2003 TOYOTA PRIUS check engine light

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(a) Brake System Warning Light andBuzzer
This light comes on in the following cases
when the ignition key is in the “ON” posi-
tion.
When the parking brake is applied...
This light comes on for a few seconds
when the ignition key is turned to the
“ON” position even after the parking brake
is released.
When the brake fluid level is low...
CAUTION
It is dangerous to continue driving
normally when the brake fluid level is
low.
When the regenerative brake system
is fails...
When the hydraulic brake booster
fails...
If the hydraulic booster causes a problem
resulting in poor braking performance, the
warning light comes on and buzzer sounds
continuously. Have your vehicle checked at your
Toyota dealer in the following cases:
The light does not come on even if the
parking brake is applied when the igni-
tion key is in the “ON” position.
The light does not come on even if the
ignition key is turned on with the park-
ing brake released.
A warning light turning on briefly during
operation does not indicate a problem.
CAUTION
If any of the following conditions oc-
curs, immediately stop your vehicle at
a safe place and contact your Toyota
dealer.
The light does not turn off even
after the parking brake is released
while the hybrid system is running.
The warning buzzer comes on to-
gether with the warning light.
In either case, this can indicate that
the brakes may not work properly and
your stopping distance will become
longer. Depress the brake pedal firmly
and bring the vehicle to an immediate
stop.
The brake system warning light re-
mains on together with the “ABS”
warning light.
In this case, not only the antilock
brake system will fail but also the
vehicle will become extremely unsta-
ble during braking.
Any of the following conditions may oc-
cur, but do not indicate the malfunc-
tion:
The light may stay on for about 60
seconds after the ignition key is turned
to the “ON” position. It is normal if it
turns off after a while.
Depressing the brake pedal repeatedly
may turn on the 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 p edal is
depressed repeatedly. This is a pump
pulsating sound of the brake system,
and it is not a malfunction.

96
(b) Driver’s Seat Belt Reminder Lightand Buzzer
This light and buzzer remind you to
buckle up the driver’s seat belt.
Once the ignition key is turned to ”ON” or
”START”, the reminder light flashes and
the buzzer sounds if the driver ’s seat belt
is not fastened. Unless the driver fastens
the belt, the light keeps on flashing and
the buzzer sounds 4 to 8 seconds.
(c) Front Passenger ’s Seat Belt Reminder Light
This light reminds you to buckle up the
front passenger ’s seat belt.
Once the ignition key is turned to “ON” or
“START”, the reminder light flashes if a
passenger sits in the front passenger seat
and does not fasten the seat belt. Unless
the front passenger fastens the belt, the
light stays flashing.
If luggage load is placed on the front
passenger seat, depending on its weight
and how it is placed on the seat, builtin
sensors in the seat cushion may detect
the pressure, causing the reminder light to
come on. (d) Discharge Warning Light
This light warns that the auxiliary battery
is being discharged.
If it comes on while you are driving, there
is a problem somewhere in the charging
system.
The hybrid system will continue to oper-
ate, however, until the auxiliary battery is
discharged. Turn off the air conditioning,
blower, radio, etc., and drive directly to
the nearest Toyota dealer or repair shop.
(e) Malfunction Indicator Lamp
This lamp comes on when the ignition
key is turned to the “ON” position and
goes off after the engine 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 will not go off even after
several trips, contact your Toyota deal-
er as soon as possible.
There is a problem somewhere in the
hybrid system or warning light system
itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.

97
Emissions inspection and maintenance
(I/M) programs
Your vehicle may not pass a state emis-
sion inspection if the malfunction indicator
lamp remains on. Contact your Toyota
dealer to check your vehicle’s emission
control system and OBD (OnBoard Diag-
nostics) system before taking your vehicle
for the inspection.
For details, see “Emissions inspection and
maintenance (I/M) programs” on page 204
in Section 7.
(f) Master Warning Light
()
If the master warning light comes on, the
warning light for the faulty system is high-
lighted or the message such as “When
you park your car, make sure you shift to
Park P.” and “The batteries will not charge
if the shifter is in N” appears on the mul-
tiinformation display. (See “Service re-
minder indicators and warning buzzers—
—Multiinformation display” on page 100
in this section or “Precautions for use” on
page 12 in Section 12 or “Fuel gauge”
on page 89 in Section 24 for instruc-
tions.)(g) Output Control Warning Light
()
This light comes on when the ignition
switch is on. It goes off when the electric
motor is ready to run.
The warning light comes on when the hy-
brid vehicle battery temperature is low or
high, or the hybrid vehicle battery capacity
is decreased with the selector lever at “R”
during driving. If the light comes on, the
power will be limited. Drive your vehicle
without hard acceleration.
(h) Low Engine Oil Pressure Warning
Light
This light warns that the engine oil pres-
sure is too low.
If it flickers or 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 occasionally flicker when
the engine is idling or it may come on
briefly after a hard stop. There is no
cause for concern if it then goes out when
the engine is accelerated slightly.
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.
(i) “ABS” Warning Light
The light comes on when the ignition key
is turned to the “ON” position. If the anti
lock brake system works properly, the
light turns off after a few seconds. There-
after if the system malfunctions, the light
comes on again.
When the “ABS” warning light is on (and
the brake system warning light is off), the
antilock brake system does not operate,
but the brake system still operates con-
ventionally.
When the “ABS” warning light is on (and
the brake system warning light is off), the
antilock brake system does not operate
so that the wheels could lock up during
a sudden braking or braking on slippery
road surfaces.
If either of the following conditions
occurs, this indicates a malfunction
somewhere in the parts monitored by
the warning light system. Contact your
Toyota dealer as soon as possible so
service the vehicle.

167
When the ignition switch is turned to on
or off, you may hear a sound coming from
the hybrid vehicle battery in the trunk.
However, this does not indicate any
trouble.
NOTICE
The “READY” light does not come on
when the selector lever is put in a
position other than “P”. Depress the
brake pedal and put the selector lever
in “P” and turn the ignition switch to
“START” again.
If there is a problem somewhere in the
hybrid system, the hybrid system malfunc-
tion warning light will come on in place of
the “READY” light. If this happens, contact
Toyota dealer.
NOTICE
When you start the hybrid system at
a lowered outside temperature, it may
take longer before the blinking
“READY” light changes to stay on.
Always slow down in gusty crosswinds.
This will allow you much better control.
Drive slowly onto curbs and, if pos-
sible, at a right angle. Avoid driving
onto high, sharpedged objects and
other road hazards. Failure to do so
can lead to severe tire damage result-
ing in tire bursts.
Drive slowly when passing over bumps
or travelling on a bumpy road. Other-
wise, the impact could cause severe
damage to the tires and/or wheels.
When parking on a hill, turn the front
wheels until they touch the curb so
that the vehicle will not roll. Apply the
parking brake, and put the selector le-
ver into “P”. If necessary, block the
wheels.
Washing your vehicle or driving through
deep water may get the brakes wet. To
see whether they are wet, check that
there is no traffic near you, and then
press the pedal lightly. If you do not
feel a normal braking force, the brakes
are probably wet. To dry them, drive
the vehicle cautiously while lightly
pressing the brake pedal with the park-
ing brake pulled. If they still do not
work safely, pull to the side of the road
and call a Toyota dealer for assistance.
CAUTION
Before driving off, make sure the
parking brake is fully released and
that 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 spin or
skid.
Tips for driving in various
conditions123.

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If your hybrid system 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. Turn the ignition switch to ”OFF” posi- tion, and try starting the hybrid system
again.
If the hybrid system will not start, see “If
your vehicle will not start” on page 172.
CAUTION
If the hybrid system is not operating,
the power assist for the brakes and
steering will not work so steering and
braking will be much harder than usu-
al.
If your high coolant temperature warn-
ing light comes on, if you experience a
loss of power, or if you hear a loud
knocking or pinging noise, the hybrid
system has probably overheated. You
should follow this procedure... 1. Pull safely off the road, stop the ve- hicle and turn on your emergency
flashers. Put the transmission in “P”
and apply the parking brake. Turn off
the air conditioning if it is being used.
2. If coolant or steam is boiling out of the radiator or reservoir, stop the hybrid
system. Wait until the steam subsides
before opening the hood. If there is no
coolant boiling over or steam, leave the
hybrid system running and make sure
the electric cooling fan is operating. If
it is not, turn the ignition off.
CAUTION
To help avoid personal injury, keep
the hood closed until there is no
steam. Escaping steam or coolant is
a sign of very high pressure.
3. Look for obvious coolant leaks from theradiator, hoses, and under the vehicle.
However, note that water draining from
the air conditioning is normal if it has
been used.
CAUTION
When the hybrid system is running,
keep hands and clothing away from
the moving fan and engine drive
belts.
4. If the coolant is leaking, stop the hy-brid system immediately. Call a Toyota
dealer for assistance.
5. If there are no obvious leaks, check the coolant reservoir. If it is dry, add
coolant to the reservoir while the hy-
brid system is running. Fill it about half
full.
CAUTION
Do not attempt to remove the radiator
cap when the hybrid system and ra-
diator are hot. Serious injury could
result from scalding hot fluid and
steam blown out under pressure.
If your hybrid system stalls
while driving130. 131.If your vehicle overheats

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INSIDE THE VEHICLE
Items listed below should be checked
regularly, e.g. while performing periodic
services, cleaning the vehicle, etc.
Lights
Make sure the headlights, stop lights, tail
lights, turn signal lights, and other lights
are all working. Check headlight aim.
Service reminder indicators and warning
buzzers
Check that all service reminder indicators
and warning buzzers function properly.
Steering wheel
Be alert for changes in steering condition,
such as hard steering or strange noise.
Seats
Check that all front seat controls such as
seat adjusters, seatback recliner, etc. op-
erate smoothly and that all latches lock
securely in any position. Check that the
head restraint move up and down smooth-
ly and that the locks hold securely in any
latched position.Seat belts
Check that the seat belt system such as
buckles, retractors and anchors operate
properly and smoothly. Make sure the belt
webbing is not cut, frayed, worn or dam-
aged.
Accelerator pedal
Check the pedal for smooth operation and
uneven pedal effort or catching.
Brake pedal
Check the pedal for smooth operation and
that the pedal has the proper clearance.
Check the brake booster function.
Brakes
At a safe place, check that the brakes do
not pull to one side when applied.
Parking brake
Check that the pedal has the proper travel
and that, on a safe incline, your vehicle
is held securely with only the parking
brake applied.
Hybrid transaxle ”Park” mechanism
Check the lock release button of the se-
lector lever for proper and smooth opera-
tion. On a safe incline, check that your
vehicle is held securely with the selector
lever in ”P” position and all brakes re-
leased.
IN THE ENGINE COMPARTMENT
Items listed below should be checked
from time to time, e.g. each time when
refueling.
Washer fluid
Make sure there is sufficient fluid in the
tank. See page 231 in Section 83 for
additional information.
Coolant level
Make sure the coolant level is between
the ”FULL” and ”LOW” lines on the see
through reservoir when the hybrid system
is cold. See page 216 in Section 82 for
additional information.
Radiator, condenser and hoses
Check that the front of the radiator and
condenser are clean and not blocked with
leaves, dirt, or insects. See page 218 in
Section 82 for additional information.

211
153.Parts and tools
Here is a list of parts and tools you will
need on performing doityourself mainte-
nance. Remember all Toyota parts are de-
signed in metric sizes, so your tools must
be metric.
CHECKING THE ENGINE OIL LEVEL
Parts (if level is low):
Engine oil API grade SL “EnergyCon-
serving” or ILSAC multigrade having
viscosity proper for your climate
Tools:
Rag or paper towel
Funnel (only for adding oil)
CHECKING THE COOLANT LEVEL
Parts (if level is low):
”Toyota Genuine Long Life Coolant” or
equivalent
See page 217 in Section 82 for de-
tails about coolant type selection.
Demineralized or distilled water
Tools:
Funnel (only for adding coolant) CHECKING BRAKE FLUID
Parts (if level is low):
SAE J1703 or FMVSS No.116 DOT 3
brake fluid
Tools:
Rag or paper towel
Funnel (only for adding fluid)
CHECKING AUXILIARY BATTERY CON-
DITION
Tools:
Warm water
Baking soda
Grease
Conventional wrench (for terminal
clamp bolts)
CHECKING AND REPLACING FUSES
Parts (if replacement is necessary):
Fuse with same amperage rating as
original
ADDING WASHER FLUID
Parts:
Water
Washer fluid containing antifreeze (for
winter use) Tools:
Funnel
REPLACING LIGHT BULBS
Parts:
Bulb with same number and wattage
rating as original (See charts in ”Re-
placing light bulbs–” on page 231 in
Section 83.)
Tools:
Screwdriver

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82p001a
Low level Full level
Add oil O.K. Too full
With the hybrid system at operating
temperature and turned off, check the
oil level on the dipstick. 1. To get a true reading, the vehicle should be on a level spot. After turning
off the hybrid system, wait a few min-
utes for the oil to drain back into the
bottom of the engine.
2. Pull the dipstick out, hold the rag un- der the end and wipe it clean.
3. Reinsert the dipstick—push it in as far as it will go, or the reading will not be
correct. 4. Pull the dipstick out and look at the oil
level while holding a rag under the
end.
CAUTION
Be careful not to touch the hot ex-
haust manifold.
NOTICE
Be careful not to drop the engine oil
on the vehicle components.
If the oil level is below or only slightly
above the low level, add engine oil of
the same type as already in the engine.
Remove the oil filler cap and add engine
oil in small quantities at a time, checking
the dipstick. We recommend that you use
a funnel when adding oil.
The approximate quantity of oil needed to
fill between the low level and the full level
on the dipstick is indicated below for ref-
erence.
When the level reaches within the correct
range, install the f iller cap handtight.
Oil quantity, L (qt., Imp. qt.): 1.5 (1.6, 1.3)
NOTICE
Be careful not to spill the engine
oil on the vehicle components.
 Avoid overfilling, or the hybrid sys-
tem could be damaged.
 Check the oil level on the dipstick
once again after adding the oil.
Checking the engine oil
level155.