2010 TOYOTA PRIUS brake

228 2-4. Using other driving systems
PRIUS_U (OM47668U) U.S.A.
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control. 
Be aware of the set speed. If automatic deceleration/acceleration is not
appropriate, adjust the vehicle speed, as well as the distance between your
vehicle and vehicles ahead by applying the brakes etc.
■ Cautions regarding the driving assist systems
Observe the following precautions. 
Failure to do so may cause an accident resulting in death or serious injury.
● Assisting the driver to measure following distance 
The dynamic radar cruise control is only intended to help the driver in
determining the following distance between the driver’s own vehicle and a
designated vehicle traveling ahead. It is not a mechanism that allows care-
less or inattentive driving, and it is not a system that can assist the driver in
low-visibility conditions. It is still necessary for driver to pay close attention
to the vehicle’s surroundings.
● Assisting the driver to judge proper following distance 
The dynamic radar cruise control determines whether the following dis-
tance between the driver’s own vehicle and a designated vehicle traveling
ahead is appropriate or not. It is not capable of making any other type of
judgement. Therefore, it is absolutely necessary for the driver to remain
vigilant and to determine whether or not there is a possibility of danger in
any given situation.
● Assisting the driver to operate the vehicle 
The dynamic radar cruise control has no capability to prevent or avoid a
collision with a vehicle traveling ahead. Therefore, if there is ever any dan-
ger, the driver must take immediate and direct control of the vehicle and
act appropriately in order to ensure the safety of all involved.
■ To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON-OFF” button when not in use.

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PRIUS_U (OM47668U) U.S.A.
CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting in death or serious injury.
● In heavy traffic
● On roads with sharp bends
● On winding roads
● On slippery roads, such as those covered with rain, ice and snow
● On steep downhills, or where there are sudden changes between sharp up
and down gradients 
Vehicle speed may exceed the set speed when driving down a steep hill.
● At entrances to expressways
● When weather conditions are bad enough that they may prevent the sen-
sors from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
● When an approach warning buzzer can be heard often
■ When the sensor may not be corr ectly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles
are in front of you. 
As the sensor may not be able to correctly detect these types of vehicles,
the approach warning ( P. 227) will not be activated, and a fatal or serious
accident may result.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving
● Vehicles with small rear ends (trailers with no load on board etc.)
● Motorcycles traveling in the same lane

230 2-4. Using other driving systems
PRIUS_U (OM47668U) U.S.A.
CAUTION
■Conditions under which the vehicle -to-vehicle distance control may
not function correctly
Apply the brakes as necessary in the following conditions as the radar sen-
sor may not be able to correctly detect vehicles ahead, and a fatal or serious
accident may result:
● When water or snow thrown up by the surrounding vehicles hinders the
functioning of the sensor
● When your vehicle is pointing upwards (caused by a heavy load in the lug-
gage compartment etc.)
● When the road curves or when the lanes are narrow
● When steering wheel operation or your position in the lane is unstable
● When the vehicle ahead of you decelerates suddenly
■ Handling the radar sensor
Observe the following to ensure the cruise control system can function effec-
tively. 
Otherwise, the system may not function correctly and could result in an acci-
dent.
● Keep the sensor and front grille cover clean at all times. 
Clean the sensor and front grille cover with a soft cloth so you do not mark
or damage them.
● Do not subject the sensor or surrounding area to a strong impact . 
If the sensor moves even slightly off position, the system may malfunction.
If the sensor or surrounding area is subject to a strong impact, always
have the area inspected and adjusted by a Toyota dealer.
● Do not disassemble the sensor.
● Do not attach accessories or stickers to the sensor, grille cover or sur-
rounding area.
● Do not modify or paint the sensor and grille cover.
● Do not replace them with non-genuine parts.

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PRIUS_U (OM47668U) U.S.A.
■Temporary cancellation of the LKA system functions
If any of the following occurs, the LKA system functions will be temporarily
canceled. The functions will resume after the necessary operating conditions
have returned.
● The turn signal lever is operated.
● The steering wheel is turned as far as necessary to cause the vehicle to
change lanes.
● The brake pedal is depressed. 
The lane keeping assist function will not resume even after the brake
pedal is released because depressing the brake pedal also cancels the
dynamic radar cruise control.
● The vehicle speed deviates from the operating range of the LKA system
functions. (The buzzer will beep twice when the lane keeping assist func-
tion is being canceled.)
● When the lane lines cannot be recognized while driving. (The buzzer will
beep twice when the lane keeping assist function is being canceled.)
● Low speed or high speed wiper operation states. (The buzzer will beep
twice when the lane keeping assist function is being canceled.) 
The buzzer may not beep when the LKA system functions are canceled
because the notification of dynamic radar cruise control cancellation
takes priority over the LKA system and cancels the function.
● The no-handed driving warning activates while the lane keeping assist
function is active. (The buzzer will beep twice.)

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PRIUS_U (OM47668U) U.S.A.
Hill-start assist control
■Hill-start assist control operating conditions
The system operates in the following situations:
• The shift position is in other than “P”.
• The parking brake is not applied.
• The accelerator pedal is not depressed.
■ Hill-start assist control
● While hill-start assist control is operating, the brakes remain automati-
cally applied after the driver releases the brake pedal. The stop lights and
the high mounted stoplight turn on.
● Hill-start assist control operates for about 2 seconds after the brake pedal
is released.
● If the slip indicator does not flash and the buzzer does not sound when
the brake pedal is further depressed, slightly reduce the pressure on the
brake pedal (do not allow the vehicl e to roll backward) and then firmly
depress it again. If the system still does not operate, check that the oper-
ating conditions explained above have been met.
Hill-start assist control helps to prevent the vehicle from rolling
backwards when starting on incline or slippery slope.
To engage hill-start assist con-
trol, further depress the brake
pedal when the vehicle is
stopped completely.
A buzzer will sound once to
indicate the system is acti-
vated. The slip indicator will
also start flashing.
ITO24P109

244 2-4. Using other driving systems
PRIUS_U (OM47668U) U.S.A.
■Hill-start assist control buzzer
● When hill-start assist control is activated, the buzzer will sound once.
● In the following situations, hill-start assist control will be canceled and the
buzzer will sound twice.
• No attempt is made to drive the vehicle within approximately 2 seconds
of releasing the brake pedal.
• The “P” position switch is pressed.
• The parking brake is applied.
• The brake pedal is depressed again.
■ If the slip indicator comes on...
It may indicate a malfunction in the system. Contact your Toyota dealer.
CAUTION
■Hill-start assist control
● Do not overly rely on hill-start assist control. Hill-start assist control may
not operate effectively on extremely st eep inclines or roads covered in ice.
● Unlike the parking brake, hill-start assist control is not intended 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 for an extended
period of time, as doing so may lead to an accident.

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PRIUS_U (OM47668U) U.S.A.
Driving assist systems
To help enhance driving safety and performance, the following sys-
tems operate automatically in res ponse to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too h eavily when operating the vehicle.
■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.
■Enhanced VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning
on slippery road surfaces.
■TRAC (Traction Control)
Maintains drive power and prevents the front wheels from spinning
when starting the vehicle or accelerating on slippery roads.
■Hill-start assist control
P. 243
■ EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.
■Pre-Collision System (if equipped)
P. 249

246 2-4. Using other driving systems
PRIUS_U (OM47668U) U.S.A.
When the Enhanced VSC/TRAC is operatingIf the vehicle is in danger of slip-
ping or if the front wheels spin,
the slip indicator light flashes to
indicate that the Enhanced VSC/
TRAC have been engaged.
A buzzer (intermittent) sounds to
indicate that Enhanced VSC is
operating.
ITO24P109
■Sounds and vibrations caused by the ABS, brake assist, TRAC and
Enhanced VSC
● A sound may be heard from the engine compartment when the hybrid
system is started, just after the vehicle begins to move, if the brake pedal
is depressed forcefully or repeatedly, or 1 - 2 minutes after the hybrid
system is stopped. This sound does not indicate that a malfunction has
occurred in any of these systems.
● Any of the following conditions may occur when the above systems are
operating. 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.
■ EPS operation sound
When the steering wheel operates, a mo tor sound (whirring sound) may be
heard. 
This does not indicate a malfunction.