TOYOTA PRIUS 2020 Owners Manual (in English)

PRIUS_OM_OM47D44U_(U)
3114-5. Using the driving support systems
4
Driving
■Temporary cancellation of functions
When the operation conditions are no longer met, a function may be tempo-
rarily canceled. However, when the operation conditions are met again, oper-
ation of the function is automatically restored. ( P. 310)
■ Steering control function
Depending on the vehicle speed, lane departure situation, road conditions,
etc., the driver may not feel the function is operating or the function may not
operate at all.
■ Lane departure alert function
The warning buzzer may be difficult to hear due to external noi se, audio play-
back, etc.
■ Hands off steering wheel warning
If the driver continues to keep their hands off of the steering wheel, a buzzer
sounds and a warning message and the symbol shown in the illust ration are
displayed on the multi-information display. This warning also o perates in the
same way when the driver continuously operates the steering whe el only a
small amount. Always keep your hands on the steering wheel when using this
system, regardless of warnings.
Depending on the vehicle and road conditions, the warning may n ot operate.
■ Vehicle sway warning function
■ White (yellow) lines are only on one side of road
The LDA system will not operate for the side on which white (yellow) lines
could not be recognized. When the system determines that the
driver has removed their hands from the
steering wheel while the steering control
function is operating, a warning message
urging the driver to hold the steering
wheel and the symbol shown in the illus-
tration are displayed on the multi-informa-
tion display.
When the system determines that the
vehicle is swaying while the vehicle sway
warning function is operating, a buzzer
sounds and a warning message urging
the driver to rest and the symbol shown in
the illustration are simultaneously dis-
played on the multi-information display.
Depending on the vehicle and road condi-
tions, the warning may not operate.

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4-5. Using the driving support systems
■Conditions in which functions may not operate properly
In the following situations, the camera sensor may not detect w hite (yellow)
lines and various functions may not operate normally.
● There are shadows on the road that run parallel with, or cover, the white
(yellow) lines.
● The vehicle is driven in an area without white (yellow) lines, such as in front
of a tollgate or checkpoint, or at an intersection, etc.
● The white (yellow) lines are cracked, “Botts’ dots”, “Raised pa vement
marker” or stones are present.
● The white (yellow) lines cannot be seen or are difficult to see due to sand,
etc.
● The vehicle is driven on a road surface that is wet due to rain , puddles, etc.
● The traffic lines are yellow (which may be more difficult to re cognize than
lines that are white).
● The white (yellow) lines cross over a curb, etc.
● The vehicle is driven on a bright surface, such as concrete.
● The vehicle is driven on a surface that is bright due to reflec ted light, etc.
● The vehicle is driven in an area where the brightness changes s uddenly,
such as at the entrances and exits of tunnels, etc.
● Light from the headlights of an oncoming vehicle, the sun, etc. enters the
camera.
● The vehicle is driven where the road diverges, merges, etc.
● The vehicle is driven on a slope.
● The vehicle is driven on a road which tilts left or right, or a winding road.
● The vehicle is driven on an unpaved or rough road.
● The vehicle is driven around a sharp curve.
● The traffic lane is excessively narrow or wide.
● The vehicle is extremely tilted due to carrying heavy luggage or having
improper tire pressure.
● The distance to the preceding vehicle is extremely short.
● The vehicle is moving up and down a large amount due to road co nditions
during driving (poor roads or road seams).
● The headlight lenses are dirty and emit a faint amount of light at night, or the
beam axis has deviated.
● The vehicle is struck by a crosswind.
● The vehicle has just changed lanes or crossed an intersection.
● Snow tires, etc. are equipped.

PRIUS_OM_OM47D44U_(U)
3134-5. Using the driving support systems
4
Driving
■Warning message
If the following warning message is displayed on the multi-information dis-
play, follow the appropriate troubleshooting procedure.
If a different warning message is displayed, follow the instructions displayed
on the screen.
Warning messageDetails/Actions
“Lane Departure Alert
Malfunction
Visit Your Dealer”The system may not be operating
properly.
 Have the vehicle inspected at your
Toyota dealer.
“Front Camera
Unavailable
See Owner’s Manual”
Dirt, rain, condensation, ice, snow,
etc. are present on the windshield in
front of the camera sensor.
 Turn the LDA system off, remove
any dirt, rain, condensation, ice,
snow, etc. from the windshield, and
then turn the LDA system back on.
“Front Camera
Unavailable”
The operation conditions of the cam-
era sensor (temperature, etc.) are not
met.
 When the operation conditions of
the camera sensor (temperature,
etc.) are met, the LDA system will
become available. Turn the LDA
system off, wait for a little while,
and then turn the LDA system back
on.
“Lane Departure Alert
Unavailable”
The LDA system is temporarily can-
celed due to a malfunction in a sensor
other than the camera sensor.
Turn the LDA system off and follow
the appropriate troubleshooting
procedures for the warning mes-
sage. Afterward, drive the vehicle
for a short time, and then turn the
LDA system back on.
“Lane Departure Alert
System is Unavailable
Below Approx.32 MPH.”The LDA system cannot be used as
the vehicle speed is less than approxi-
mately 32 mph (50 km/h).
 Drive the vehicle at approximately
32 mph (50 km/h) or more.

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4-5. Using the driving support systems
■Customization
The following settings can be changed.
For how to change settings, refer to P. 149.
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Steering control functionTurn steering wheel assistance on and off
Vehicle sway warning functionTurn function on and off
Adjust alert sensitivity

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PRIUS_OM_OM47D44U_(U)
4-5. Using the driving support systems
4
Driving
Dynamic radar cruise controlwith full-speed
range

In vehicle-to-vehicle distance control mode, the vehicle automa tically
accelerates, decelerates and st ops to match the speed changes o f the
preceding vehicle even if the acc elerator pedal is not depressed. In
constant speed control mode, t he vehicle runs at a fixed speed.
Use the dynamic radar cruise control with full-speed range on f ree-
ways and highways.
● Vehicle-to-vehicle distance control mode ( P. 319)
● Constant speed c ontrol mode (P. 326)
Vehicle-to-vehicle distance
switch
Indicators
Display
Set speed
Cruise control switch
: If equipped
Summary of functions
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4-5. Using the driving support systems
WARNING
■Before using dynamic radar cruise control with full-speed range
● Driving safely is the sole responsibility of the driver. Do not rely solely on
the system, and drive safely by always paying careful attention to your sur-
roundings.
● The dynamic radar cruise control with full-speed range provides driving
assistance to reduce the driver’s burden. However, there are li mitations to
the assistance provided.
Read the following conditions carefully. Do not overly rely on this system
and always drive carefully.
• When the sensor may not be correctly detecting the vehicle ahead:
P. 328
• Conditions under which the vehicle-to-vehicle distance control mode may not function correctly: P. 330
● Set the speed appropriately depending on the speed limit, traffic flow, road
conditions, weather conditions, etc. The driver is responsible for checking
the set speed.
● Even when the system is functioning normally, the condition of the preced-
ing vehicle as detected by the system may differ from the condition
observed by the driver. Therefore, the driver must always remain alert,
assess the danger of each situation and drive safely. Relying s olely on this
system or assuming the system ensures safety while driving can lead to
an accident, resulting in death or serious injury.
● Switch the dynamic radar cruise control with full-speed range o ff using the
“ON-OFF” button when not in use.

PRIUS_OM_OM47D44U_(U)
3174-5. Using the driving support systems
4
Driving
WARNING
■Cautions regarding the driving assist systems
Observe the following precautions, as there are limitations to the assistance
provided by the system.
Failure to do so may cause an accident resulting in death or se rious injury.
● Assisting the driver to measure following distance
The dynamic radar cruise control with full-speed range is only intended to
help the driver in determining the following distance between the driver’s
own vehicle and a designated vehicle traveling ahead. It is not a mecha-
nism 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
driver to pay close attention to the vehicle’s surroundings.
● Assisting the driver to judge proper following distance
The dynamic radar cruise control with full-speed range determines
whether the following distance between the driver’s own vehicle and a
designated vehicle traveling ahead is within a set range. It is not capable
of making any other type of judgement. Therefore, it is absolutely neces-
sary for the driver to remain vigilant and to determine whether or not there
is a possibility of danger in any given situation.
● Assisting the driver to operate the vehicle
The dynamic radar cruise control with full-speed range does not include
functions which will prevent or avoid collisions with vehicles ahead of your
vehicle. Therefore, if there is ever any possibility of danger, the driver must
take immediate and direct control of the vehicle and act appropriately in
order to ensure the safety of all involved.

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PRIUS_OM_OM47D44U_(U)
4-5. Using the driving support systems
WARNING
■Situations unsuitable for dynamic radar cruise control with ful l-speed
range
Do not use dynamic radar cruise control with full-speed range in any of the
following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting in death or serious injury.
● Roads where there are pedestrians, cyclists, etc.
● In heavy traffic
● On roads with sharp bends
● On winding roads
● On slippery roads, such as those covered with rain, ice or snow
● On steep downhills, or where there are sudden changes between s harp up
and down gradients
Vehicle speed may exceed the set speed when driving down a stee p hill.
● At entrances to freeways and highways
● When weather conditions are bad enough that they may prevent the sen-
sors from detecting correctly (fog, snow, sandstorm, heavy rain, etc.)
● When there is rain, snow, etc. on the front surface of the rada r sensor or
camera sensor
● In traffic conditions that require frequent repeated acceleration and decel-
eration
● During emergency towing
● When an approach warning buzzer is heard often

PRIUS_OM_OM47D44U_(U)
3194-5. Using the driving support systems
4
Driving
This mode employs a radar sensor to detect the presence of vehi cles
up to approximately 328 ft. (100 m) ahead, determines the curre nt
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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PRIUS_OM_OM47D44U_(U)
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-ve hicle dis-
tance switch.
Example of deceleration crui sing 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 s peed 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 su ffi-
ciently to prevent your vehicle fr om 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 syst em then
returns to constant speed cruising.
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