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PRIUS_OM_OM47A29U_(U)
3034-5. Using the driving support systems
4
Driving
This mode employs a radar sensor  to detect the presence of vehicles
up to approximately 400 ft. (120 m) ahead, determines the current
vehicle-to-vehicle following distance, and operates to maintain a suit-
able following distance from the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long
downhill slopes.
Driving in vehicle-to-vehi cle distance control mode 
         
        
        
     
        
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When constant speed cont rol mode is selected, your vehicle will main-
tain a set speed without  controlling the vehicle-to-vehicle distance.
Select this mode only when vehicl e-to-vehicle distance control mode
does not function correctly  due to a dirty radar sensor.
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 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
(above approximately 30 mph
[50 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. 306
Canceling and resuming the speed setting:  P. 308
Selecting constant speed control mode
1
2 
         
        
        
     
        
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PRIUS_OM_OM47A29U_(U)
3114-5. 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 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 at or
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.
■ Automatic cancelation of vehicle -to-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically canceled in the fol-
lowing situations.
● Actual vehicle speed falls 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 below approximately 25 m ph (40 km/h). Otherwise, the sen-
sor 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 by pressing the VSC OFF
switch.
● The sensor cannot detect correctly because it is covered in some way.
● Pre-collision braking is activated.
● The parking brake is operated.
● Intelligent Clearance Sonar is operated. (if equipped)
● 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. 237)
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. 
         
        
        
     
        
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■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 by pressing the VSC OFF
switch.
● Pre-collision braking is activated.
● Intelligent Clearance Sonar is operated. (if equipped)
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.
■ 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. 309) will not be activated, which may lead to an acci-
dent resulting in death or serious injury.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving in the same lane 
         
        
        
     
        
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PRIUS_OM_OM47A29U_(U)
3134-5. Using the driving support systems
4
Driving
●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 
         
        
        
     
        
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■Conditions under which the vehicle -to-vehicle distance control mode
may not function correctly
Operate the brake pedal (or accelerator pedal operation depending on the sit-
uation) as necessary in the following conditions as the radar sensor may not
be able to correctly detect vehicles ahead, which may lead to an accident
resulting in death or serious injury.
● 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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4-5. Using the driving support systems
BSM (Blind Spot Monitor)
The Blind Spot Monitor is a  system that has 2 functions;
● The Blind Spot Monitor function 
Assists the driver in making the decision when changing lanes
● The Rear Cross Traffic Alert function (if equipped) 
Assists the driver when backing up
These functions use same sensors.
Outside rear view mirror indicators
Blind Spot Monitor function: 
When a vehicle is detected in the blind spot, the outside rear view mirror
indicator comes on while the turn signal lever is not operated and the out-
side rear view mirror indicator flashes while the turn signal lever is oper-
ated.
Rear Cross Traffic Alert function: 
When a vehicle approaching from the right  or left rear of the vehicle is
detected, the outside rear view mirror indicators flash.
: If equipped
Summary of the Blind Spot Monitor
1 
         
        
        
     
        
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4-5. Using the driving support systems
■The BSM outside rear view  mirror indicators visibility
When under strong sunlight, the outside rear view mirror indicator may be dif-
ficult to see.
■ Rear Cross Traffic Alert bu zzer hearing (if equipped)
Rear Cross Traffic Alert function may be difficult to hear over loud noises
such as high audio volume.
■ When “Blind Spot Moni tor Unavailable” is shown on the multi-informa-
tion display
The sensor voltage has become abnormal, water, snow mud, etc., may be
built up in the vicinity of the sensor area of bumper ( P. 326). Removing the
water, snow, mud, etc., from the vicinity of the sensor area bumper should
return it to normal. Also, the sensor may not function normally when used in
extremely hot or cold weather.