1999 TOYOTA SIENNA engine

name. SIENNA (45403U)
202
Check that your rear view mirrors con-
form to any applicable federal, state/
provincial or local regulation. 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 vehicle−trailer 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, vehicle−to−vehicle 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.
ProCarManuals.com

name. SIENNA (45403U)
203 
Because of the added load of the trail-
er, your vehicle’s engine may overheat
on hot days (at temperatures over
30C [85F]) 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 Part 4 of
this manual.
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 blocks.
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.
ProCarManuals.com

name. SIENNA (45403U)
204
Getting more kilometers/mileage from a
liter/gallon of fuel 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 Chapter
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 warm−up 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.
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 lug or overrevving. 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 needless 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 tuned−up 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 contrib-
ute 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 separate
”Scheduled Maintenance Guide” or
”Owner ’s Manual Supplement”).
How to save fuel and make
your vehicle last longer, too
ProCarManuals.com

name. SIENNA (45403U)
205
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.
ProCarManuals.com

name. SIENNA (45403U)
207
Part 4
IN CASE OF AN
EMERGENCY
If your vehicle will not start
If your engine stalls while
driving
If your vehicle overheats
If you have a flat tire
If your vehicle needs to be
towed
If you lose your keys
If you lose your wireless remote
control transmitter
Before making these checks, make sure
you have followed the correct starting pro-
cedure given in ”How to start the engine”
in Part 3 and that you have sufficient fuel.
If your vehicle is equipped with the engine
immobiliser system, 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, the system is
possibly broken. Call your Toyota dealer.
(See ”Keys (with engine immobiliser sys-
tem)” in Chapter 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” 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 push−start the ve-
hicle. It may damage the vehicle or
cause a collision when the engine
starts. Also the three−way catalytic
converter may overheat and become a
fire hazard.
If the engine turns over at its normal
speed but will not start—
1. Check that all the push−on connectors
are tight. (For example, connectors at
the spark plugs, ignition coil and/or dis-
tributor)
2. If the connectors are O.K., the engine
may be flooded because of repeated
cranking. See ”(b) Starting a flooded
engine” for further instructions.
If your vehicle will not start—
(a) Simple checks
ProCarManuals.com

name. SIENNA (45403U)
208
(b) Starting a flooded engine
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 held down.
Keep the key and accelerator pedal so for
15 seconds and release 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.
(c) Jump starting
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.
ProCarManuals.com

name. SIENNA (45403U)
209
JUMP STARTING PROCEDURE
1. 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.Discharged
battery
Booster
battery
Positive
terminal
(”+” mark)
Positive terminal
(”+” mark) Jumper
cable
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
Discharged
batteryBooster
battery
Negative
terminal (”–” mark)
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:
ProCarManuals.com

name. SIENNA (45403U)
210
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.
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.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. Try starting the engine again.
If the engine will not start, see ”If your
vehicle will not start”.
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 your engine stalls while
driving
ProCarManuals.com