
416
PRIUS_OM_OM47F01U_(U)
4-5. Using the driving support systems
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when start -
ing on an uphill
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆E-Four (Electronic On-Demand AWD system) (AWD models)
Automatically switches from fron t-wheel drive to all-wheel drive
(AWD) according to the driving conditions, helping to ensure re li-
able handling and stability. Ex amples of conditions where the s ys-
tem will switch to AWD are when cornering, going uphill, starting off
or accelerating, and when the road surface is slippery due to s now,
rain, etc.
The slip indicator light will flash
while the TRAC/VSC/ABS sys-
tems are operating.
When the TRAC/VSC/ABS systems are operating

418
PRIUS_OM_OM47F01U_(U)
4-5. Using the driving support systems
■Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations:
● Shift the shift position to P or N
● The accelerator pedal is depressed
● The parking brake is engaged
● No more than 2 seconds have elapsed after the brake pedal is re leased.
■ Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and
hill-start assist control systems
●A sound may be heard from the engine compartment when the brake pedal
is depressed repeatedly, when the hybrid system is started or just after the
vehicle begins to move. This sound does not indicate that a mal function has
occurred in any of these systems.
● Any of the following conditions may occur when the above system s are
operating. None of these indicates that a malfunction has occur red.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a s top.
■ ECB operating sound
ECB operating sound may be heard in the following cases, but it does not
indicate that a malfunction has occurred.
● Operating sound heard from the engine compartment when the brak e pedal
is operated.
● Motor sound of the brake system heard from the front part of th e vehicle
when the driver’s door is opened.
● Operating sound heard from the engine compartment when one or t wo min-
utes passed after the stop of the hybrid system.
■ Active Cornering Assist operation sounds and vibrations
When the Active Cornering Assist is operated, operation sounds and vibra-
tions may be generated from the brake system, but this is not a malfunction.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring so und) may be
heard. This does not indicate a malfunction.
■ Automatic reactivation of TRAC and VSC systems
After turning the TRAC and VSC systems off, the systems will be automati-
cally re-enabled in the following situations:
● When the power switch is turned off
● If only the TRAC system is turned off, the TRAC will turn on wh en vehicle
speed increases
If both the TRAC and VSC systems are turned off, automatic re-e nabling
will not occur when vehicle speed increases.

420
PRIUS_OM_OM47F01U_(U)
4-5. Using the driving support systems
WARNING
■The ABS does not operate effectively when
● The limits of tire gripping performance have been exceeded (such as
excessively worn tires on a snow covered road).
● The vehicle hydroplanes while driving at high speed on wet or s lick roads.
■ Stopping distance when the ABS is operating may exceed that of nor-
mal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always
maintain a safe distance from the vehicle in front of you, especially in the
following situations:
● When driving on dirt, gravel or snow-covered roads
● When driving with tire chains
● When driving over bumps in the road
● When driving over roads with potholes or uneven surfaces
■ TRAC/VSC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRAC/VSC system is operating. D rive the
vehicle carefully in conditions where stability and power may be lost.
■ Active Cornering Assist does not operate effectively when
● Do not overly rely on Active Cornering Assist. Active Cornering Assist may
not operate effectively when accelerating down slopes or driving on slip-
pery road surfaces.
● When Active Cornering Assist frequently operates, Active Cornering
Assist may temporarily stop operating to ensure proper operatio n of the
brakes, TRAC and VSC.
■ Hill-start assist control does not operate effectively when
● Do not overly rely on hill-start assist control. Hill-start ass ist control may
not operate effectively on steep inclines and roads covered wit h ice.
● Unlike the parking brake, hill-start assist control is not inte nded to hold the
vehicle stationary for an extended period of time. Do not attempt to use
hill-start assist control to hold the vehicle on an incline, as doing so may
lead to an accident.
■ When the TRAC/ABS/VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may
cause an accident. Exercise particular care when the indicator light flashes.

PRIUS_OM_OM47F01U_(U)
4214-5. Using the driving support systems
4
Driving
WARNING
■When the TRAC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the r oad condi-
tions. As these are the systems to help ensure vehicle stability and driving
force, do not turn the TRAC/VSC systems off unless necessary.
■ Replacing tires
Make sure that all tires are of the specified size, brand, trea d pattern and
total load capacity. In addition, make sure that the tires are inflated to the
recommended tire inflation pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires
are installed on the vehicle.
Contact your Toyota dealer for further information when replaci ng tires or
wheels.
■ Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspensio n will affect
the driving assist systems, and may cause a system to malfunction.

PRIUS_OM_OM47F01U_(U)
5256-3. Do-it-yourself maintenance
6
Maintenance and care
Remove the reservoir cap.
Add brake fluid slowly while checking the fluid level.
Make sure to check the fluid type and prepare the necessary ite m.
■Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss o f braking effi-
ciency. Use only newly opened brake fluid.
3
4
Fluid type SAE J1703 or FMVSS No.116 DOT 3 brake fluid
SAE J1704 or FMVSS No.116 DOT 4 brake fluid
ItemsClean funnel
WARNING
■
When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage
painted surfaces.
If fluid gets on your hands or in your eyes, flush the affected area with clean
water immediately.
If you still experience discomfort, see a doctor.
NOTICE
■ If the brake fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads
wear out or when the fluid level in the accumulator is high.
If the reservoir needs frequent refilling, there may be a serious problem.

5897-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
7
When trouble arises
SRS warning lightIndicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
Have the vehicle inspected by your Toyota dealer
immediately.
(U.S.A.)
(Canada)
ABS warning light Indicates a malfunction in:
• The ABS; or
• The brake assist system
Have the vehicle inspected by your Toyota dealer
immediately.
(Red/yellow)
Electric power steering system warning light (warning
buzzer)
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
Have the vehicle inspected by your Toyota dealer
immediately.
(Flashes or
illuminates)
(If equipped)
PCS warning light
• When a buzzer sounds simultaneously:Indicates a malfunction has occurred in the PCS (Pre-
Collision System).
Have the vehicle inspected by your Toyota dealer
immediately.
• When a buzzer does not sound: The PCS (Pre-Collision System) has become temporar-
ily unavailable, corrective action may be necessary.
Follow the instructions dis played on the multi-infor-
mation display. ( P. 289, 605)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability
Control) system is disabled, the PCS warning light will illu-
minate.
P. 301
(Orange)
(If equipped)
LTA indicator (warning buzzer)
Indicates a malfunction in the LTA (Lane Tracing Assist)
Follow the instructions dis played on the multi-infor-
mation display. ( P. 316)
Warning lightWarning light/Details/Actions

5907-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
Slip indicator lightIndicates a malfunction in:
• The VSC system;
• The TRAC system; or
• The hill-start assist control system
Have the vehicle inspected by your Toyota dealer
immediately.
The light will flash when the ABS, VSC or TRAC system is
operating.
High coolant temperature warning light • When the light flashes:
Indicates that the engine coolant temperature is too high
The light changes from a flashing to a solid light when
the temperature further increases
Immediately stop the vehicle in a safe place. ( P. 652)
• When the light comes on without flashing: Indicates a malfunction in the exhaust heat recirculator
system
Have the vehicle inspected by your Toyota dealer
immediately.
(Flashes)
(If equipped)
PKSB OFF indicator
Indicates a malfunction in the Parking Support Brake func-
tion
Have the vehicle inspected by your Toyota dealer.
The warning light will operate as follows, even when the
system is not malfunctioning:
• The light will come on when the Parking Support Brake function is turned off ( P. 372)
• The light will come on when the Parking Support Brake function is operating ( P. 376)
• The light will flash when the system cannot be temporar- ily used ( P. 378)
Open door warning light (warning buzzer)*3
Indicates that a door is not fully closed
Check that all the doors are closed.
Low fuel level warning light
Indicates that remaining fuel is approximately 1.7 gal.
(6.4 L, 1.4 Imp.gal.) or less
Refuel the vehicle.
Warning lightWarning light/Details/Actions

6017-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
7
When trouble arises
■Warning messages
The warning messages explained below may differ from the actual messages
according to operation conditions and vehicle specifications.
■ System warning lights
The master warning light does not come on or flash in the following cases.
Instead, a separate system warning light will come on along wit h a message
or image shown on the multi-information display.
● “Antilock Brake System Malfunction Visit Your Dealer”:
The ABS warning light comes on. ( P. 589)
● “Braking Power Low Visit Your Dealer”:
The brake system warning light (yellow) will come on. ( P. 588)
● Indicates that a door is not fully closed while the vehicle is stopped.:
The Open door warning light comes on. ( P. 590)
■ If “Visit Your Dealer” is shown
The system or part shown on the multi-information display is malfunctioning.
Have the vehicle inspected by your Toyota dealer.
■ If a message about an operation is shown
● If a message about an operation of the accelerator pedal or bra ke pedal is
shown
• A warning message about an operation of the brake pedal may be shown
while the driving assist systems such as PCS (Pre-Collision System) (if
equipped) or the dynamic radar cruise control with full-speed r ange (if
equipped) is operating. If a warning message is shown, be sure to decel-
erate the vehicle or follow an instruction shown on the multi-i nformation
display.
• A warning message is shown when Brake Override System operates .
( P. 223, 604)
• A warning message is shown when Drive-Start Control or Parking Sup-
port Brake function (if equipped) operates ( P. 224, 376). Follow the
instructions on the multi-information display.
● If a message about an operation of the power switch is shown
An instruction for operation of the power switch is shown when the incorrect
procedure for starting the hybrid system is performed or the power switch is
operated incorrectly. Follow the instructions shown on the mult i-information
display to operate the power switch again.
● If a message about a shift operation is shown
To prevent the shift position from being selected incorrectly o r the vehicle
from moving unexpectedly, the shift position may be changed aut omatically
( P. 251) or shift operation may be required. In this case, chang e the shift
position following the instructions on the multi-information display.
● If a message or image about an open/close state of a part or replenishment
of a consumable is shown
Confirm the part indicated by the multi-information display or a warning light,
and then perform the coping method such as closing the open doo r or
replenishing a consumable.