Hybrid system warning TOYOTA PRIUS 2004 2.G User Guide

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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.

137
25p004c
(d) Using engine braking
To use engine braking, shift the shift lever
to “B” position.
During high speed driving, you may feel
that deceleration by engine braking is less
than that of a typical vehicle.
Do not continue normal driving with the
transaxle in “B” for a long time. This may
cause decreased fuel economy. To prevent
this, use “D” for normal driving.
When you shift the transaxle to “B” from
a position other than “D”, an alarm sounds
and the transaxle is automatically shifted
to “N”.
CAUTION
Be careful when downshifting on a
slippery surface. Abrupt shifting
could cause the vehicle to skid or
spin.
(e) Backing up1. Bring the vehicle to a complete stop.
2. With the brake pedal held down with your foot, shift the shift lever to the
“R” position. You will hear beeps while
the transaxle is in “R”.
When you shift the transaxle to “R” while
driving, an alarm sounds and the transaxle
is shifted to “N”.
(f) Parking 1. Bring the vehicle to a complete stop.
2. With the brake pedal pressed down, fully depress the parking brake pedal
to apply the parking brake securely.
3. With the brake pedal pressed down, push the “P” position switch.
If you press the “POWER” switch while
stopping, the transaxle is automatically
shifted to the “P” and the hybrid system
is turned off. If the driver ’s door is opened when the
transaxle is in “N”, “D” or “B”, beep
sounds and a warning message appears
on the multi
−information display to warn
you to shift the transaxle to “P”.
If you push the “P” position switch while
driving, an alarm sounds and the transaxle
is automatically shifted to “N”.NOTICE
Be sure to put the hybrid transaxle in
“P” when parking. In “N”, the hybrid
vehicle battery will not be charged
even if the gasoline engine is run-
ning. You cannot start your vehicle if
the transaxle is left in “N” for a long
time because the hybrid vehicle bat-
tery will discharge.
When shifting the transaxle from “P” on
the slope, a large parking lock releasing
noise will be generated. However, this
does not indicate a malfunction.

138
(g) Vehicle driving characteristics
Creeping
In order to hold the vehicle properly on an
incline and for better accelerator pedal
operation at starting, your vehicle is de-
signed like a typical automatic transmis-
sion vehicle which tends to move without
depressing the accelerator pedal with the
transaxle in a position other than “P” or
“N”.
With the transaxle in a position other than
“P” or “N”, depress the brake pedal firmly
even when stopped and apply the parking
brake as required.
When moving in a compact area or during
a traffic jam, it is an effective way to
control the speed using only the brake
pedal operation without depressing the ac-
celerator pedal.
Regenerative brake
When the accelerator pedal is released or
the brake pedal is depressed, the electric
motor acts as a generator and converts
kinetic energy to electric energy to provide
deceleration and recover electric energy to
charge the hybrid vehicle battery.
At this time, the electric motor running
noise may increase.The operation is the same as a typical
gasoline powered vehicle.
You may experience the following condi-
tion while braking. As they do not indicate
a malfunction, perform braking as usual:
In the “OFF” mode, pressing the
“POWER” switch once or twice will se-
lect “ACC” or “IG
−ON” only if the brake
pedal is not depressed. In this condi-
tion, the brake pedal may move a little.
Hybrid driving
This vehicle runs in combination with the
gasoline engine and electric motor.
If the “READY” light is on, you can start
your vehicle even with the gasoline engine
stopped. (h) If the system malfunctions
In the following conditions, there is some
problem in the system.
The indicator on the “P” position switch
flashes. However, this does not indi-
cate a malfunction unless a warning
message appears in the multi
−informa-
tion display.
All frames of shift position indicators in
the instrument cluster flash.
The parking system error message ap-
pears on the multi −information display.
The instrument cluster and multi −infor-
mation display does not come on when
the “IG −ON” mode is enabled.
In these cases, stop your vehicle in a
safe and level place, apply the parking
brake securely and contact your Toyota
dealer immediately.
(i) When the auxiliary battery is dis- connected
Before you disconnect the aux iliary bat-
tery, confirm the shift position is “P” and
apply the parking brake completely.
After you reconnect the auxiliary battery,
shift the shift lever to “N” and confirm the
shift position is in “N” when the “IG −ON”
mode is enabled.

209
REGENERATIVE BRAKE
When the brake is applied, the electric
motor used as a generator converts kinet-
ic energy into electric energy.
The regenerative brake works in the fol-
lowing operations.1. When the accelerator pedal is re- leased, the reduced speed equal to en-
gine braking in a gasoline −fueled ve-
hicle is obtained in accordance with the
running mode position of the shift le-
ver.
2. When the brake pedal is depressed with the shift lever in “D” or “B”, the
regenerative brake works. HYDRAULIC BRAKE
This brake system has 3 independent hy-
draulic circuits. If either circuit should fail,
the other will still work. However, the ped-
al will be harder to press, and your stop-
ping 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 ACTUATOR
The brake actuator uses brake fluid pres-
surized by the pump to power
−assist the
brakes. If the brake actuator fails during
driving, the brake system warning light
comes on and buzzer sounds continuous-
ly. In this case, the brakes may not work
properly. If they do not work well, depress
the brake pedal firmly. If the brake system
warning light comes on, immediately stop
your vehicle and contact your Toyota deal-
er. The yellow brake system warning light
may stay on for about 60 seconds after
the “IG
−ON” mode is enabled. It is normal
if the light turns off after a while.
Depressing the brake pedal repeatedly
may turn on the red brake system 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.
In the following conditions, you may hear
a motor sound in the engine compartment.
The brake pedal is depressed when the
hybrid system is turned off.
The driver ’s door is opened.
For a few seconds after the hybrid
system is “OFF” and a bout 90 seconds
have passed.
The brake pedal stroke may be short
when you press the “POWER” switch with
the brake pedal depressed.
Brake system

213
The electric power steering system, us-
ing an electric motor, assists the turn-
ing of the steering wheel.
In the following cases, you may feel the
steering becomes heavy. However, the
electric power steering system warning
light does not come on. (Because it is
not a malfunction.)
When maneuvering the steering fre-
quently or keeping the steering wheel
turned fully while the vehicle is stopped
or moving very slowlyThe power steering effect will be re-
duced to prevent the system from over-
heating. Avoid turning the steering
wheel, or stop the vehicle. When you
leave the vehicle in the “IG −ON” mode
for a while, the system will become
cool.
NOTICE
If you repeat the operation which will
turn on the overheating prevention
function, the electric power steering
system may be damaged.
When the auxiliary battery is dis-
charged
Check the auxiliary battery’s condition.
If necessary, recharge or replace the
battery. For details, see “Checking aux-
iliary battery condition” on page 298.
When the steering wheel is operated
with the hybrid system not to be turned
on (with the “READY” light off)
The auxiliary battery capacity is de-
creased temporarily. The system re-
turns to normal some time after the
hybrid system is turned on.
If there is a problem somewhere in the
electric power steering system, the warn-
ing light comes on in the multi −information
display. For details, see “Multi −information
display” on page 124.30p003
The brake pad wear limit indicators on
your disc brakes give a warning noise
when the brake pads are worn to where
replacement is required.
If you hear a squealing or scraping noise
while driving, have the brake pads
checked and replaced by your Toyota
dealer as soon as possible. Expensive ro-
tor damage can result if the pads are not
replaced when necessary.
Electric power steering system Brake pad wear limit
indicators