TOYOTA PRIUS PLUG-IN HYBRID 2021 Owners Manual

4415-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
●Lane centering function
This function operates when all of the following conditions are met.
• LTA is turned on.
• Setting for (“LTA Steering Assist Mode”) and (“Center
Trace”) in of the multi-information display are set to “On”. (P. 230)
• This function recognizes white (yellow) lane lines or the position of a pre-
ceding vehicle (except when the preceding vehicle is small, such as a
motorcycle).
• The dynamic radar cruise control with full-speed range is operating in
vehicle-to-vehicle distance control mode.
• Width of traffic lane is approximately 3 to 4 m (10 to 13 ft.).
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. (P. 444)
• Vehicle does not accelerate or decelerate by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for
changing lanes.
• ABS, VSC, TRC and PCS are not operating.
• TRC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. (P. 443)
• The vehicle is being driven in the center of a lane.
• Steering assist function is not operating.

4425-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
■Temporary cancelation of functions
●When operation conditions are no longer met, a function may be temporarily
canceled. However, when the operation conditions are met again, operation
of the function is automatically restored. (P. 440)
●If the operation conditions (P. 441) are no longer met while the lane cen-
tering function is operating, the buzzer may sound to indicate that the func-
tion has been temporarily canceled.
■Steering assist function/lane centering 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.
●The steering control of the function is overridden by the driver’s steering
wheel operation.
●Do not attempt to test the operation of the steering assist function.
■Lane departure alert function
●The warning buzzer may be difficult to hear due to external noise, audio
playback, etc.
●If the edge of the course
* is not clear or straight, the lane departure alert
function may not operate.
●Do not attempt to test the operation of the lane departure alert function.
*: Boundary between asphalt and the side of the road, such as grass, soil, or
a curb

4435-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
■Hands off steering wheel warning
●When the system determines that the driver is driving without holding the
steering wheel while the system is operating
If the driver continues to keep their hands off of the steering wheel, the
buzzer sounds, the driver is warned and the function is temporarily can-
celed. This warning also operates in the same way when the driver continu-
ously operates the steering wheel only a small amount.
●When the system determines that the vehicle may deviate from the lane
while driving around a curve while the lane centering function is operating
Depending on the vehicle condition and road conditions, the warning may
not operate. Also, if the system determines that the vehicle is driving
around a curve, warnings will occur earlier than during straight-lane driving.
●When the system determines that the driver is driving without holding the
steering wheel while the steering wheel assist of the steering assist function
is operating.
If the driver continues to keep their hands off of the steering wheel and the
steering wheel assist is operating, the buzzer sounds and the driver is
warned. Each time the buzzer sounds, the continuing time of the buzzer
becomes longer.
■Vehicle sway warning function In the following situations, a warning mes-
sage urging the driver to hold the steering
wheel and the symbol shown in the illus-
tration are displayed on the multi-informa-
tion display to warn the driver. The
warning stops when the system deter-
mines that the driver holds the steering
wheel. Always keep your hands on the
steering wheel when using this system,
regardless of warnings.
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.

4445-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
■Warning message
If the following warning message is displayed on the multi-information display
and the LTA indicator illuminates in orange, follow the appropriate trouble-
shooting procedure. Also, if a different warning message is displayed, follow
the instructions displayed on the screen.
●“LTA Malfunction Visit Your Dealer”
The system may not be operating properly. Have the vehicle inspected by
any authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer.
●“LTA Unavailable”
The system is temporarily canceled due to a malfunction in a sensor other
than the front camera. Turn the LTA system off, wait for a little while, and
then turn the LTA system back on.
●“LTA Unavailable at Current Speed”
The function cannot be used as the vehicle speed exceeds the LTA opera-
tion range. Drive slower.
■Customization
Function settings can be changed.
(Customizable features:P. 257)

4455-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
RSA (Road Sign Assist)
The RSA system recognizes spe-
cific road signs using the front
camera and/or navigation system
(when speed limit information is
available) to provide information
to the driver via the display.
If the system judges that the vehicle is being driven over the speed
limit, performing prohibited actions, etc. according to the recognized
road signs, it notifies the driver through a visual notification and notifi-
cation buzzer.
Summary of function
WARNING
■ Before using the RSA
Do not rely solely upon the RSA system. RSA is a system which supports
the driver by providing information, but it is not a replacement for a driver’s
own vision and awareness. Drive safely by always paying careful attention
to the traffic rules.

4465-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
When the front camera recognizes a sign and/or information of a sign
is available from the navigation system, the sign will be displayed on
the main display or multi-information display.
●When the driving assist system
information is selected in multi-
information display, a maximum
of 2 signs can be displayed on
the multi-information display.
(P. 230)
●When a tab other than the driv-
ing assist system information is
selected, the following types of
road signs will be displayed on
the main display. (P. 222)
• Speed limit begins/ends sign
• Speed limit related informa-
tion sign (Expressway,
Highway, Urban area, Resi-
dential area)
• End of prohibition sign
• No-entry sign
* (when notification is necessary)
• Speed limit with supplemental sign (Ramp way only)
*: For vehicles with navigation system
If signs other than speed limit signs are recognized, they will be displayed
in an overlapping stack under the current speed limit sign.
Indication on the main display or multi-information display

4475-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
The following types of road signs, including electronic signs and blink-
ing signs, are recognized.
A non-official (not meeting the Vienna Convention) or a recently introduced
traffic sign may not be recognized.
●Speed limit road signs
●Speed limit related information
*
*
: Displayed when a sign is recognized but speed limit information for the
road is not available from the navigation system
●No-overtaking road signs
Supported types of road signs
Speed limit begins/
Maximum speed zone
beginsSpeed limit ends/Maxi-
mum speed zone ends
Expressway entranceUrban area ending
Expressway exitUrban area beginning
Highway entranceUrban area ending
Highway exitResidential area begin-
ning
Urban area beginningResidential area end-
ing
No overtaking beginsNo overtaking ends

4485-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
●Other road signs
*: For vehicles with navigation system
●Speed limit with supplemental mark*1
*1: Displayed simultaneously with speed limit.
*2: Contents not recognized.
*3: If the turn signal indicator is not operated when changing lanes, the mark
does not display.
No-entry*Stop
End of prohibition
WetExit ramp on right*3
RainExit ramp on left*3
IceTime
Supplemental mark
exists
*2

4495-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
In the following situations, the RSA system will notify the driver.
●When the vehicle speed exceeds the speed notification threshold of
the speed limit sign displayed, the sign display will be emphasized
and a buzzer will sound.
●When the RSA system recognizes a no-entry sign and detects that
the vehicle has entered a no-entry area based on the map informa-
tion of the navigation system, the no-entry sign flashes and a
buzzer will sound.(For vehicles with navigation system)
●If it is detected that your vehicle is overtaking when a no overtaking
sign is displayed on the multi-information display, the displayed sign
will flash and a buzzer will sound.
Depending on the situation, traffic environment (traffic direction,
speed unit) may be detected incorrectly and a notification function
may not operate properly.
■Setting procedure
P. 257
■Automatic turn-off of RSA sign display
One or more signs automatically turn off in the following situations.
●No sign has been recognized for a certain distance.
●The road changes due to a left or right turn, etc.
■Conditions in which the function may not operate or detect correctly
In the following situations, RSA does not operate normally and may not rec-
ognize signs, display the incorrect sign, etc. However, this does not indicate a
malfunction.
●The front camera is misaligned due to a strong impact being applied to the
sensor, etc.
●Dirt, snow, stickers, etc. are on the windshield near the front camera.
●In inclement weather such as heavy rain, fog, snow or sand storms
●Light from an oncoming vehicle, the sun, etc. enters the front camera.
●The sign is dirty, faded, tilted or bent.
●The contrast of electronic sign is low.
●All or part of the sign is hidden by the leaves of a tree, a pole, etc.
●The sign is only visible to the front camera for a short amount of time.
●The driving scene (turning, lane change, etc.) is judged incorrectly.
●If a sign not appropriate for the currently traveled lane, but the sign exists
directly after a freeway branches, or in an adjacent lane just before merging.
Notification function

4505-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
●Stickers are attached to the rear of the preceding vehicle.
●A sign resembling a system compatible sign is recognized.
●Side road speed signs may be detected and displayed (if positioned in sight
of the front camera) while the vehicle is traveling on the main road.
●Roundabout exit road speed signs may be detected and displayed (if posi-
tioned in sight of the front camera) while traveling on a roundabout.
●The front of the vehicle is raised or lowered due to the carried load
●The surrounding brightness is not sufficient or changes suddenly.
●When a sign intended for trucks, etc. is recognized.
●The vehicle is driven in a country with a different direction of traffic.
●The navigation system map data is outdated.
●The navigation system is not operating.
●The speed information displayed on the meter and on the navigation system
may be different due to the navigation system using map data.
■Speed limit sign display
If the power switch was last turned off while a speed limit sign was displayed
on the main display or multi-information display, the same sign displays again
when the power switch is turned to ON mode.
■If “RSA Malfunction Visit Your Dealer” is shown
The system may be malfunctioning. Have the vehicle inspected by any autho-
rized Toyota retailer or Toyota authorized repairer, or any reliable repairer.
■Customization
Some functions can be customized. (Customizable features: P. 782)