brake TOYOTA PRIUS PLUS 2012 Workshop Manual

305 2-4. Using other driving systems
2
When driving
PRIUS +_OM_OM47821E_(EE)
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 vehicle to roll backward) and then firmly
depress it again. If the system still does not operate, check if the operat-
ing conditions explained above have been met.
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.
• Push the P position switch.
• The parking brake is applied.
• The brake pedal is depressed again.
• The brake pedal has been depressed for more than approximately 3
minutes.
If the slip indicator light comes on
It may indicate a malfunction in the system. Contact any authorized Toyota
dealer or repairer, or another duly qualified and equipped professional.

306 2-4. Using other driving systems
PRIUS +_OM_OM47821E_(EE)
CAUTION
Hill-start assist control
Do not overly rely on the hill-start assist control. Hill-start assist control
may not operate effectively on extremely steep 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.

307
2-4. Using other driving systems
2
When driving
PRIUS +_OM_OM47821E_(EE)
PCS (Pre-Crash Safety System)
: If equipped
When the radar sensor detects possibility of a frontal collision, the
pre-crash safety systems such as the brakes and seat belts are auto-
matically engaged to lessen impact to occupants as well as vehicle
damage.
Pre-crash seat belts (front seat belts only)
If the pre-crash sensor detects that a collision is unavoidable, the pre-
crash safety system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or
loses control of the vehicle. (P. 124)
However, when the VSC system is disabled, the system will not oper-
ate in the event of skidding.
Pre-crash brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.
Pre-crash braking
When there is a high possibility of a frontal collision, the system warns
the driver using a warning light, warning display and buzzer. If the sys-
tem determines that a collision is unavoidable, the brakes are automat-
ically applied to reduce the collision speed. Pre-crash braking can be
disabled using the pre-crash braking off switch.

309 2-4. Using other driving systems
2
When driving
PRIUS +_OM_OM47821E_(EE)
The pre-crash safety system is operational when
Pre-crash seat belts (operating conditions A):
• Vehicle speed is greater than about 30 km/h (19 mph).
• The system detects sudden braking or skidding.
• The front occupants are wearing a seat belt.
Pre-crash seat belts (operating conditions B):
• Vehicle speed is greater than about 5 km/h (4 mph).
• The speed at which your vehicle is approaching the obstacle or the
vehicle running ahead of you is greater than about 30 km/h (19 mph).
• The front occupants are wearing a seat belt.
Pre-crash brake assist:
• Vehicle speed is greater than about 30 km/h (19 mph).
• The speed at which your vehicle is approaching the obstacle or the
vehicle running ahead of you is greater than about 30 km/h (19 mph).
• The brake pedal is depressed.
Pre-crash braking:
• Vehicle speed is greater than about 15 km/h (10 mph).
• The speed at which your vehicle is approaching the obstacle or the
vehicle running ahead of you is greater than about 15 km/h (10 mph).
• The pre-crash braking off switch is not pressed.

310 2-4. Using other driving systems
PRIUS +_OM_OM47821E_(EE)
Conditions that may trigger the system even if there is no possibility of
a collision
When there is an object by the roadside at the entrance to a curve
When passing an oncoming vehicle on a curve
When driving over a narrow iron bridge
When there is a metal object on the road surface
When driving on an uneven road surface (nose up, nose down)
When passing an oncoming vehicle on a left-turn (left-hand drive vehi-
cles) or right-turn (right-hand drive vehicles)
When your vehicle rapidly closes on the vehicle in front
When a grade separation/interchange, sign, billboard, or other structure
appears to be directly in the vehicle’s line of travel
When the steep angle of the road causes a metal object located beneath
the road surface to be seen ahead of the vehicle
When an extreme change in vehicle height occurs
When the axis of the radar is out of adjustment
When passing through certain toll gates
When passing through an overpass
When the system is activated in the situations described above, there is also
a possibility that the seat belts will retract quickly and the brakes will be
applied with a force greater than normal. When the seat belt is locked in the
retracted position, stop the vehicle in a safe place, release the seat belt and
refasten it.
Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may
also be occasions when the sensor cannot detect pedestrians, animals,
bicycles, motorcycles, trees, or snowdrifts.

314 2-4. Using other driving systems
PRIUS +_OM_OM47821E_(EE)
CAUTION
Limitations of the pre-crash safety system
Do not overly rely on the pre-crash safety system. Always drive safely, taking
care to observe your surroundings and checking for any obstacles or other
road hazards.
Failure to do so may cause an accident resulting in death or serious injury.
Cautions regarding the assist contents of the system
By means of alarms and brake control, the pre-crash safety system is
intended to assist the driver in avoiding collisions through the process of
LOOK-JUDGE-ACT. There are limits to the degree of assistance the system
can provide, so please keep in mind the following important points.
Assisting the driver in watching the road
The pre-crash safety system is only able to detect obstacles directly in
front of the vehicle, and only within a limited range. It is not a mechanism
that allows careless or inattentive driving, and it is not a system that can
assist the driver in low-visibility conditions. It is still necessary for the driver
to pay close attention to the vehicle’s surroundings.
Assisting the driver in making correct judgement
When attempting to estimate the possibility of a collision, the only data
available to the pre-crash safety system is that from obstacles it has
detected directly in front of the vehicle. Therefore, it is absolutely neces-
sary for the driver to remain vigilant and to determine whether or not there
is a possibility of collision in any given situation.
Assisting the driver in taking action
The pre-crash safety system’s braking assist feature is designed to help
reduce the severity of a collision, and so only acts when the system has
judged that a collision is unavoidable. This system by itself is not capable
of automatically avoiding a collision or bringing the vehicle to a stop safely.
For this reason, when encountering a dangerous situation the driver must
take direct and immediate action in order to ensure the safety of all
involved.

315 2-4. Using other driving systems
2
When driving
PRIUS +_OM_OM47821E_(EE)
CAUTION
When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary in any of the following situations.
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.)
Vehicles that cut in suddenly
Vehicles with small rear ends (trailers with no load on board etc.)
Motorcycles traveling in the same lane
Handling the radar sensor
Observe the following to ensure the pre-crash safety system can function
effectively:
Keep the sensor and grille cover clean at all times.
Clean the sensor and 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 become
inaccurate or malfunction. If the sensor or surrounding area is subject to a
strong impact, always have the area inspected and adjusted by any autho-
rized Toyota dealer or repairer, or another duly qualified and equipped pro-
fessional.
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.

317 2-5. Driving information
2
When driving
PRIUS +_OM_OM47821E_(EE)
CAUTION
Things that must not be carried in the luggage compartment
The following things may cause a fire if loaded in the luggage compartment:
Receptacles containing gasoline
Aerosol cans
Storage precautions
Observe the following precautions.
Failure to do so may result in death or serious injury.
Stow cargo and luggage in the luggage compartment whenever possible.
Do not stack cargo and luggage in the luggage compartment higher than
the seatbacks.
Such items may be thrown about and possibly injure people in the vehicle
in the event of sudden braking or in an accident.
Do not place cargo or luggage in or on the following locations as the item
may get under the brake or accelerator pedal and prevent the pedals from
being depressed properly, block the driver’s vision, or hit the driver or pas-
sengers, causing an accident:
• At the feet of the driver
• On the front passenger or rear seats (when stacking items)
• On the luggage cover
• On the instrument panel
• On the dashboard

320 2-5. Driving information
PRIUS +_OM_OM47821E_(EE)
Before driving the vehicle
Perform the following according to the driving conditions:
Do not try to forcibly open a window or move a wiper that is
frozen. Pour warm water over the frozen area to melt the ice.
Wipe away the water immediately to prevent it from freezing.
To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents
in front of the windshield.
Remove any ice that has accumulated on the vehicle chassis.
Periodically check for and remove any excess ice or snow
that may have accumulated in the wheel well or on the
brakes.
When driving the vehicle
Accelerate the vehicle slowly and drive at a reduced speed suit-
able to the road conditions.
When parking the vehicle
Park the vehicle and shift the shift position to P and block the
wheel under the vehicle without setting the parking brake. The
parking brake may freeze up, preventing it from being released.
If necessary, block the wheels to prevent inadvertent sliding or
creeping.

392 4-2. Maintenance
PRIUS +_OM_OM47821E_(EE)
Flat-looking tires, excessive tire squeal when cornering, uneven tire wear
Vehicle pulls to one side when driving straight on a level road
Strange noises related to suspension movement
Loss of brake effectiveness, spongy feeling brake pedal, pedal almost
touches the floor, vehicle pulls to one side when braking
Engine coolant temperature continually higher than normal
If you notice any of these clues, take your vehicle to any authorized Toyota
dealer or repairer, or another duly qualified and equipped professional as
soon as possible. Your vehicle may need adjustment or repair.
CAUTION
If your vehicle is not properly maintained
Improper maintenance could result in serious damage to the vehicle and
possible serious injury or death.
Handling of the 12-volt battery
12-volt battery posts, terminals and related accessories contain lead and
lead compounds which are known to cause brain damage. Wash your hands
after handling. (P. 413)