack correctly,
or your vehicle may be damaged.
Here is a list of parts and tools you will
need on performing doityourself mainte-
nance. Remember all Toyota parts are de-
signed in metric sizes, so your tools must
be metric.
CHECKING THE ENGINE OIL LEVEL
Parts (if level is low):
“Toyota Genuine Motor Oil” or equiva-
lent
See Section 72 for details about en-
gine oil selection.
Tools:
Rag or paper towel
Funnel (only for adding oil)
CHECKING THE ENGINE COOLANT
LEVEL
Parts (if level is low):
“Toyota Genuine Long Life Coolant” or
equivalent
See Section 72 for details about cool-
ant type selection.
Demineralized or distilled water
Tools:
Funnel (only for adding coolant)
Parts and tools