2004 TOYOTA SIENNA service

04 SIENNA_U (L/O 0408)
443
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
If you are a skilled do−it−yourself mechan-
ic, the Toyota service manuals are recom-
mended. Please be aware that do −it−your-
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 with ade-
quate ventilation if you run the en-
gine.
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 page 479 in Section 7
−3 for
additional information. 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 page 458 in Section 7 −2 for addition-
al 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 page 460 in
Section 7 −2 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 page 476 in Section 7 −3 for additional
information.
Brake fluid level
Make sure the brake fluid level is correct.
See page 462 in Section 7 −2 for addition-
al information.
Engine oil level
Check the level on the dipstick with the
engine turned off and the vehicle parked
on a level spot. See page 456 in Section
7 −2 for additional information.
General maintenance

04 SIENNA_U (L/O 0408)
444
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
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 page 463 in Section 7−2 for addition-
al 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” on
page 370 in Section 2.)
INSIDE THE VEHICLE
Items listed below should be checked
regularly, e.g. while performing periodic
services, cleaning the vehicle, etc.
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 folding
−down rear seatbacks
and detachable second 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
In 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.
OUTSIDE THE VEHICLE
Items listed below should be performed
from time to time, unless otherwise
specified.
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 including back
door operate smoothly and all latches lock
securely. Make sure the engine hood sec-
ondary latch secures the hood from open-
ing when the primary latch is released.

04 SIENNA_U (L/O 0408)
445
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Tire inflation pressure
Check the pressure with a gauge ev-
ery two weeks, or at least once a
month. See page 463 in Section 7−2
for additional information.
Tire surface and wheel nuts
Check the tires carefully for cuts,
damage or excessive wear. See page
466 in Section 7− 2 for additional in-
formation. 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
maintenance schedule. (For sched-
uled maintenance information, please
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.) See page 468 in Section 7 −2
for additional information.Be on the alert for changes in perfor-
mance, sounds, and visual tip −offs 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.)
Flat −looking 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 normal If 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?

04 SIENNA_U (L/O 0408)
446
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Some states have vehicle emission in-
spection programs which include OBD
(On−Board Diagnostics) che cks.
The OBD system monitors the operation
of the emission control system. When the
OBD system determines that a problem
exists somewhere in the emission control
system, the malfunction indicator lamp
comes on. In this case, your vehicle may
not pass the I/M test and need to be
repaired. Contact your Toyota dealer to
service the vehicle.
Even if the malfunction indicator lamp
does not come on, your vehicle may not
pass the I/M test as readiness codes
have not been set in the OBD system.
Readiness codes are automatically set
during ordinary driving. However, when the
battery is disconnected or run down, the
codes are erased. Also, depending on
your driving habits, the codes may not be
completely set.
Also, if the malfunction indicator lamp had
come on recently due to temporary mal-
function such as a loose fuel tank cap,
your vehicle may not pass the I/M test. The malfunction indicator lamp will go off
after taking several driving trips, but the
error code in the OBD system will not be
cleared unless about 40 trips or more are
taken.
If your vehicle does not pass the I/M test
even the malfunction indicator lamp does
not come on, contact your Toyota dealer
to prepare the vehicle for re
−testing.
Emissions Inspection and
Maintenance (I/M) programs

04 SIENNA_U (L/O 0408)
447
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
DOITYOURSELF MAINTENANCE
Introduction
Engine compartment overview448
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuse locations 449
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . .
Do −it− yourself service precautions 450
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Positioning the jack 451
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . .
Parts and tools 453
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . .
SECTION 7 1

04 SIENNA_U (L/O 0408)
450
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
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

04 SIENNA_U (L/O 0408)
457
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Engine oil selection
“Toyota Genuine Motor Oil” is used in
your Toyota vehicle. Use Toyota approved
“Toyota Genuine Motor Oil” or equivalent
to satisfy the following grade and
viscosity.
Oil grade:API grade SL “Energy −Conserving” or
ILSAC multigrade engine oil
Recommended viscosity: SAE 5W −30
Outside temperature
SAE 5W30 is the best choice for good
fuel economy and good starting in cold
weather. If SAE 5W30 is not available, SAE
10W30 may be used. However, it
should be replaced with SAE 5W30 at
the next oil change.
API service symbol
ILSAC certification mark

04 SIENNA_U (L/O 0408)
458
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Oil identification marks
Either or both API registered marks are
added to some oil containers to help
you select the oil you should use.
The API Service Symbol is located any-
where on the outside of the container.
The top portion of the label shows the oil
quality by API (American Petroleum Insti-
tute) designations such as SL. The center
portion of the label shows the SAE viscos-
ity grade such as SAE 5W−30. “Energy −
Conserving” shown in the lower portion,
indicates that the oil has fuel −saving ca-
pabilities.
The ILSAC (International Lubricant Stan-
dardization and Approval Committee) Certi-
fication Mark is displayed on the front of
the container.
To ensure excellent lubrication perfor-
mance for your engine, “Toyota Genuine
Motor Oil” is available, which has been
specifically tested and approved for all
Toyota engines.
Please contact your Toyota dealer for fur-
ther details about “Toyota Genuine Motor
Oil”. Look at the seethrough coolant reser-
voir when the engine is cold. The cool-
ant level is satisfactory if it is between
the “FULL” and “LOW” lines on the
reservoir. If the level is low, add ethyl-
eneglycol type coolant for a proper
corrosion protection of aluminum com-
ponents.
The coolant level in the reservoir will vary
with engine temperature. However, if the
level is on or below the “LOW” line, add
coolant. Bring the level up to the “FULL”
line.
Always use ethylene
−glycol type coolant
for a proper corrosion protection of alumi-
num components. See information in the
next column.
If the coolant level drops within a short
time after replenishing, there may be a
leak in the system. Visually check the
radiator, hoses, engine coolant filler cap,
radiator cap and drain cock and water
pump.
If you can find no leak, have your Toyota
dealer test the cap pressure and check
for leaks in the cooling system.
Checking the engine coolant
level