2008 TOYOTA SIENNA engine

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Because of the added load of the trail-
er, your vehicle’s engine may overheat
on hot days (at temperatures over
30C [85 F]) when going up a long or
steep grade with a trailer. If the engine
coolant temperature gauge indicates
overheating, immediately turn off the air
conditioning (if in use), pull off the road
and stop in a safe spot. Refer to “If
your vehicle overheats” on page 470 in
Section 4.
Always place wheel blocks under both
the vehicle and trailer wheels when
parking. Apply the parking brake firmly.
Put the transmission in “P”. Avoid park-
ing on a slope with a trailer, but if it
cannot be avoided, do so only after
performing the following:
1. Apply the brakes and hold.
2. Have someone place wheel blocks un- der both the vehicle and trailer wheels.
3. When the wheel blocks are in place, release your brakes slowly until the
blocks absorb the load.
4. Apply the parking brake firmly.
5. Shift into “P” and turn off the engine. When restarting out after parking on a
slope:
1. With the transmission in “P”, start the engine. Be sure to keep the brake ped-
al depressed.
2. Shift into gear.
3. Release the parking brake and brake pedal and slowly pull or back away
from the wheel blo cks. Stop and apply
your brakes.
4. Have someone retrieve the blo cks.
CAUTION
Do not exceed 72 km/h (45 mph) or
the posted towing speed limit,
whichever is lower. Because insta-
bility (swaying) of a towing vehicle
trailer combination usually in-
creases as the speed increases, ex-
ceeding 72 km/h (45 mph) may
cause loss of control.
Slow down and downshift before
descending steep or long downhill
grades. Do not make sudden down-
shifts.
Avoid holding the brake pedal down
too long or too frequently. This
could cause the brakes to overheat
and result in reduced braking effi-
ciency.

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Improving fuel economy is easy—just take
it easy. It will help make your vehicle last
longer, too. Here are some specific tips
on how to save money on both fuel and
repairs:
Keep your tires inflated at the cor-
rect pressure. Underinflation causes
tire wear and wastes fuel. See page
523 in Section 7 −2 for instructions.
Do not carry unneeded weight in
your vehicle. Excess weight puts a
heavier load on the engine, causing
greater fuel consumption.
Avoid lengthy warmup idling. Once
the engine is running smoothly, begin
driving—but gently. Remember, howev-
er, that on cold winter days this may
take a little longer.
Put the selector lever into the “D”
when engine braking is not required.
Driving with the selector lever in “4”
will reduce the fuel economy. (For de-
tails, see “Automatic transmission” on
page 205 in Section 1 −7.)
Accelerate slowly and smoothly.
Avoid jackrabbit starts. Get into high
gear as quickly as possible.
Avoid long engine idling. If you have
a long wait and you are not in traffic,
it is better to turn off the engine and
start again later.
Avoid engine lugging or overrev-
ving. Use a gear position suitable for
the road on which you are travelling.
Avoid continuous speeding up and
slowing down. Stop−and− go driving
wastes fuel.
Avoid unnecessary stopping and
braking. Maintain a steady pace. Try
to time the traffic signals so you only
need to stop as little as possible or
take advantage of through streets to
avoid traffic lights. Keep a proper dis-
tance from other vehicles to avoid sud-
den braking. This will also reduce wear
on your brakes.
Avoid heavy traffic or traffic jams
whenever possible.
Do not rest your foot on the brake
pedal. This causes premature wear,
overheating and poor fuel economy.
Maintain a moderate speed on high-
ways. The faster you drive, the greater
the fuel consumption. By reducing your
speed, you will cut down on fuel con-
sumption.
Keep the front wheels in proper
alignment. Avoid hitting the curb and
slow down on rough roads. Improper
alignment not only causes faster tire
wear but also puts an extra load on
the engine, which, in turn, wastes fuel.
Keep the bottom of your vehicle free
from mud, etc. This not only lessens
weight but also helps prevent corro-
sion.
Keep your vehicle tunedup and in
top shape. A dirty air cleaner, improp-
er valve clearance, dirty plugs, dirty oil
and grease, brakes not adjusted, etc.
all lower engine performance and con-
tribute to poor fuel economy. For longer
life of all parts and lower operating
costs, keep all maintenance work on
schedule, and if you often drive under
severe conditions, see that your vehicle
receives more frequent maintenance.
(For scheduled maintenance informa-
tion, please refer to the “Scheduled
Maintenance Guide” or “Owner ’s Manu-
al Supplement”.)
How to save fuel and make
your vehicle last longer

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CAUTION
Never turn off the engine to coast
down hills. Your power steering and
brake booster will not function with-
out the engine running. Also, the
emission control system operates
properly only when the engine is run-
ning.

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IN CASE OF AN EMERGENCY
In case of an emergency
If your vehicle will not start466
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If your engine stalls while driving 469
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If you cannot increase engine speed 469
. . . . . . . . . . . . . . . . . . . . . . . . . .
If your vehicle overheats 470
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
If you have a flat tire 471
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . .
If your vehicle becomes stuck 490
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If your vehicle needs to be towed 490
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If you lose your keys 492
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . .
If you lose your wireless remote control transmitter 493
. . . . . . . . . . . . .
If you cannot shift automatic transmission selector lever 493
. . . . . . . .
If you cannot operate back door opener 494
. . . . . . . . . . . . . . . . . . . . . . .
SECTION 4

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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 452 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
467 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 engine switch 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 466 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 engine switch to
“START” with the accelerator pedal fully
depressed. Keep the engine switch and
accelerator pedal in these positions for 15
seconds and release them. Then try start-
ing the engine with your foot off the accel-
erator pedal.
If the engine does not start after 15 se-
conds of cranking, release the engine
switch, 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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To avoid serious personal injury and
damage to your vehicle which might re-
sult from battery explosion, acid burns,
electrical burns, or damaged electronic
components, these instructions must be
followed precisely.
If you are unsure about how to follow this
procedure, we strongly recommend that
you seek the help of a competent me-
chanic or towing service.
CAUTION
Batteries contain sulfuric acid
which is poisonous and corrosive.
Wear protective safety glasses when
jump starting, and avoid spilling
acid on your skin, clothing, or ve-
hicle.
If you should accidentally get acid
on yourself or in your eyes, remove
any contaminated clothing and flush
the affected area with water imme-
diately. Then get immediate medical
attention. If possible, continue to
apply water with a sponge or cloth
while en route to the medical office.
The gas normally produced by a
battery will explode if a flame or
spark is brought near. Use only
standardized jumper cables and do
not smoke or light a match while
jump starting.
NOTICE
The battery used for boosting must
be 12 V. Do not jump start unless you
are sure that the booster battery is
correct.
JUMP STARTING PROCEDURE1. If the booster battery is installed in another vehicle, make sure the vehicles
are not touching. Turn off all unneces-
sary lights and accessories.
When boosting, use the battery of
matching or higher quality. Any other
battery may be difficult to jump start
with.
If jump starting is difficult, charge the
battery for several minutes.
2. If required, remove all the vent plugs from the booster and discharged batter-
ies. Lay a cloth over the open vents
on the batteries. (This helps reduce the
explosion hazard, personal injuries and
burns.)
3. If the engine in the vehicle with the booster battery is not running, start it
and let it run for a few minutes. During
jump starting, run the engine at about
2000 rpm with the accelerator pedal
lightly depressed.
(c) Jump starting

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Discharged batteryBooster battery
Positive terminal
(“+” mark)
Jumper cable
Positive
terminal
(“+” mark)
4. Make the cable connections in the or-
der a, b, c, d.
a. Connect the clamp of the positive
(red) jumper cable to the positive (+)
terminal on the discharged battery.
b. Connect the clamp at the other end
of the positive (red) jumper cable to
the positive (+) terminal on the booster
battery.
Jumper cable
Booster
battery
Negative terminal
(“− ” mark)
Discharged battery
c. Connect the clamp of the negative
(black) jumper cable to the negative (
−)
terminal on the booster battery.
d. Connect the clamp at the other end
of the negative (black) jumper cable to
a solid, stationary, unpainted, metallic
point of the vehicle with the discharged
battery.
The recommended connecting point is
shown in the following illustration:Connecting point
Do not connect the cable to or near
any part that moves when the engine
is cranked.
CAUTION
When making the connections, to
avoid serious injury, do not lean over
the battery or accidentally let the
jumper cables or clamps touch any-
thing except the correct battery termi-
nals or the ground.

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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 engine switch 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 466 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 engine switch 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