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385
2-5. Driving information
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When driving
SIENNA_OM_OM45483U_(U)
●
Take care when passing other vehicles. Passing requires consider-
able distance. After passing a vehicle, do not forget the length of
your trailer, and be sure you hav e plenty of room before changing
lanes.
● To maintain engine braking efficiency and charging system perfor-
mance when using engine braking, do not put the transmission in
D. If in the S mode, transmission shift range position must be in 4
or lower.
● Instability happens more frequently when descending steep or long
downhill grades. Before descending, slow down and downshift. Do
not make sudden downshifts while descending steep or long down-
hill grades.
● Avoid holding the brake pedal down too long or applying the
brakes too frequently. This could cause the brakes to overheat and
result in reduced braking efficiency.
● Due to the added load of the trailer, your vehicle’s engine may
overheat on hot days (at temper atures over 85°F [30°C]) when
driving up a long or steep grade. If the Engine coolant temperature
gauge overheating, immediately turn off the air conditioning (if in
use), pull your vehicle off the road and stop in a safe spot.
( P. 790)
Page 386 of 872
386 2-5. Driving information
SIENNA_OM_OM45483U_(U)●
Always place wheel blocks under both the vehicle’s and the
trailer’s wheels when parking. Ap ply the parking brake firmly, and
put the transmission in P. Avoid parking on a slope, but if unavoid-
able, do so only after performing the following:
Apply the brakes and keep them applied.
Have someone place wheel blo cks under both the vehicle’s
and trailer’s wheels.
When the wheel blocks are in place, release the brakes slowly
until the blocks absorb the load.
Apply the parking brake firmly.
Shift into P and turn off the engine.
● When restarting after parking on a slope:
With the transmission in P, start the engine. Be sure to keep
the brake pedal pressed.
Shift into a forward gear. If reversing, shift into R.
Release the parking brake and brake pedal, and slowly pull or
back away from the wheel blocks. Stop and apply the brakes.
Have someone retrieve the blocks.
STEP1
STEP2
STEP3
STEP4
STEP5
STEP1
STEP2
STEP3
STEP4
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387
2-5. Driving information
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When driving
SIENNA_OM_OM45483U_(U)
■
Matching trailer ball height to trailer coupler height
■ Before towing
Check that the following conditions are met:
●Ensure that your vehicle’s tires are properly inflated. ( P. 807)
● Trailer tires are inflated according to the trailer manufacturer’s recom-
mendation.
● All trailer lights work as required by law.
● All lights work each time you connect them.
● The trailer ball is set at the proper height for the coupler on the trai\
ler.
● The trailer is level when it is hitched.
Do not drive if the trailer is not level, and check for improper tongue
weight, overloading, worn suspension, or other possible causes.
● The trailer cargo is securely loaded.
● The rear view mirrors conform to all applicable federal, state/provincial or
local regulations. If they do not, instal l rear view mirrors appropriate for
towing purposes.
No matter which class of tow hitch
applies, for a safe trailer hookup, the
trailer ball setup on must be proper height
for the coupler on the trailer.
Coupler
Trailer ball
Page 388 of 872
388 2-5. Driving information
SIENNA_OM_OM45483U_(U)
■Break-in schedule
If your vehicle is new or equipped with any new power train components
(such as an engine, transmission, differential or wheel bearing), Toyota rec-
ommends that you do not tow a trailer until the vehicle has been driven \
for
over 500 miles (800 km).
After the vehicle has been driven for over 500 miles (800 km), you can s\
tart
towing. However, for the next 500 miles (800 km), drive the vehicle at a
speed of less than 50 mph (80 km/h) when towing a trailer, and avoid full
throttle acceleration.
■ Maintenance
●If you tow a trailer, your vehicle will require more frequent maintenance
due to the additional load. (See “Scheduled Maintenance Guide” or
“Owner’s Manual Supplement”.)
● Retighten the fixing bolts of the towing ball and bracket after approxi-
mately 600 miles (1000 km) of trailer towing.
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2-5. Driving information
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When driving
SIENNA_OM_OM45483U_(U)
■
If trailer sway occurs
One or more factors (crosswinds, passing vehicles, rough roads, etc.) can
adversely affect handling of your vehicle and trailer, causing instability.
●If trailer swaying occurs:
• Firmly grip the steering wheel. Steer straight ahead.
Do not try to control trailer swaying by turning the steering wheel.
• Begin releasing the accelerator pedal immediately but very gradually to reduce speed.
Do not increase speed. Do not apply vehicle brakes.
If you make no extreme correction with the steering or brakes, your vehicle
and trailer should stabilize.
● After the trailer swaying has stopped:
• Stop in a safe place. Get all occupants out of the vehicle.
• Check the tires of the vehicle and the trailer.
• Check the load in the trailer.
Make sure the load has not shifted.
Make sure the tongue weight is appropriate, if possible.
• Check the load in the vehicle. Make sure the vehicle is not overloaded after occupants get in.
If you cannot find any problems, the speed at which trailer swaying occu\
rred
is beyond the limit of your particular vehicle-trailer combination.
Drive at a lower speed to prevent instability. Remember that swaying of the
towing vehicle-trailer increases as speed increases.
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390 2-5. Driving information
SIENNA_OM_OM45483U_(U)
CAUTION
■Trailer towing precautions
To tow a trailer safely, use extreme care and drive the vehicle in accordance
with the trailer’s characteristics and operating conditions. Failure to do so
could cause an accident resulting in death or serious injury. Vehicle stability
and braking performance are affected by trailer stability, brake setting and
performance, and the hitch. Your vehicle will handle differently when towing
a trailer.
■ To avoid accident or injury
●Do not exceed the TWR, unbraked TWR, GCWR, GVWR or GAWR.
● If the gross trailer weight is over 2000 lb. (907 kg), a sway control device
with sufficient capacity is required.
● Adjust the tongue weight within the appropriate range. Place heavier loads
as close to the trailer axle as possible.
● Do not exceed 65 mph (104 km/h), the posted towing speed limit or the
speed limit for your trailer as set forth in your trailer owner’s manual,
whichever is lowest. Slow down sufficiently before making a turn, in cross-
winds, on wet or slippery surface, etc. to help avoid an accident. If you
experience a vehicle-trailer instability from reducing a certain speed, slow
down and make sure you keep your vehicle speed under the speed of
which you experience the instability.
● Do not make jerky, abrupt or sharp turns.
● Do not apply the brakes suddenly as you may skid, resulting in jackknifing
and loss of vehicle control. This is especially true on wet or slippery sur-
faces.
● Do not exceed the trailer hitch assembly weight, gross vehicle weight,
gross axle weight and trailer tongue weight capacities.
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391
2-5. Driving information
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When driving
SIENNA_OM_OM45483U_(U)
CAUTION
■
To avoid accident or injury
●Do not use cruise control when towing.
● Slow down and downshift before descending steep or long downhill
grades. Do not make sudden downshifts while descending steep or long
downhill grades.
● Vehicle-trailer instability is more likely on steep long downhills. Before
descending steep or long downhill grades, slow down and downshift. Do
not make sudden downshifts when descending steep or long downhill
grades. Avoid holding the brake pedal down too long or applying the
brakes too frequently. This could cause the brakes to overheat and result
in reduced braking efficiency.
● Vehicles with compact spare tire: Do not tow a trailer when the compact
spare tire is installed on your vehicle.
■ Hitch
Trailer hitch assemblies have different weight capacities established by the
hitch manufacturer. Even though the vehicle may be physically capable of
towing a higher weight, the operator must determine the maximum weight
rating of the particular hitch assembly and never exceed the maximum
weight rating specified for the trailer-hitch. Exceeding the maximum weight
rating set by the trailer-hitch manufacturer can cause an accident resulting in
death or serious personal injuries.
Page 392 of 872

392 2-5. Driving information
SIENNA_OM_OM45483U_(U)
CAUTION
■When towing a trailer
Toyota recommends trailers with brakes that conform to any applicable fed-
eral and state/provincial regulations.
●If the gross trailer weight exceeds unbraked TWR, trailer brakes are
required. Toyota recommends trailers with brakes that conform to all appli-
cable federal and state/provincial regulations.
● Never tap into your vehicle’s hydraulic system, as this will lower the vehi-
cle’s 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 into another lane.
NOTICE
■When installing a trailer hitch
Use only the position recommended by your Toyota dealer. Do not install the
trailer hitch on the bumper; this may cause body damage.
■ Do not directly splice trailer lights
Do not directly splice trailer lights. Directly splicing trailer lights may damage
your vehicle’s electrical system and cause a malfunction.