2021 TOYOTA PRIUS Owners Manual (in English)

PRIUS_OM_OM47E09U_(U)
3374-5. Using the driving support systems
4
Driving
When constant speed control mode is selected, your vehicle will main-
tain a set speed without controllin g the vehicle-to-vehicle distance.
Select this mode only when vehic le-to-vehicle distance control mode
does not function correctly due to a dirty radar, etc.
With the cruise control off,
press and hold the “ON-OFF”
button for 1.5 seconds or more.
Immediately after the “ON-OFF”
button is pressed, the dynamic
radar cruise control indicator will
come on. Afterwards, it switches to
the cruise control indicator.
Switching to constant speed con-
trol mode is only possible when
operating the lever with the cruise
control off.
Accelerate or decelerate, with
accelerator pedal operation, to
the desired vehicle speed (at or
above approximately 20 mph
[30 km/h]) and push the lever
down to set the speed.
Cruise control “SET” indicator will
come on.
The vehicle speed at the moment
the lever is released becomes the
set speed.
Adjusting the speed setting: P. 333
Canceling and resuming the speed setting: P. 335
Selecting constant speed control mode
1
2

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
■Dynamic radar cruise control wi th full-speed range can be set when
● The shift position is in D.
● The desired set speed can be set when the vehicle speed is approximately
20 mph (30 km/h) or more.
(However, when the vehicle speed is set while driving at below approxi-
mately 20 mph [30 km/h], the set speed will be set to approxima tely 20 mph
[30 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-vehicl e distance
control mode, the vehicle speed may decrease below the set spee d 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 lever is pushed up.
● If the vehicle ahead starts off within 3 seconds after your veh icle stops, fol-
low-up cruising will be resumed.
■ Automatic cancelation of vehicle-to-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically cance led in the fol-
lowing situations.
● 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.
● The parking brake is operated.
● The vehicle is stopped by system control on a steep incline.
● 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. 258)
If vehicle-to-vehicle distance control mode is automatically ca nceled for any
reasons other than the above, there may be a malfunction in the system.
Contact your Toyota dealer.

PRIUS_OM_OM47E09U_(U)
3394-5. Using the driving support systems
4
Driving
■Automatic cancelation of c onstant 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 20 mph (30 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 reasons
other than the above, there may be a malfunction in the system. Contact your
Toyota dealer.
■ Brake operation
A brake operation sound may be heard and the brake pedal response may
change, but these are not malfunctions.
■ Warning messages and buzzers for d ynamic 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.( P. 294, 603)

340
PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
■When the sensor may not be correctly detect ing the vehicle ahead
In the case of the following and depending on the conditions, o perate 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 o f vehicles, the
approach warning ( P. 336) may not be activated.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving in the same lane
● Vehicles with small rear ends (trailers with no load on board, etc.)
● Motorcycles traveling in the same lane
● When water or snow thrown up by the surrounding vehicles hinders the
detecting of the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
● Preceding vehicle has an extremely high
ground clearance

PRIUS_OM_OM47E09U_(U)
3414-5. Using the driving support systems
4
Driving
■Conditions under which the vehic le-to-vehicle distance control mode
may not function correctly
In the case of the following conditions, operate the brake peda l (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 driving on a road surrounded by a structure, such as in a tunnel or on
a bridge
● While the vehicle speed is decreasing to the set speed after th e vehicle
accelerates by depressing the accelerator pedal
●
When the road curves or when the lanes
are narrow
● When steering wheel operation or your
position in the lane is unstable

342
PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
Cruise control
Use the cruise control to maintain a set speed without depressi ng the
accelerator pedal.
Use the cruise control on freeways and highways.
Indicators
Cruise control switch
Set speed
: If equipped
Summary of functions
1
2
3

PRIUS_OM_OM47E09U_(U)
3434-5. Using the driving support systems
4
Driving
Press the “ON-OFF” button to
activate the cruise control.
Cruise control indicator will come
on.
Press the button again to deacti-
vate the cruise control.
Accelerate or decelerate, with
accelerator pedal operation, to
the desired vehicle speed
(above approximately 20 mph
[30 km/h]) and push the lever
down to set the speed.
Cruise control “SET” indicator will
come on.
The vehicle speed at the moment
the lever is released becomes the
set speed.
Setting the vehicle speed
1
2

344
PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
To change the set speed, operate the lever until the desired se t 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 c ontinu-
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 20 mph
(30 km/h).
Adjusting the set speed
1
2
Canceling and resuming t he constant speed control
1
2