2004 TOYOTA PRIUS Hybrid system warning

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(a) Brake System Warning Lights andBuzzer
These lights come on in the following
cases when the “IG −ON” mode is enabled.
RED WARNING LIGHT
When the parking brake is applied...
This light comes on when the “IG −ON”
mode is enabled, 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.
YELLOW WARNING LIGHT
When the regenerative brake system
is fails...
RED OR YELLOW WARNING LIGHT
When the hydraulic brake system
fails...
When the yellow warning light comes on,
it is no problem to continue driving. How-
ever, if the red warning light comes on,
it indicates a serious problem and you can
continue driving no longer. Have your vehicle checked at your
Toyota dealer in the following cases:
The lights do not come on even if the
parking brake is applied when the
“READY” light is on.
The lights do not come on even if the
“POWER” switch is pressed with the
parking brake released.
A red warning light turning on briefly dur-
ing 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 red warning light does not turn
off even after the parking brake is
released while the hybrid system is
running.
The red warning light comes on or
buzzer sounds continuously.
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”
and “VSC” warning light.
In this case, not only the antilock
brake system and vehicle stability
control system will fail but also the
vehicle will become extremely unsta-
ble during braking.
In the following case, drive directly to
the nearest Toyota dealer.
The yellow warning light comes on
while driving.

120
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 “IG−ON”
mode is enabled. 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 p edal 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
This light and buzzer remind you 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 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 “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 stays
flashing.
If luggage or other load is placed on the
front passenger seat, depending on its
weight and how it is placed on the seat,
built −in sensors in the seat cushion may
detect the pressure, causing the reminder
light to come on. (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
hybrid system or warning light system
itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.

121
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 (On−Board Diag-
nostics) system before taking your vehicle
for the inspection.
For details, see “Emissions inspection and
maintenance (I/M) programs” on page 272.
(e) 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 “Please
press “P” to engage Park.” and “The bat-
teries will not be charged if the transaxle
is in Neutral N.” appears on the multi −in-
formation display. (See “Service reminder
indicators and warning buzzers— —Multi −
information display” on page 124 or “Pre-
cautions for use” on page 12 or “Fuel
gauge” on page 114 for instructions.) (f) “ABS” Warning Light
The light comes on when the “IG
−ON”
mode is enabled. If the anti −lock brake
system and the brake assist system work
properly, the light turns off after the
“READY” light comes on. Thereafter 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
anti −lock 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
anti −lock brake system does not operate
but the brake assist system still operates.
In this case, 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.
The light does not come on when the
“IG −ON” mode is enabled, or the light
remains on after the “READY” light
comes on.
The light comes on while you are driv-
ing.
A warning light turning on briefly during
operation does not indicate a problem.
CAUTION
If the “ABS” warning light remains on
together with the red brake system
warning light, immediately stop your
vehicle at a safe place and contact
your Toyota dealer.
In this case, not only the antilock
brake system will fail but also the
vehicle will become extremely unsta-
ble during braking.
Either of the following conditions may
occur, but does not indicate the mal-
function:
The light may stay on for about 60
seconds after the hybrid system is
started. It is normal if it turns off after
a whi l e.

122
Depressing the brake pedal repeatedly
may turn on the light. It is normal if
it turns off after a few seconds.
(g) SRS Warning Light
This light will come on when the “IG
ON” mode is enabled. After about 6
seconds, the light will go off. This
means the system of the airbag and
front seat belt pretensioners are operat-
ing properly.
The warning light system monitors the air-
bag sensor assembly, front airbag sen-
sors, side and curtain shield airbag sen-
sors, curtain shield airbag sensors,
driver ’s seat position sensor, driver ’s seat
belt buckle switch, front passenger ’s seat
belt buckle switch, seat belt pretensioner
assemblies, warning light, interconnecting
wiring and power sources.
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 to service the vehicle.
The light does not come on when the
“IG −ON” mode is enabled or remains
on for more than 6 seconds.
The light comes on while driving. (h) Open Door Warning Light
This light remains on until all the doors
are completely closed.
(i) Low Fuel Level Indicator Light
This light blinks when the fuel level in the
tank becomes nearly empty. Fill up the
tank as soon as possible.
At the first blinking of the light, the mes-
sage appears on the display to remind the
driver to fill fuel.
Contact your Toyota dealer in the following
case:
All the segments blink.
(j) Engine Oil Replacement Reminder Light (for vehicles sold in U.S.A.)
This light reminds you when to replace
the engine oil.
This light will come on when the “IG −ON”
mode is enabled, and will go off after
about a few seconds. When you drive for about 7200 km (4500
miles) after engine oil replacement, this
light illuminates for about 3 seconds and
then flashes for about 12 seconds when
the hybrid system is in the “IG
−ON”
mode. If you continue driving without en-
gine oil replacement, and if the driving
range exceeds 8000 km (5000 miles), the
light will come on after the “IG −ON” mode
is enabled. The light will remain on there-
after.
If the light is flashing, we recommend that
you replace the engine oil at an early
opportunity depending on the driving and
road conditions. If the light comes on,
replace the oil as soon as possible.
The system must be reset after the en-
gine oil replacement. Reset the system by
the following procedure:
1. Press the “POWER” switch to the “OFF” mode
with the odometer reading
shown. (For details, see “Odometer and
two trip meters” on page 115.)
2. Press the “POWER” switch twice to select the “IG −ON” mode while holding
down the trip meter reset button.

123
Hold down the button for at least 5 sec-
onds. The odometer indicates “000000”
and the light goes off.
If the system fails to reset, the light will
remain flashing.
(k) “VSC” warning light
This light warns that there is a problem
somewhere in the vehicle stability control
system.
The light will come on when the “IG−ON”
mode is enabled and will go off after the
“READY” light comes on.
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 “IG −ON” mode is enabled.
The warning light remains on after the
“READY” light comes on.
The warning light comes on while you
are driving.
CAUTION
If the “VSC” warning light remains on
together with the red brake system
warning light, immediately stop your
vehicle at a safe place and contact
your Toyota dealer.
In this case, not only the vehicle sta-
bility control system will fail but also
the vehicle will become extremely un-
stable during braking.
(l) Key Reminder Buzzer
This buzzer reminds you to remove the
key if you open the driver’s door when the
hybrid system is off and the key is in-
serted into the key slot.
(m) Shift Position Reminder Buzzer
This buzzer will sound if the driver ’s door
is opened while the hybrid transaxle is in
“N”, “D” or “B”. CHECKING SERVICE REMINDER INDICA-
TORS (except the low fuel level indica-
tor light)
1. Apply the parking brake.
2. Open one of the doors. The open door warning light should
come on.
3. Close the door. The open door warning light should go
off.
4. Press the “POWER” switch twice with- out pressing the brake pedal to select
the “IG −ON” mode. At this time, all the
bulbs are checked in self −diagnosis
mode.
All the service reminder indicators ex-
cept the open door warning light come
on. The yellow brake system, “ABS”
and “VSC” warning lights go off after
a few seconds.
There may be the case that the yellow
brake system, “ABS” and “VSC” warning
lights stay on for about 60 seconds after
the “IG −ON” mode is enabled. It is normal
if they go out after a while.
If any service reminder indicator or warn-
ing buzzer does not function as described
above, have it checked by your Toyota
dealer as soon as possible.

126
(a) 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.(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 242.
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.

127
(d) Electric Power Steering SystemWarning Light
This light comes on when the power
steering control system fails.
CAUTION
If this light comes on, take your ve-
hicle to the Toyota dealer as soon as
possible. In this case, you may feel
the heavy steering wheel maneuver-
ing. Drive your vehicle while gripping
the steering wheel firmly.
(e) Hybrid System Warning Light ()
This light comes on if there is a problem
in the electric motor, inverter unit, hybrid
vehicle battery, etc.
If this light is on, stop your vehicle in a
safe place immediately and contact your
Toyota dealer.
Even if the hybrid system warning light
comes on, you can temporarily increase
the vehicle speed by depressing the ac-
celerator pedal. Immediately pull up your
vehicle to a safe place and contact your
Toyota dealer. (f) Hybrid Vehicle Battery Warning
Light
This light comes on in the following
cases.
a. The hybrid vehicle battery voltage
drops when the hybrid transaxle is left in
“N” position.
The system works properly if you put the
hybrid transaxle in “P” position and the
light goes off.
b. The hybrid vehicle battery is dis-
charged.
If this light comes on with the “READY”
light on in case of b., stop your vehicle
in a safe place and contact your Toyota
dealer.
(g) Automatic Headlight Leveling Sys- tem Warning Light
This light warns that there is a problem
somewhere in the automatic headlight
leveling system.
If it comes on, have your vehicle checked
by your Toyota dealer,

134
NOTICE
The hybrid system cannot be
started when the shift position is in
“N”. Be sure to put it in “P” and
then start the system.
 Do not leave the hybrid system in
“ACC” or “IGON” for a long time.
The auxiliary battery will discharge.
 The hybrid mode in which the bat-
tery is discharged or disconnected
is retained in memory, and that
mode is turned on when power is
applied.
When you leave your vehicle, be sure to
turn the “POWER” switch off and carry the
smart key.
If you get out of your vehicle while carry-
ing a key without turning off the “POWER”
switch and then close the door, a warning
tone sounds inside and beeps sound out-
side.
INFORMATION
You can insert a genuine key while in
the “IGON” mode or with the hybrid
system starting. Do not insert any key
other than genuine keys.