2004 TOYOTA SIENNA check engine

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“VSC” warning light
This light warns that there is a problem
somewhere in the traction control system
or the vehicle stability control system.
The light will come on when the ignition
key is turned to “ON” and will go off after
a few seconds.
If the light comes on while driving, the
system does not work. However, as con-
ventional braking operates when applied,
there is no problem to continue your driv-
ing.In the following cases, contact your Toyota
dealer:
The warning light does not come on
after the ignition key is turned to “ON”.
The warning light remains on after the
ignition key is turned to “ON”.
The warning light comes on while driv-
ing.
The vehicle stability control system
helps provide integrated control of the
systems such as an antilock brake
system, brake assist system, traction
control, engine control, etc. This sys-
tem automatically controls the brakes
and engine to help prevent the vehicle
from skidding when cornering on a slip-
pery road surface or operating steering
wheel abruptly.
This system activates when the vehicle
speed is about more than 15 km/h (9
mph).
You may hear a sound in the engine
compartment for a few seconds just after
the vehicle begins to move. This means
that the system is in the self
−check mode,
but does not indicate a malfunction.
Vehicle stability control
system

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If you need acceleration—for example,
when passing—depress the accelerator
pedal enough for the vehicle to exceed
the set speed. When you release it, the
vehicle will return to the speed set prior
to the acceleration.
CANCELLING THE PRESET SPEED
You can cancel the preset speed by:
a. Pulling the lever in the “CANCEL” di-rection and releasing it.
b.
Depressing the brake pedal.
If the vehicle speed falls below about 40
km/h (25 mph), the preset speed will auto-
matically cancel out.
If the vehicle speed drops 16 km/h (10
mph) below the preset speed, the preset
speed will also automatically cancel out.
If the preset speed automatically cancels
out other than for the above cases, have
your vehicle checked by your Toyota deal-
er at the earliest opportunity. RESETTING TO A FASTER SPEED
Push the lever up in the “+ RES” direction
and hold it. Release the lever when the
desired speed is attained. While the lever
is held up, the vehicle will gradually gain
speed.
However, a faster way to reset is to ac-
celerate the vehicle and then push the
lever down in the “− SET” direction.
RESETTING TO A SLOWER SPEED
Push the lever down in the “
− SET” direc-
tion and hold it. Release the lever when
the desired speed is attained. While the
lever is held down, the vehicle speed will
gradually decrease.
However, a faster way to reset is to de-
press the brake pedal and then push the
lever down in the “− SET” direction.
Even if you downshift from “D” to “4”, with
the cruise control on, engine braking will
not be enabled because the cruise control
is not cancelled. To decrease the vehicle
speed, reset to a slower speed with the
cruise control lever or depress the brake
pedal. If you use the brake pedal, cruise
control is cancelled. RESUMING THE PRESET SPEED
If the preset speed is cancelled by pulling
the control lever or by depressing the
brake pedal, pushing the lever up in the
“+ RES” direction will restore the speed
set prior to cancellation.
However, once the vehicle speed falls be-
low about 40 km/h (25 mph), the preset
speed will not be resumed.
CRUISE CONTROL FAILURE WARNING
If the “CRUISE” indicator light in the
instrument cluster flashes when using the
cruise control, press the “ON
−OFF” button
to turn the system off and then press it
again to turn it on.
If any of the following conditions then oc-
curs, there is some trouble in the cruise
control system.
The indicator light does not come on.
The indicator light flashes again.
The indicator light goes out after it
comes on.
If this is the case, contact your Toyota
dealer and have your vehicle inspected.

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In the following cases, the system may
not work properly.
When ice, snow, mud or other objects
build up on the sensor.
When the vehicle is parked in extreme-
ly high or extremely low temperature
for a long period.
When driving on bumpy or graveled
roads or on grass
When a device such as a horn from
another vehicle, motorcycle engine, or
an air brake sound from a heavy −duty
vehicle, issues ultrasonic waves, near
your vehicle
When attaching a two −way radio anten-
na
When rain or water splashes on the
sensor.
When operating the vehicle on an in-
clined surface
When a radio antenna or fender pole
is mounted on your vehicle.
When a towing hitch is mounted on
your vehicle. The system may not detect the follow-
ing.
Thin objects such as a wire or rope
Objects with a surface area too small
to reflect ultrasonic waves such as
wire gauze
Sound wave absorbing objects or mate-
rial such as cotton or snow
A person near the vehicle (depending
on the type of clothes worn)
Objects with a sharp edge
Small or short objects
Tall objects with an upper part project-
ing toward the vehicle
Objects just under the bumper
Objects very close to your vehicle
In the following cases, have your
Toyota dealer check the system.
When the bumper is damaged.
When the indicator is continuously on.
1: Rear sensors
2: Rear corner sensors
The Toyota park assist system is de-
signed to inform you of the approxi-
mate distance between your vehicle and
an obstruction by indicator and buzzer
while driving at approximate 10 km/h (6
mph) or less when parking the vehicle.
This system uses sensors to detect ob-
structions.
This system works when the ignition key
is at the “ON” position and the transmis-
sion is in the “R” position.
The sensors work only when the transmis-
sion is in the “R” position.
Toyota park assist system
(type B)

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The threeway catalytic converter is an
emission control device installed in the
exhaust system.
The purpose is to reduce pollutants in the
exhaust gas.
CAUTION
Keep people and combustible mate-
rials away from the exhaust pipe
while the engine is running. The
exhaust gas is very hot.
Do not drive, idle or park your ve-
hicle over anything that might burn
easily such as grass, leaves, paper
or rags.
NOTICE
A large amount of unburned gases
flowing into the threeway catalytic
converter may cause it to overheat
and create a fire hazard. To prevent
this and other damage, observe the
following precautions:
Use only unleaded gasoline.
 Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three
way catalytic converter.
 Do not allow the engine to run at
idle speed for more than 20 min-
utes.
 Avoid racing the engine.
 Do not pushstart or pullstart your
vehicle.
 Do not turn off the ignition while
the vehicle is moving.
Keep your engine in good running
order. Malfunctions in the engine
electrical system, electronic ignition
system/distributor ignition system
or fuel system could cause an ex-
tremely high threeway catalytic
converter temperature.
 If the engine becomes difficult to
start or stalls frequently, take your
vehicle in for a checkup as soon
as possible. Remember, your Toyota
dealer knows your vehicle and its
threeway catalytic converter sys-
tem best.
 To ensure that the threeway cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.
Threeway catalytic converter

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CAUTION
Avoid inhaling the engine exhaust.
It contains carbon monoxide, which
is a colorless and odorless gas. It
can cause unconsciousness or even
death.
Make sure the exhaust system has
no holes or loose connections. The
system should be checked from
time to time. If you hit something,
or notice a change in the sound of
the exhaust, have the system
checked immediately.
Do not run the engine in a garage
or enclosed area except for the
time needed to drive the vehicle in
or out. The exhaust gases cannot
escape, making this a particularly
dangerous situation.
Do not remain for a long time in a
parked vehicle with the engine run-
ning. If it is unavoidable, however,
do so only in an unconfined area
and adjust the heating or cooling
system to force outside air into the
vehicle.
Keep the back door and quarter
windows closed while driving. An
open or unsealed back door and
quarter windows may cause exhaust
gases to be drawn into the vehicle.
To allow proper operation of your
vehicle’s ventilation system, keep
the inlet grilles in front of the wind-
shield clear of snow, leaves, or oth-
er obstructions.
If you smell exhaust fumes in the
vehicle, drive with the windows
open and the back door and quarter
windows closed. Have the cause im-
mediately located and corrected.
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of
lubricating and cooling the inside of the
engine, and plays a major role in main-
taining the engine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume some engine oil during normal
engine operation. The causes of oil
consumption in a normal engine are as
follows.
Oil is used to lubricate pistons, piston
rings and cylinders. A thin film of oil
is left on the cylinder wall when a pis-
ton moves downwards in the cylinder.
High negative pressure generated when
the vehicle is decelerating sucks some
of this oil into the combustion chamber.
This oil as well as some part of the oil
film left on the cylinder wall is burned
by the high temperature combustion
gases during the combustion process.
Oil is also used to lubricate the stems
of the intake valves. Some of this oil
is sucked into the combustion chamber
together with the intake air and is
burned along with the fuel. High tem-
perature exhaust gases also burn the
oil used to lubricate the exhaust valve
stems.
Engine exhaust cautionsFacts about engine oil
consumption

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The amount of engine oil consumed de-
pends on the viscosity of the oil, the
quality of the oil and the conditions the
vehicle is driven under.
More oil is consumed by high−speed driv-
ing and frequent acceleration and decel-
eration.
A new engine consumes more oil, since
its pistons, piston rings and cylinder walls
have not become conditioned.
Oil consumption: Max. 1.0 L per 1000
km (1.1 qt./600 miles, 0.9 Imp. qt./600
miles)
When judging the amount of oil con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accurately.
As an example, if a vehicle is used for
repeated short trips, and consumes a nor-
mal amount of oil, the dipstick may not
show any drop in the oil level at all, even
after 1000 km (600 miles) or more. This
is because the oil is gradually becoming
diluted with fuel or moisture, making it
appear that the oil level has not changed.
The diluting ingredients evaporate out
when the vehicle is then driven at high
speeds, as on an express way, making it
appear that oil is excessively consumed
after driving at high speeds. IMPORTANCE OF ENGINE OIL LEVEL
CHECK
One of the most important points in prop-
er vehicle maintenance is to keep the en-
gine oil at the optimum level so that oil
function will not be impaired. Therefore, it
is essential that the oil level be checked
regularly. Toyota recommends that the oil
level be checked every time you refuel
the vehicle.
NOTICE
Failure to check the oil level regularly
could lead to serious engine trouble
due to insufficient oil.
For detailed information on oil level check,
see “Checking the engine oil level” on
page 456 in Section 7
−2.
Your engine is fitted with iridiumtipped
spark plugs.
NOTICE
Use only iridiumtipped spark plugs
and do not adjust gaps for your en-
gine performance smooth driveabili-
ty.
Iridiumtipped spark plugs

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The tandem master cylinder brake system
is a hydraulic system with two separate
sub−systems. If either sub −system s hould
fail, the other will still work. However, the
pedal will be harder to press, and your
stopping distance will increase. Also, the
brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a
single brake system. Have your
brakes fixed immediately.
BRAKE BOOSTER
The brake booster uses engine vacuum to
power −assist the brakes. If the engine
should quit while you are driving, you can
bring the vehicle to a stop with normal
pedal pressure. There is enough reserved
vacuum for one or two stops—but no
more!
CAUTION
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your reserved vacu-
um.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push the
pedal hard, much harder than nor-
mal. And your braking distance will
increase.
ANTILOCK BRAKE SYSTEM (with
“ABS” warning light)
The antilock brake system is designed
to help prevent lockup of the wheels
during a sudden braking or braking on
slippery road surfaces. This assists in
providing directional stability and steer-
ing performance of the vehicle under
these circumstances.
Effective way to press the ABS brake
pedal: When the anti −lock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the anti −lock
brake system work for you, just hold the
brake pedal down more firmly. Do not
pump the brake in a panic stop. This
will result in reduced braking performan-
ce.
The anti −lock brake system becomes op-
erative after the vehicle has accelerated
to a speed in excess of approximately 10
km/h (6 mph). It stops operating when the
vehicle decelerates to a speed below
approximately 5 km/h (3 mph).
Depressing the brake pedal on slippery
road surfaces such as on a manhole cov-
er, a steel plate at a construction site,
joints in a bridge, etc. on a rainy day
tends to activate the anti −lock brake sys-
tem.
You may hear a click or motor sound in
the engine compartment for a few seconds
when the engine is started or just after
the vehicle begins to move. This means
that the anti −lock brake system is in the
self −check mode, and does not indicate a
malfunction.
Brake system

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1. Check the area around the vehicle be-fore entering it.
2. Adjust seat position, seatback angle, seat cushion height, head restraint
height and steering wheel angle.
3. Adjust the inside and outside rear view mirrors.
4. Lock all doors.
5. Fasten seat belts. 1. Apply the parking brake firmly.
2. Turn off unnecessary lights and acces-
sories.
3. Put the selector lever in “P”. If you need to restart the engine while the
vehicle is moving, put the selector le-
ver in “N”. A starter safety device will
prevent the starter from operating if the
selector lever is in any drive position.
4. Depress the brake pedal and hold it to the floor until driving off. Before starting the engine, be sure to fol-
low the instructions in “(a) Before crank-
ing”.
Normal starting procedure
The multiport fuel injection system/sequen-
tial multiport fuel injection system in your
engine automatically controls the proper
air
−fuel mixture for starting. You can start
a cold or hot engine as follows:
With your foot off the accelerator pedal,
crank the engine by turning the key to
“START”. Release it when the engine
starts.
Engine should be warmed up by driving,
not in idle. For warming up, drive with
smoothly turning engine until engine cool-
ant temperature is within normal range.
If the engine stalls...
Simply restart it, using the correct proce-
dure given in normal starting.
If the engine will not start...
See “If your vehicle will not start” on page
406 in Section 4.
Before starting the engine How to start the engine—
(a) Before cranking
(b) Starting the engine