TOYOTA PRIUS PRIME 2021 Owners Manual (in English)

PRIUS PRIME_OM_OM47D71U_(U)
4215-5. Using the driving support systems
5
Driving
●Adjusting the set speed by the lever
To change the set speed, operate the lever until the desired set speed
is displayed.
Increases the speed
(Except when the vehicle has been
stopped by system control in vehi-
cle-to-vehicle distance control
mode)
Decreases the speed
Fine adjustment: Momentarily
move the lever in the desired
direction.
Large adjustment: Hold the lever up or down to change the speed,
and release when the desired speed is reached.
In the vehicle-to-vehicle distance control mode, the set speed will be
increased or decreased as follows:
For the U.S. mainland and Hawaii
Fine adjustment: By 1 mph (1.6 km/h)
*1 or 1 km/h (0.6 mph)*2 each time
the lever is operated
Large adjustment: Increases or decreases in 1 mph (1.6 km/h)
*1 or 1 km/h
(0.6 mph)
*2 increments for as long as the lever is held
For Canada
Fine adjustment: By 1 mph (1.6 km/h)
*1 or 1 km/h (0.6 mph)*2 each time
the lever is operated
Large adjustment: Increases or decreases in 5 mph (8 km/h)
*1 or 5 km/h
(3.1 mph)
*2 increments for as long as the lever is held
In the constant speed control mode (P. 425), the set speed will be
increased or decreased as follows:
Fine adjustment: By 1 mph (1.6 km/h)*1 or 1 km/h (0.6 mph)*2 each time
the lever is operated
Large adjustment: The speed will continue to change while the lever is
held.
*1: When the set speed is shown in “MPH”
*2: When the set speed is shown in “km/h”
Adjusting the set speed
1
2

422
PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
●Increasing the set speed by the accelerator pedal
Accelerate with accelerator pedal operation to the desired vehicle
speed.
Push the lever down.
Pressing the switch changes the
vehicle-to-vehicle distance as fol-
lows:
Long
Medium
Short
The vehicle-to-vehicle distance is
set automatically to long mode
when the power switch is turned to
ON mode.
Select a distance from the table below. Note that the distances shown
correspond to a vehicle speed of 50 mph (80 km/h). Vehicle-to-vehicle
distance increases/decreases in accordance with vehicle speed.
When the vehicle is stopped by system control, the vehicle stops at a
certain vehicle-to-vehicle distance depending on the situation.
Changing the vehicle-to-vehicle distance (vehicle-to-vehicle dis-
tance control mode)
1
2
Preceding
vehicle mark
1
2
3
Vehicle-to-vehicle distance settings (vehicle-to-vehicle distance
control mode)
Distance optionsVehicle-to-vehicle distance
LongApproximately 160 ft. (50 m)
MediumApproximately 130 ft. (40 m)
ShortApproximately 100 ft. (30 m)

PRIUS PRIME_OM_OM47D71U_(U)
4235-5. Using the driving support systems
5
Driving
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.
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

424
PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
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 PRIME_OM_OM47D71U_(U)
4255-5. Using the driving support systems
5
Driving
When constant speed control mode is selected, your vehicle will main-
tain a set speed without controlling the vehicle-to-vehicle distance.
Select this mode only when vehicle-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. 421
Canceling and resuming the speed setting: P. 423
Selecting constant speed control mode
1
2

426
PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
■Dynamic radar cruise control with 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 approximately 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-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 lever is pushed up.
●If the vehicle ahead starts off within 3 seconds after your vehicle 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 canceled 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.
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460044004f004f005c00030056005a004c00570046004b0003[to P. (P. 348
If vehicle-to-vehicle distance control mode is automatically canceled for any
reasons other than the above, there may be a malfunction in the system.
Contact your Toyota dealer.

PRIUS PRIME_OM_OM47D71U_(U)
4275-5. Using the driving support systems
5
Driving
■Automatic cancelation of constant 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 dynamic 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. 382, 684)

428
PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
■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. 424) 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 PRIME_OM_OM47D71U_(U)
4295-5. Using the driving support systems
5
Driving
■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 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 the 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

430
PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
Driving mode select switch
Repeatedly press the switch until the system changes to the intended
driving mode.
Each time the switch is pressed, the driving mode changes in the following
order and the “ECO MODE” and “PWR MODE” indicators turn on or off
accordingly.
In response to driving conditions, one of 3 driving modes can be
selected.
Driving modes