brake TOYOTA PRIUS 2018 (in English) Service Manual

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4-5. Using the driving support systems
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-
vehicle distance can also be set by operating the vehicle-to-vehicle dis-
tance switch.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed
appears
When a vehicle is detected running ahead of you, the system automatically
decelerates your vehicle. When a greater reduction in vehicle speed is
necessary, the system applies the brakes (the stop lights will come on at
this time). The system will respond to changes in the speed of the vehicle
ahead in order to maintain the vehicle-to-vehicle distance set by the driver.
Approach warning warns you when the system cannot decelerate suffi-
ciently to prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehicle will also stop (vehicle is
stopped by system control). After the vehicle ahead starts off, pushing the
cruise control lever up or depressing the accelerator pedal will resume fol-
low-up cruising.
Example of acceleration
When there are no longer any preceding vehicles driving slower
than the set speed
The system accelerates until the set speed is reached. The system then
returns to constant speed cruising.
1
2
3

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After the vehicle ahead of you
starts off, push the lever up.
Your vehicle will also resume fol-
low-up cruising if the accelerator
pedal is depressed after the vehi-
cle ahead of you starts off.
Pulling the lever toward you
cancels the speed control.
The speed control is also canceled
when the brake pedal is
depressed.
(When the vehicle has been
stopped by system control,
depressing the brake pedal does
not cancel the setting.)
Pushing the lever up resumes the cruise control and returns vehicle
speed to the set speed.
However, when a vehicle ahead is not detected, cruise control does not
resume when the vehicle speed is approximately 25 mph (40 km/h) or less.
Resuming follow-up cruising when the vehicle has been stopped
by system control (vehicle-to-vehicle distance control mode)
Canceling and resuming the speed control
1
2

PRIUS_OM_OM47B89U_(U)
3134-5. Using the driving support systems
4
Driving
When your vehicle is too close to
a vehicle ahead, and sufficient
automatic deceleration via the
cruise control is not possible, the
display will flash and the buzzer
will sound to alert the driver. An
example of this would be if
another driver cuts in front of you
while you are following a vehicle.
Depress the brake pedal to
ensure an appropriate vehicle-to-
vehicle distance.
■Warnings may not occur when
In the following instances, warnings may not occur even when the
vehicle-to-vehicle distance is small.
●When the speed of the preceding vehicle matches or exceeds
your vehicle speed
● When the preceding vehicle is traveling at an extremely slow
speed
● Immediately after the cruise control speed was set
● When depressing the accelerator pedal
Approach warning (vehicle-to-vehicle distance control mode)

PRIUS_OM_OM47B89U_(U)
3154-5. Using the driving support systems
4
Driving
■Dynamic radar cruise control with full-speed range can be set when
● The shift position is in D.
● Vehicle speed is at or above approximately 30 mph (50 km/h).
However, when a preceding vehicle is detected, the dynamic radar cruise
control with full-speed range can be set even if the vehicle speed is below
approximately 30 mph (50 km/h).
■ Accelerating after setting the vehicle speed
The vehicle can accelerate by operating the accelerator pedal. After acceler-
ating, the set speed resumes. However, during vehicle-to-vehicle distance
control mode, the vehicle speed may decrease below the set speed in order
to maintain the distance to the preceding vehicle.
■ When the vehicle stops while follow-up cruising
●Pushing the lever up while the vehicle ahead stops will resume follow-up
cruising if the vehicle ahead starts off within approximately 3 seconds after
the switch is pressed.
● If the vehicle ahead starts off within 3 seconds after your vehicle stops, fol-
low-up cruising will be resumed.
■ Automatic cancelation of vehicle-t o-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically canceled in the fol-
lowing situations.
● Actual vehicle speed falls at or below approximately 25 mph (40 km/h) when
there are no vehicles ahead.
● The preceding vehicle leaves the lane when your vehicle is following at a
vehicle speed at or below approximately 25 mph (40 km/h). Otherwise, the
sensor can not properly detect the vehicle.
● VSC is activated.
● TRAC is activated for a period of time.
● When the VSC or TRAC system is turned off.
● The sensor cannot detect correctly because it is covered in some way.
● Pre-collision braking is activated.
● Intelligent Clearance Sonar is operated. (if equipped)
● The parking brake is operated.
● The vehicle is stopped by system control on a steep incline.

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●The following are detected when the vehicle has been stopped by system
control:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes.
In this situation, the shift position may automatically switch to P. ( →P. 243)
If vehicle-to-vehicle distance control mode is automatically canceled for any
other reason, there may be a malfunction in the system. Contact your Toyota
dealer.
■ Automatic cancelation of co nstant speed control mode
Constant speed control mode is automatically canceled in the following situa-
tions:
● Actual vehicle speed is more than approximately 10 mph (16 km/h) below
the set vehicle speed.
● Actual vehicle speed falls below approximately 25 mph (40 km/h).
● VSC is activated.
● TRAC is activated for a period of time.
● When the VSC or TRAC system is turned off.
● Pre-collision braking is activated.
If constant speed control mode is automatically canceled for any other rea-
son, there may be a malfunction in the system. Contact your Toyota dealer.
■ Warning messages and buzzers for dy namic radar cruise control with
full-speed range
Warning messages and buzzers are used to indicate a system malfunction or
to inform the driver of the need for caution while driving. If a warning message
is shown on the multi-information display, read the message and follow the
instructions.
■ When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the
brake pedal when deceleration of the system is insufficient or operate the
accelerator pedal when acceleration is required.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning ( →P. 313) may not be activated.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving in the same lane

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■Conditions under which the vehicle -to-vehicle distance control mode
may not function correctly
In the case of the following conditions, operate the brake pedal (or accelera-
tor pedal, depending on the situation) as necessary.
As the sensor may not be able to correctly detect vehicles ahead, the system
may not operate properly.
● When the vehicle ahead of you decelerates suddenly
●
When the road curves or when the lanes
are narrow
● When steering wheel operation or your
position in the lane is unstable

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3214-5. Using the driving support systems
4
Driving
To change the set speed, operate the lever until the desired set speed
is obtained.
Increases the speed
Decreases the speed
Fine adjustment: Momentarily
move the lever in the desired direc-
tion.
Large adjustment: Hold the lever in
the desired direction.
The set speed will be increased or decreased as follows:
Fine adjustment: By approximately 1 mph (1.6 km/h) or 1 km/h (0.6 mph)
each time the lever is operated.
Large adjustment: The set speed can be increased or decreased continu-
ally until the lever is released.
Pulling the lever toward you
cancels the c onstant speed
control.
The speed setting is also canceled
when the brake pedal is
depressed.
Pushing the lever up resumes
the constant speed control.
However, resuming is available
when the vehicle speed is more
than approximately 25 mph
(40 km/h).
Adjusting the set speed
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2
Canceling and resuming the constant speed control
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2

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WARNING
■When using Intuitive parking assist
Observe the following precautions to avoid an unexpected accident.
● Do not exceed the speed limit of 6 mph (10 km/h).
● The sensors’ detection areas and reaction times are limited. When moving
forward or reversing, check the areas surrounding the vehicle (especially
the sides of the vehicle) for safety, and drive slowly, using the brake to
control the vehicle’s speed.
● Do not install accessories within the sensors’ detection areas.

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3474-5. Using the driving support systems
4
Driving
WARNING
■Sensors
Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where
this may occur are listed below.
● There is dirt, snow or ice on the sensor. (Wiping the sensors will resolve
this problem.)
● The sensor is frozen. (Thawing the area will resolve this problem.)
In especially cold weather, if a sensor is frozen, the screen may show an
abnormal display, or obstacles may not be detected.
● The sensor is covered in any way.
● In harsh sunlight or intense cold weather
● On an extremely bumpy road, on an incline, on gravel, or on grass
● The vicinity of the vehicle is noisy due to vehicle horns, motorcycle
engines, air brakes of large vehicles , or other loud noises producing ultra-
sonic waves.
● The sensor is splashed with water or drenched with heavy rain.
● The sensor is drenched with water on a flooded road.
● The vehicle is leaning considerably to one side.
● The vehicle is equipped with a fender pole or wireless antenna.
● The vehicle is approaching a tall or curved curb.
● The detection range is reduced due to an object such as a sign.
● The area directly under the bumpers is not detected.
● If obstacles draw too close to the sensor.
● The bumper or sensor receives a strong impact.
● A non-genuine Toyota suspension (lowered suspension etc.) is installed.
● There is another vehicle equipped with parking assist sensors in the vicin-
ity.
● Towing eyelets are installed.
● A backlit license plate is installed.
In addition to the examples above, depending on the shape and condition of
obstacles, detection may not be possible, or the detection range may be
shortened.

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4-5. Using the driving support systems
Intelligent Clearance Sonar∗
The system operates in the following situations when an obstacle is
detected in the traveling direction of the vehicle.
◆The vehicle is driven at low speeds and the brake pedal is not
depressed, or is depressed too late
◆The accelerator pedal is depressed too far
∗: If equipped
When a collision may occur with an obstacle while parking or
traveling at low speeds, when the vehicle suddenly moves for-
ward due to mistaken accelerator pedal operation, or when the
vehicle moves due to the wrong shift position being selected,
the sensors detect obstacles to the front or rear in the traveling
direction of the vehicle, and the system operates to lessen
impact with obstacles such as walls, and reduce resulting dam-
age.
Examples of system operation