2003 TOYOTA SIENNA tow

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Total trailer weight Tongue loadTongue load
Total trailer weight 
100 = 9 to 11%
(∗
1)
or 15% (∗
2)
The trailer cargo load should be
distributed so that the tongue load
is 9 to 11% for weight carrying
hitch
(∗
1) or 15% for weight distrib-
ut i ng hi t ch ( ∗
2) of the total trailer
weight, not exceeding the maximum
load of the following.
Weight carrying hitch
Without towing package 90 kg (200 lb.)
With towing package
158 kg (350 lb.)
Weight distributing hitch With towing package
238 kg (525 lb.)
Never load the trailer with more
weight in the back than in the
front. About 60% of the trailer load
should be in the front half of the
trailer and the remaining 40% in the
rear.
HITCHES
If you wish to install a trailer hitch, you
should consult with your Toyota dealer.
Use only a hitch recommended by the
hitch manufacturer and the one which
conforms to the total trailer weight
requirement.
The hitch must be bolted securely to
the vehicle frame and installed accord-
ing to the hitch manufacturer ’s instruc-
tions.
The hitch ball and king pin should have
a light coat of grease.
Toyota recommends removing the trail-
er hitch whenever you are not towing
a trailer to reduce the possib ility of
additional damage caused by the hitch
if your vehicle is struck from behind.
After removing the hitch, seal any
mounting holes in the vehicle body to
prevent entry of pollutants such as ex-
haust fumes, dirt, water, etc.
NOTICE
Do not use axlemounted hitches as
they can cause damage to the axle
housing, wheel bearings, wheels or
tires. Also, never install a hitch which
may interfere with the normal function
of an Energy Absorbing Bumper, if so
equipped.
BRAKES AND SAFETY CHAINS
Toyota recommends trailers with
brakes that conform to any applica-
ble federal and state/provincial regu-
lations.

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A safety chain must always be used
between the towing vehicle and the
trailer. Leave sufficient slack in the
chain for turns. The chain should
cross under the trailer tongue to
prevent the tongue from dropping to
the ground in case it becomes dam-
aged or separated. For correct safety
chain procedures, follow the hitch or
trailer manufacturer ’s recommenda-
tions.
CAUTION
If the total trailer weight exceeds
453 kg (1000 lb.), trailer brakes are
required.
Never tap into your vehicle’s hy-
draulic system as it would lower its
braking effectiveness.
Never tow a trailer without using a
safety chain securely attached to
both the trailer and the vehicle. If
damage occurs to the coupling unit
or hitch ball, there is danger of the
trailer wandering over into another
lane.
TIRES
Ensure that your vehicle’s tires are
properly inflated. Adjust the tire pres-
sure to the recommended cold tire
pressure indicated below. (See Section
72 and Section 8 for instructions.):
Tire pressure, kPa (kgf/cm
2 or bar, psi)
240 (2.4, 35)
The trailer tires should be inflated to
the pressure recommended by the trail-
er manufacturer in respect to the total
trailer weight.
TRAILER LIGHTS
Trailer lights must comply with federal,
state/provincial and local regulations.
See your local recreational vehicle
dealer or rental agency for the correct
type of wiring and relays for your trail-
er. Check for correct operation of the
turn signals and stop lights each time
you hitch up. Direct splicing may dam-
age your vehicle’s electrical system
and cause a malfunction of your lights. BREAKIN SCHEDULE
Toyota recommends that you do not
tow a trailer with a new vehicle or a
vehicle with any new power train com-
ponent (engine, transmission, differen-
tial, wheel bearing, etc.) for the first
800 km (500 miles) of driving.
MAINTENANCE
If you tow a trailer, your vehicle will
require more frequent maintenance due
to the additional load. For this
information, please refer to the
scheduled maintenance information in
the “Scheduled Maintenance Guide” or
“Owner ’s Manual Supplement”.
Retighten all fixing bolts of the towing
ball and bracket after approximately
1000 km (600 miles) of trailer driving.
PRETOWING SAFETY CHECK
Check that your vehicle remains level
when a loaded or unloaded trailer is
hitched. Do not drive if the vehicle has
an abnormal noseup or nosedown
condition, and check for improper
tongue load, overload, worn suspension
or other possible causes.
Make sure the trailer cargo is securely
loaded so that it cannot shift.

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Check that your rear view mirrors con-
form to any applicable federal, state/
provincial or local regulations. If not,
install the rear view mirrors required
for towing purpose.
TRAILER TOWING TIPS
When towing a trailer, your vehicle will
handle differently than when not tow-
ing. The three main causes of vehicle
trailer accidents are driver error, exces-
sive speed and improper trailer loading.
Keep these in mind when towing:
Before starting out, check operation of
the lights and all vehicletrailer connec-
tions. After driving a short distance,
stop and recheck the lights and con-
nections. Before actually towing a trail-
er, practice turning, stopping and back-
ing with a trailer in an area away from
traffic until you learn the feel.
Backing with a trailer is difficult and
requires practice. Grip the bottom of
the steering wheel and move your hand
to the left to move the trailer to the
left. Move your hand to the right to
move the trailer to the right. (This pro-
cedure is generally opposite to that
when backing without a trailer.) Also,
just turn the steering wheel a little at
a time, avoiding sharp or prolonged
turning. Have someone guide you when
backing to reduce the risk of an acci-
dent.
Because stopping distance may be in-
creased, vehicletovehicle distance
should be increased when towing a
trailer. For each 16 km/h (10 mph) of
speed, allow at least one vehicle and
trailer length between you and the ve-
hicle ahead. Avoid sudden braking as
you may skid, resulting in jackknifing
and loss of control. This is especially
true on wet or slippery surfaces.
Avoid jerky starts or sudden accelera-
tion.
Avoid jerky steering and sharp turns.
The trailer could hit your vehicle in a
tight turn. Slow down before making a
turn to avoid the necessity of sudden
braking.
Remember that when making a turn,
the trailer wheels will be closer than
the vehicle wheels to the inside of the
turn. Therefore, compensate for this by
making a larger than normal turning
radius with your vehicle.
Crosswinds and rough roads will ad-
versely affect handling of your vehicle
and trailer, causing sway. Pay attention
to the rear from time to time to pre-
pare yourself for being passed by large
trucks or buses, which may cause your
vehicle and trailer to sway. If swaying
happens, firmly grip the steering wheel
and reduce speed immediately but
gradually. Never increase speed. Steer
straight ahead. If you make no extreme
correction with the steering or brakes,
the vehicle and trailer will stabilize.
Be careful when passing other ve-
hicles. Passing requires considerable
distance. After passing a vehicle, do
not forget the length of your trailer and
be sure you have plenty of room be-
fore changing lanes.
In order to maintain engine braking effi-
ciency, do not use overdrive.

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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” 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” position, start the engine. Be sure to keep the
brake pedal depressed.
2. Shift into gear.
3. Release the parking brake and brake pedal and slowly pull or back away
from the wheel blocks. 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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IN CASE OF AN EMERGENCY
If your vehicle will not start254
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If your engine stalls while driving 257
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If your vehicle overheats 257
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If you have a flat tire 258
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. . . . .
If your vehicle becomes stuck 268
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If your vehicle needs to be towed 269
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If you lose your keys 271
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. . . .
If you lose your wireless remote control transmitter 271
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SECTION 4

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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.
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
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.
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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Steel wheels
Aluminum wheels
10. Reinstall the wheel ornament.1. Put the wheel ornament into position.
Steel wheel models, align the cutout of
the wheel ornament with the valve stem
as shown. 2. Then tap it firmly with the side or heel of your hand to snap it into place.
CAUTION
Take due care in handling the orna-
ment to avoid unexpected personal
injury.
11. Check the air pressure of the re- placed tire.
Adjust the air pressure to the specification
designed in Section 8. If the pressure is
lower, drive slowly to the nearest service
station and fill to the correct pressure.
Do not forget to reinstall the tire inflation
valve cap as dirt and moisture could get
into the valve core and possibly cause air
leakage. If the cap is missing, have a new
one put on as soon as possible.
12. Restow all the tools, jack and flat tire securely.
As soon after changing wheels as pos-
sible, tighten the wheel nuts to the torque
specified in Section 8 with a torque
wrench. Have a technician repair the flat
tire.
Vehicles with a spare tire of the same
size as the installed tires—
13. Push the tire pressure warning sys- tem reset switch.
Initial adjustment of the tire pressure
warning system is necessary after you
have replaced your tires or wheels. See
“Tire pressure warning system” in Section
16.
—Reinstalling wheel ornament —After changing wheels

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CAUTION
Before driving, make sure all the
tools, jack and flat tire are securely
in place in their storage location to
reduce the possibility of personal in-
jury during a collision or sudden
braking.
If your vehicle becomes stuck in snow,
mud, sand, etc., then you may attempt
to rock the vehicle free by moving it
forward and backward.
If your vehicle is equipped with the
traction control system, turn off the
system to become unstuck. (For details,
see “Traction control system” in Sec-
tion 16.)
CAUTION
Do not attempt to rock the vehicle
free by moving it forward and back-
ward if people or objects are any-
where near the vehicle. During the
rocking operation the vehicle may
suddenly move forward or backward
as it becomes unstuck, causing injury
or damage to nearby people or ob-
jects.
NOTICE
If you rock your vehicle, observe the
following precautions to prevent dam-
age to the transmission and other
parts.
 Do not depress the accelerator ped-
al while shifting the selector lever
or before the transmission is com-
pletely shifted to forward or reverse
gear.
 Do not race the engine and avoid
spinning the wheels.
 If your vehicle remains stuck after
rocking the vehicle several times,
consider other ways such as tow-
ing.
If your vehicle becomes stuck