
PRIUS v_OM_OM47B23U_(U)
2274-5. Using the driving support systems
4
Driving
WARNING
■Conditions under which the vehicle-to-vehicle distance control may
not function correctly
Apply the brakes (or accelerator pedal) as necessary in the following condi-
tions as the radar sensor may not be able to correctly detect vehicles
ahead, and a fatal or serious accident may result:
● When the vehicle ahead of you decelerates suddenly
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
●When the road curves or when the
lanes are narrow
● When steering wheel operation or your
position in the lane is unstable
Accelerate
Accelerate
Decelerate

230
PRIUS v_OM_OM47B23U_(U)
4-5. Using the driving support systems
When the system judges that the vehicle is deviating from the current
traffic lane, an alert buzzer sounds and it prompts cautions from the
display screen of the multi-information display.
When the alert buzzer sounds, please check the surrounding road situa-
tion and return near the center of the white (yellow) lane markers by safely
operating the steering wheel.
Press the LDA switch to activate
the LDA.
LDA indicator will come on and
lane lines will be displayed on the
multi-information display.
Press the switch again to deacti-
vate the LDA.
The LDA will remain on or off even
if the power switch is turned off.
Lane departure alert function
Alert buzzer
Turning the LDA on

PRIUS v_OM_OM47B23U_(U)
2354-5. Using the driving support systems
4
Driving
WARNING
■Before using the LDA
Do not over rely on the LDA. The LDA does not drive the vehicle automati-
cally, nor does it reduce the amount of care you need to take. As such, the
driver must always assume full responsibility for understanding his/her sur-
roundings, for operating the steering wheel to correct the driving line, and
for driving safely. Also, take occasional rests from fatigue due to driving over
long periods of time, etc.
Inappropriate or negligent driving could lead to an unexpected accident.
■ To avoid operating the LDA by mistake
Switch the LDA off using the LDA switch when not in use. ( P. 230)
■ Situations unsuitable for LDA
Do not use the LDA in any of the following situations.
Otherwise, the system may not function correctly and could result in an
accident.
●When driving with tire chains, a spare tire, or similar equipment
● When there are objects or structures along the roadside that might be mis-
interpreted as lane markers (such as guardrails, a curb, reflector posts,
etc.)
● When driving on snowy roads
● When pavement lane markers are difficult to see due to rain, snow, fog,
sand, dirt, etc.
● When there are visible lines on the pavement from road repairs, or if the
remains of old lane markers are still visible on the road
● When driving through construction areas

PRIUS v_OM_OM47B23U_(U)
2454-5. Using the driving support systems
4
Driving
WARNING
■When using the rear view monitor system
The rear view monitor system is a supplemental device intended to assist
the driver when backing up. When backing up, be sure to visually check all
around the vehicle both directly and using the mirrors before proceeding.
Observe the following precautions to avoid an accident that could result in
death or serious injuries.
● Never depend on the rear view monitor system entirely when backing up.
The image and the position of the guide lines displayed on the screen may
differ from the actual state.
Use caution, just as you would when backing up any vehicle.
● Be sure to back up slowly, depressing the brake pedal to control vehicle
speed.
● The instructions given are only guide lines.
When and how much to turn the steering wheel will vary according to traf-
fic conditions, road surface conditions, vehicle condition, etc. when park-
ing. It is necessary to be fully aware of this before using the rear view
monitor system.
● When parking, be sure to check that the parking space will accommodate
your vehicle before maneuvering into it.
● Do not use the rear view monitor system in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or emergency tires
• When the back door is not closed completely
• On roads that are not flat or straight, such as curves or slopes
● In low temperatures, the screen may darken or the image may become
faint. The image could distort when the vehicle is moving, or you may
become unable to see the image on the screen. Be sure to visually check
all around the vehicle both directly and using the mirrors before proceed-
ing.
● If the tire sizes are changed, the position of the fixed guide lines displayed
on the screen may change.
● The camera uses a special lens. The distances between objects and
pedestrians that appear in the image displayed on the screen will differ
from the actual distances. ( P. 240)

248
PRIUS v_OM_OM47B23U_(U)
4-5. Using the driving support systems
Driving assist systems
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corre-
sponding to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly,
or if the brakes are applied while driving on a slippery road surface
◆Brake assist
Generates an increased level of braking force after the brake pedal
is depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or
turning on slippery road surfaces
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery roads
◆EPS (Electric Power Steering)
Employs an electric motor to redu ce the amount of effort needed to
turn the steering wheel
◆Enhanced VSC (Enhanced Ve hicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional st ability when swerving on slippery
road surfaces by controllin g steering performance.
To help enhance driving safety and performance, the following
systems operate automatically in response to various driving
situations. Be aware, however, that these systems are supple-
mentary and should not be relied upon too heavily when operat-
ing the vehicle.

PRIUS v_OM_OM47B23U_(U)
2514-5. Using the driving support systems
4
Driving
■Turning off both TRAC/VSC systems
To turn the TRAC/VSC systems off, press and hold for more than 3 sec-
onds while the vehicle is stopped.
Vehicles without multi-information display
The “TRAC OFF” and VSC OFF in dicator lights will come on.
Vehicles with multi-information display
The VSC OFF indicator light will come on and the message will be shown on
the multi-information display.
*
Press again to turn the systems back on.
*: On vehicles with pre-collision system, pre-collision brake assist and pre- collision braking will also be disabled. The PCS warning light will come on
and the message will be shown on the multi-information display. ( P. 493)
■ When the “TRAC OFF” indicator co mes on/message is displayed on the
multi-information display showing that TRAC has been disabled even if
the VSC OFF switch has not been pressed
TRAC cannot be operated. Contact your Toyota dealer.
■ Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and
hill-start assist control systems
Any of the following conditions may occur when the above systems are oper-
ating. None of these indicates that a malfunction has occurred.
● Vibrations may be felt through the vehicle body and steering.
● A motor sound may be heard after the vehicle comes to a stop.
● The brake pedal may pulsate slightly after the ABS is activated.
● The brake pedal may move down slightly after the ABS is activated.
■ 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 brake pedal
is operated.
● Motor sound of the brake system heard from the front part of the vehicle
when the driver’s door is opened.
● Operating sound heard from the engine compartment when 1 or 2 minutes
passed after the stop of the hybrid system.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.

252
PRIUS v_OM_OM47B23U_(U)
4-5. Using the driving support systems
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from
overheating when there is frequent steering input over an extended period of
time. The steering wheel may feel heavy as a result. Should this occur, refrain
from excessive steering input or stop the vehicle and turn the hybrid system
off. The EPS system should return to normal within 10 minutes.
■ Automatic reactivation of TRAC system
After turning the TRAC system off, the system will be automatically re-
enabled in the following situations:
●When the power switch is turned off
● The TRAC will turn on when vehicle speed increases
■ Electric power steering system warning light (warning buzzer)
P. 493
■ Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will
operate:
●The shift position is in a position other than P or N (when starting off forward/
backward on an upward incline).
● The vehicle is stopped.
● The accelerator pedal is not depressed.
● The parking brake is not engaged.
■ 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.
● Approximately 2 seconds elapse after the brake pedal is released.

PRIUS v_OM_OM47B23U_(U)
2594-5. Using the driving support systems
4
Driving
■Situations in which the pre-collis ion system does not function properly
The system may not function effectively in situations such as the following:
● On roads with sharp bends or uneven surfaces
● If a vehicle suddenly moves in front of your vehicle, such as at an intersec-
tion
● If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
● In inclement weather such as heavy rain, fog, snow or sand storms
● When your vehicle is skidding with the VSC system off
● When an extreme change in vehicle height occurs
● When the radar sensor moves off position due to its surrounding area being
subjected to a strong impact
● Due to greatly turning the steering wheel when an obstacle suddenly
appears ahead
● When only part of your vehicle’s front end collides with or contacts, a vehicle
or object in a frontal collision
■ Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc. that results in
the sensors being unable to detect obstacles, the pre-collision system will be
automatically disabled. In this case, the system will not activate even if there
is a collision possibility.
■ When there is a malfunction in the system, or if the system is tempo-
rarily unusable
The PCS warning light flashes and a warning message is shown on the multi-
information display. If a warning message is shown on the multi-information
display, read the message and follow the instructions. ( P. 492, 506)
■ Certification for th e pre-collision system
For vehicles sold in the U.S.A.
For vehicles sold in Canada