2004 TOYOTA PRIUS brake

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

210
CAUTION
Do not pump the brake pedal if the
hybrid system is not operating.
Each push on the pedal uses up
your reserved brake fluid pressure.
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
The antilock brake system is designed
to automatically help prevent lockup of
the wheels during a sudden braking or
braking on slippery road surfaces. This
assists in providing directional stability
and steering 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, the slip indicator in
the instrument cluster flashes and you
will 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
performance.
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.
When the antilock brake system is ac-
tivated, the following condition may oc-
cur. They do not indicate a malfunction
of the system:
You may hear the anti −lock brake sys-
tem operating and the vibrations of the
vehicle body and steering wheel. You
may also hear the motor sound in the
engine compartment even after the ve-
hicle is stopped.

211
CAUTION
Do not overestimate the antilock
brake system: Although the antilock
brake system assists in providing ve-
hicle control, it is still important to
drive with all due care and maintain
a moderate speed and safe distance
from the vehicle in front of you, be-
cause there are limits to the vehicle
stability and effectiveness of steering
wheel operation even with the anti
lock brake system on.
If tire grip performance exceeds its
capability, or if hydroplaning occurs
during high speed driving in the rain,
the antilock brake system does not
provide vehicle control.
Antilock brake system is not de-
signed to shorten the stopping dis-
tance: Always drive at a moderate
speed and maintain a safe distance
from the vehicle in front of you.
Compared with vehicles without an
antilock brake system, your vehicle
may require a longer stopping dis-
tance in the following cases:
Driving on rough, gravel or snow
covered roads.
Driving with tire chains installed.
Driving over the steps such as the
joints on the road.
Driving on roads where the road
surface is pitted or has other differ-
ences in surface height.
Install all 4 tires of specified size at
appropriate pressure: The antilock
brake system detects vehicle speeds
using the speed sensors for respec-
tive wheels’ turning speeds. The use
of tires other than specified may fail
to detect the accurate turning speed,
resulting in a longer stopping dis-
tance.
30p002b
Vehicle sold in U.S.A.
30p007b
Vehicle sold in Canada

212
“ABS” warning light
The light comes on when the “IGON”
mode is enabled. If the antilock brake
system works 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
so that the wheels could lock up during
a sudden braking or braking on slippery
road surfaces.
If either of the following conditions oc-
curs, this indicates a malfunction some-
where in the components 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 the
“READY” light remains 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 a malfunc-
tion:
The light may stay on for about 60
seconds after the “IG
−ON” mode is en-
abled. It is normal if it turns off after
a whi l e.
Depressing the brake pedal repeatedly
may turn on the light. It is normal if
it turns off after a few seconds. BRAKE ASSIST SYSTEM
When you slam the brakes on, the
brake assist system judges as an emer-
gency stop and provides more powerful
braking for a driver who cannot hold
down the brake pedal firmly.
When you slam the brakes on, more pow-
erful braking will be applied. At this time,
you may hear a sound in the engine
compartment. This does not indicate a
malfunction.
The brake assist system becomes opera-
tive 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).
For an explanation of this system’s warn-
ing light, see “Service reminder indicators
and warning buzzers” on page 117.

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

221
Ti r e relat ed ter m
Meaning
Cold tire inflation pressuretire inflation pressure when the vehicl
e has been parked at least 3 hours or
more, or it has not been driven more t han 1.5 km or 1 mile under that condition
Maximum inflation pressurethe maximum cold inflation pressure to which a tire may be inflated and shown
on the sidewall of the tire
Recommended inflation pressurecold tire inflation pressure recommended by a manufacturer
Accessory weight
the combined weight (in excess of those standard items which may be replaced)
of automatic transmission, power steering, power brakes, power windows, pow-
er seats, radio, and heater, to the extent that these items are available as
factory−installed equipment (whether installed or not)
Curb weight
the weight of a motor vehicle with standard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so equipped, air conditioning and addi-
tional weight optional engine
Maximum loaded vehicle weight
t he sum of —
(a) curb weight;
(b) accessory weight;
(c) vehicle capacity weight; and
(d) production options weight
Normal occupant weight68 kg (150 lb.) times the number of occupants specified in the second column
of Table 1 that follows
—Glossary of tire terminology

222Ti r e relat ed ter m
Meaning
Production options weight
the combined weight of those installed regular production options weighing over
2.3 kg (5 lb.) in excess of those standard items which they replace, not pre-
viously considered in curb weight or accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty battery, and special trim
Vehicle capacity weight
(Total load capacity)the rated cargo and luggage load plus 68 kg (150 lb.) times the vehicle’s desig-
nated seating capacity
Intended outboard sidewall
(A) the sidewall that contains a whitewall, bears white lettering or bears
manufacturer, brand, and/or model name molding that is higher or deeper
than the same molding on the other sidewall of the tire, or
(B) the outward facing sidewall of an asymmetrical tire that has a particular side that must always face outward when mounted on a vehicle
Occupant distributiondistribution of occupants in a vehicle as specified in the third column of Table
1 that follows
Rima metal support for a tire or a tire and tube assembly upon which the tire beads
are seated
Rim diameter (Wheel diameter)nominal diameter of the bead seat
Rim size designationrim diameter and width
Rim type designationthe industry of manufacturer ’s designation for a rim by style or code
Rim widt hnominal distance between rim flanges
Vehicle maximum load on the tirethe load on an individual tire that is determined by distributing to each axle
its share of the maximum loaded vehicle weight and dividing by two

230
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.
40p002b
Before starting the hybrid system, be sure
to follow the instructions in “(a) Before
starting the hybrid system”.
Normal starting procedure
Insert 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 a beep
sounds. (If the ambient temperature is
low, such as during winter driving condi-
tions, 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 key)