2004 TOYOTA SIENNA check engine

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)
451
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Be extremely cautious when work-
ing on the battery. It contains poi-
sonous and corrosive sulfuric acid.
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.
 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
Rear (twowheel drive models)
Positioning the jack

04 SIENNA_U (L/O 0408)
453
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Here is a list of parts and tools you will
need to perform do−it−yourself 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 page 456 in Section 7 −2 for de-
tails about engine 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 page 458 in Section 7 −2 for de-
tails about coolant type selection.
Demineralized or distilled water
Tools:
Funnel (only for adding coolant) CHECKING BRAKE FLUID
Parts (if level is low):
SAE J1703 or FMVSS No.116 DOT 3
brake fluid
Tools:
Rag or paper towel
Funnel (only for adding fluid)
CHECKING POWER STEERING FLUID
Parts (if level is low):
Automatic transmission fluid
DEXRON®II or III
Tools:
Rag or paper towel
Funnel (only for adding fluid)
CHECKING BATTERY CONDITION
Tools:
Warm water
Baking soda
Grease
Conventional wrench (for terminal
clamp bolts) CHECKING AND REPLACING FUSES
Parts (if replacement is necessary):
Genuine Toyota fuse or equivalent with
same amperage rating as original
ADDING WASHER FLUID
Parts:
Water
Washer fluid containing antifreeze (for
winter use)
Tools:
Funnel
REPLACING LIGHT BULBS
Parts:
Bulb with same number and wattage
rating as original (See charts in
“Replacing light bulbs” on page 480 in
Section 7 −3.)
Tools:
Screwdriver
Wrench
Parts and tools

04 SIENNA_U (L/O 0408)
455
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
DOITYOURSELF MAINTENANCE
Engine and Chassis
Checking the engine oil level456
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine coolant level 458
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the radiator and condenser 460
. . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing the air conditioning filter 460
. . . . . . . . . . . . . . .
Checking brake fluid 462
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . .
Checking power steering fluid 463
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking tire inflation pressure 463
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing tires 466
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rotating tires 468
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . . .
Run −flat tires 469
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . . .
Installing snow tires and chains 471
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing wheels 473
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . .
Aluminum wheel precautions 474
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 7 2

04 SIENNA_U (L/O 0408)
456
2004 SIENNA from Aug. ’04 Prod. (OM45422U)
Low level Full level
Add oil O.K. Too full
With the engine at operating tempera-
ture and turned off, check the oil level
on the dipstick. 1. To get a correct reading, the vehicle should be on level ground. After turning
off the engine, wait a few minutes for
the oil to drain back into the bottom of
the engine.
2. Pull the dipstick out, hold a rag under the end and wipe it clean.
3. Reinsert the dipstick—push it in as far as it will go, or the reading will not be
correct.
4. Pull the dipstick out and look at the oil level while holding a rag under the
end.
CAUTION
Be careful not to touch the hot ex-
haust manifold.
NOTICE
Be careful not to drop engine oil on
the vehicle components.
If the oil level is below or only slightly
above the low level, add engine oil of
the same type as already in the engine.
Remove the oil filler cap and add engine
oil in small quantities at a time, checking
the dipstick. We recommend that you use
a funnel when adding oil.
The approximate quantity of oil needed to
raise the level between low and full on the
dipstick is indicated below for reference.
When the level reaches within the correct
range, install the filler cap hand− tight.
Oil quantity, L (qt., Imp. qt.): 1.5 (1.6, 1.3)
NOTICE
 Be careful not to spill engine oil on
the vehicle components.
 Avoid overfilling, or the engine
could be damaged.
 Check the oil level on the dipstick
once again after adding the oil.
Checking the engine oil level

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