2006 TOYOTA PRIUS check engine

128
Any of the following conditions may oc-
cur, but do not indicate the malfunc-
tion:
The yellow warning light may stay on
for about 60 seconds after the hybrid
system is started. It is normal if it
turns off after a while.
Depressing the brake pedal repeatedly
may turn on the red warning light and
buzzer. It is normal if the light turns off
and the buzzer stops sounding after a
few seconds.
You may hear a small sound in the
engine compartment after the hybrid
system is started or the brake pedal is
depressed repeatedly. This is a pump
pulsating sound of the brake system,
and it is not a malfunction.
You may hear a motor sound in the
engine compartment when the brake
pedal is depressed with the hybrid sys-
tem off.
The brake pedal stroke may be short
when you press the “POWER” switch
with the brake pedal depressed. (b) Driver’s Seat Belt Reminder Light
and Buzzer
The light and buzzer act as a reminder to
buckle up the driver’s seat belt.
Once the “IG −ON” mode is enabled, the
reminder light flashes and the buzzer
sounds if the driver ’s seat belt is not fas-
tened. Unless the driver fastens the belt,
the light continues flashing and the buzzer
sounds 4 to 8 seconds.
If the vehicle speed rises above 20 km/h
(12 mph) without the belt fastened, a
buzzer sounds.
(c) Front Passenger ’s Seat Belt Reminder Light and Buzzer
This light acts as a reminder to have the
front passenger buckle up the seat belt.
Once the “IG −ON” mode is enabled, the
reminder light flashes if a passenger sits
in the front passenger seat and does not
fasten the seat belt. Unless the front pas-
senger fastens the belt, the light continues
flashing.
If the vehicle speed rises above 20 km/h
(12 mph) without the belt fastened, a
buzzer sounds. If luggage or other load is placed on the
front passenger seat, depending on its
weight, causing the reminder light to flash
and buzzer to sound.
(d) Malfunction Indicator Lamp
This lamp comes on when the “IGON”
mode is enabled and goes off after the
hybrid system starts. This means that
the warning light system is operating
properly.
If the lamp remains on or the lamp
comes on while driving, first check the
following:
Empty fuel tank
If the fuel tank is empty, refuel immedi-
ately.
This case is a temporary malfunction. The
malfunction indicator lamp will go off after
taking several driving trips.
If the lamp does not go off even after
several trips, contact your Toyota deal-
er as soon as possible.
There is a problem somewhere in the
engine, hybrid system, throttle control
system or warning light system itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.

134
(a) Charging System Warning Light
When there are problems in the charging
system while the hybrid system is running,
the warning light comes on.
NOTICE
When the charging system warning
light comes on while the hybrid sys-
tem is running, malfunctions may
have occurred. If the warning light
comes on, immediately stop the ve-
hicle in a safe place and contact your
Toyota dealer.
(b) Low Engine Oil Pressure Warning Light
This light warns that the engine oil pres-
sure is too low.
If it stays on while you are driving, pull
off the road to a safe place and stop the
engine immediately. Call a Toyota dealer
or qualified repair shop for assistance.
The light may come on when the oil level
is extremely low. It is not designed to
indicate low oil level, and the oil level
must be checked using the level dipstick.
NOTICE
Do not drive the vehicle with the
warning light on—even for one block.
It may ruin the engine.
(c) High Coolant Temperature Warning Light
The light operates to warn that the hybrid
system is almost over heating.
If it comes on while you are driving, stop
the vehicle and check your hybrid system.
For detailed instructions, see “If your ve-
hicle overheats” on page 360.
Your vehicle may overheat during severe
operating conditions, such as:
Driving up a long hill on a hot day.
Reducing speed or stopping after high
speed driving.
NOTICE
 Do not remove the thermostat in
the cooling system as this may
cause the hybrid system to over-
heat. The thermostat is designed to
control the flow of coolant to keep
the temperature of the hybrid sys-
tem within the specified operating
range.
 Continued driving with the light on
could result in the overheating of
hybrid system.

321
30p001d
The threeway catalytic converters are
emission control devices installed in
the exhaust system.
Its 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 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 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 converters

322
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 hybrid system 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 hybrid sys-
tem running. If it is unavoidable,
however, do so only in an uncon-
fined area and adjust the heating or
cooling system to force outside air
into the vehicle.
Keep the back door closed while
driving. An open or unsealed back
door 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, open the windows and
close the back door to ensure
plenty of fresh air enters the ve-
hicle. If you can smell exhaust
fumes even though there are no
other vehicles in the surrounding
area, have your vehicle checked by
your Toyota dealer. Continued in-
halation of exhaust fumes can lead
to death by gas poisoning.
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
piston moves downwards in the cylin-
der. 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 com-
bustion gases during the combustion
process.
Engine exhaust cautionsFacts about engine oil
consumption

323

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.
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 expressway, 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 400.

324
30p103
Electric water pumpCoolant heat storage
tank
Coolant flow control
valve
The coolant heat storage tank system
stores hot coolant and feeds it via the
electric water pump automatically to warm
the engine as required. This system helps
generate clean emissions. To confirm the
coolant heat storage system check, the
pump may operate automatically with the
vehicle stopped (in the “IG −OFF” mode).
Although the pump may operate and
cause noise while the vehicle is stopped,
this does not indicate a malfunction.
CAUTION
The coolant in this tank is hot even
if the engine and radiator are cold.
For replacement of the coolant,
contact your Toyota dealer.
Do not touch bolts (9 pieces)
painted in yellow.
In case the bolts are loosened,
there is a risk of hot coolant com-
ing out from inside the tank.
When this has any malfunction, the
surface of this tank gets hot. To
prevent burning yourself, do not
touch the tank.
INFORMATION
In such cases as the time of engine
starting and a short trip after the
engine is stopped, the electric water
pump will work for a moment, but
this is no problem.
This is for the preparation for good
emission.
Your engine is fitted with iridiumtipped
spark plugs.
NOTICE
Use only iridiumtipped spark plugs.
Do not adjust gaps for engine perfor-
mance or smooth drivability.
Coolant heat storage system Iridiumtipped spark plugs

348
1. Check the area around the vehicle be-fore entering it.
2. Adjust seat position, seatback angle, head restraint height and steering
wheel angle.
3. Adjust the inside and outside rear view mirrors.
4. Lock all doors.
5. Fasten seat belts.
When you get in the vehicle, check
whether the “READY” light is on or
not.
CAUTION
Your vehicle does not produce any
noise or vibration when the vehicle is
ready to be driven with the “READY”
light on. Move your foot carefully
from the brake pedal to the accelera-
tion pedal when driving.
1. Apply the parking brake firmly.
2. Turn off unnecessary lights and acces- sories.
3. Depress the brake pedal and hold it to the floor until driving off.
40p102b
Before starting the hybrid system, be sure
to follow the instructions in “(a) Before
starting the hybrid system”.
Normal starting procedure
Carry the key and press the “POWER”
switch briefly and firmly with the brake
pedal depressed. The “READY” light starts
blinking. After a few seconds, the blinking
“READY” light remains on and two beeps
sound. (If the ambient temperature is low,
such as during winter driving conditions,
it may take time until the “READY” light
is on.)
The engine may not start even with the
“READY” light on.
Before starting the hybrid
system How to start the hybrid
system— (a) Before starting
the hybrid system
( b ) Tu rn in g on th e hyb rid
system (Using the smart
function—on some models)

351
CAUTION
Before driving off, make sure the
parking brake is fully released and
the parking brake reminder light is
off.
Do not leave your vehicle unat-
tended with the “READY” light on.
Do not rest your foot on the brake
pedal while driving. It can cause
dangerous overheating, needless
wear, and poor fuel economy.
To drive down a long or steep hill,
reduce your speed and downshift.
Remember, if you ride the brakes
excessively, they may overheat and
not work properly.
Be careful when accelerating or
braking on a slippery surface. Sud-
den acceleration or engine braking,
could cause the vehicle to skid or
spin.
Do not drive in excess of the speed
limit. Even if the legal speed limit
permits it, do not drive over 140
km/h (85 mph) unless your vehicle
has highspeed capability tires.
Driving over 140 km/h (85 mph)
may result in tire failure, loss of
control and possible injury. Be sure
to consult a tire dealer to determine
whether the tires on your vehicle
are highspeed capability tires or
not before driving at such speeds.
Do not continue normal driving
when the brakes are wet. If they are
wet, your vehicle will require a lon-
ger stopping distance, and it may
pull to one side when the brakes
are applied. Also, the parking brake
will not hold the vehicle securely.
Make sure you have a proper freeze
protection for engine coolant.
Only use “Toyota Super Long Life Coolant”
or similar high quality ethylene glycol
based non−silicate, non −amine, non− nitrite,
and non− borate coolant with long −life
hybrid organic acid technology. (Coolant
with long −life hybrid organic acid
technology is a combination of low
phosphates and organic acids.)
See “Checking the coolant level” on page
402 for details of coolant type selection.
For the U.S.A.—“Toyota Super Long Life
Coolant” is a mixture of 50% coolant and
50% deionized water. This coolant pro-
vides protection down to about −35 C
( − 31 F).
For Canada—“Toyota Super Long Life
Coolant” is a mixture of 55% coolant and
45% deionized water. This coolant pro-
vides protection down to about −42 C
( − 44 F).
NOTICE
Do not use plain water alone.
Winter driving tips