2007 TOYOTA SIENNA wiring

07 SIENNA_U (L/O 0612)
11 9
2007 SIENNA from Oct. ’06 Prod. (OM45437U)
The seat belt pretensioners are controlled
by the airbag sensor assembly. The airbag
sensor assembly consists of a safing sen-
sor and airbag sensor.
When the seat belt pretensioners are acti-
vated, an operating noise may be heard
and a small amount of non−toxic gas may
be released. This does not indicate that
a fire is occurring. This gas is normally
harmless.
Once the seat belt pretensioners have
been activated, the seat belt retractors
remain locked.
CAUTION
Do not modify, remove, strike or open
the seat belt pretensioner assemblies,
airbag sensor or surrounding area or
wiring. Failure to follow these instruc-
tions may prevent the seat belt pre-
tensioners from activating correctly,
cause sudden operation of the system
or disable the system, which could
result in death or serious injury. Con-
sult your Toyota dealer about any re-
pair and modification.
NOTICE
Do not perform any of the following
changes without consulting your
Toyota dealer. Such changes can
interfere with proper operation of the
seat belt pretensioners in some
cases.
 Installation of electronic devices
such as a mobile twoway radio,
cassette tape player or compact
disc player
 Repairs on or near the front seat
belt pretensioner assemblies
 Modification of the suspension sys-
tem
 Modification of the front end struc-
ture
 Attachment of a grille guard (bull
bar, kangaroo bar, etc.), snowplow,
winches or any other equipment to
the front end
 Repairs made on or near the front
fenders, front end structure or con-
sole
This indicator comes on when the igni-
tion switch is turned to the “ON” posi-
tion. It goes off after about 6 seconds.
This means the seat belt pretensioners
are operating properly.

07 SIENNA_U (L/O 0612)
425
2007 SIENNA from Oct. ’06 Prod. (OM45437U)
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. See page 487 in Sec-
tion 7−2 and page 517 in Section 8 for
instructions.
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 nose −up or nose −down
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.
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.

07 SIENNA_U (L/O 0612)
432
2007 SIENNA from Oct. ’06 Prod. (OM45437U)
Before making these checks, make sure
you have followed the correct starting pro-
cedure given in “How to start the engine”
on page 418 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
433 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 ignition key 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 432 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 key to “START”
with the accelerator pedal fully depressed.
Keep the key and accelerator pedal in
these positions for 15 seconds and re-
lease them. Then try starting the engine
with your foot off the accelerator pedal.
If the engine does not start after 15 se-
conds of cranking, release the key, 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