wheel TOYOTA PRIUS PRIME 2021 (in English) Service Manual

PRIUS PRIME_OM_OM47D71U_(U)
3935-5. Using the driving support systems
5
Driving
• If a vehicle ahead is narrow, such as a personal mobility vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shaped, such as a tractor or side car
• If a vehicle ahead is a child sized bicycle, a bicycle that is carrying a large
load, a bicycle ridden by more than one person, or a uniquely shaped
bicycle (bicycle with a child seat, tandem bicycle, etc.)
• If a pedestrian/or the riding height of a bicyclist ahead is shorter than
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50004400570048004f005c0003001900110018000300490057[. (2 m)
• If a pedestrian/bicyclist is wearing oversized clothing (a rain coat, long
skirt, etc.), making their silhouette obscure
• If a pedestrian is bending forward or squatting or bicyclist is bending for-
ward
• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a stroller, wheelchair, bicycle or other vehicle
• When driving in inclement weather such as heavy rain, fog, snow or a
sandstorm
• When driving through steam or smoke
• When the surrounding area is dim, such as at dawn or dusk, or while at
night or in a tunnel, making a detectable object appear to be nearly the
same color as its surroundings
• When driving in a place where the surrounding brightness changes sud-
denly, such as at the entrance or exit of a tunnel
• After the hybrid system has started the vehicle has not been driven for a
certain amount of time
• While making a left/right turn and for a few seconds after making a left/
right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding • If a preceding vehicle has a low rear
end, such as a low bed trailer
• If a vehicle ahead has extremely high
ground clearance

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PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
• If the wheels are misaligned
• If a wiper blade is blocking the front camera
• The vehicle is being driven at extremely high speeds
• When driving on a hill
• If the radar sensor or front camera is misaligned
●In some situations such as the following, sufficient braking force may not be
obtained, preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when
the brake parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively
worn, improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery sur-
face
■If VSC is disabled
●If VSC is disabled (P. 503), the pre-collision brake assist and pre-collision
braking functions are also disabled.
●The PCS warning light will turn on and “VSC Turned Off Pre-Collision Brake
System Unavailable” will be displayed on the multi-information display. • If the front of the vehicle is raised or
lowered

395
PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
5
Driving
LTA (Lane Tracing Assist)
While driving on a road with clear white (yellow) lane lines, the LTA
system warns the driver if the vehicle may deviate from the current
lane or course
*, and also can slightly operate the steering wheel to
help avoid deviation from the lane or course
*. Also, while the dynamic
radar cruise control with full-speed range is operating, this system will
operate the steering wheel to maintain the vehicle’s lane position.
The LTA system recognizes white
(yellow) lane lines or a course
*
using the front camera. Addition-
ally, it detects preceding vehicles
using the front camera and radar.
*: Boundary between asphalt and the
side of the road, such as grass, soil,
or a curb
Summary of functions

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PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
WARNING
■Before using LTA system
●Do not rely solely upon the LTA system. The LTA system does not auto-
matically drive the vehicle or reduce the amount of attention that must be
paid to the area in front of the vehicle. The driver must always assume full
responsibility for driving safely by paying careful attention to the surround-
ing conditions and operating the steering wheel to correct the path of the
vehicle. Also, the driver must take adequate breaks when fatigued, such
as from driving for a long period of time.
●Failure to perform appropriate driving operations and pay careful attention
may lead to an accident, resulting in death or serious injury.
●When not using the LTA system, use the LTA switch to turn the system off.
■Situations unsuitable for LTA system
In the following situations, use the LTA switch to turn the system off. Failure
to do so may lead to an accident, resulting in death or serious injury.
●Vehicle is driven on a road surface which is slippery due to rainy weather,
fallen snow, freezing, etc.
●Vehicle is driven on a snow-covered road.
●White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.
●Vehicle is driven in a temporary lane or restricted lane due to construction
work.
●Vehicle is driven in a construction zone.
●A spare tire, tire chains, etc. are equipped.
●When the tires have been excessively worn, or when the tire inflation pres-
sure is low.
●During emergency towing.
■Preventing LTA system malfunctions and operations performed by
mistake
●Do not modify the headlights or place stickers, etc. on the surface of the
lights.
●Do not modify the suspension etc. If the suspension etc. needs to be
replaced, contact your Toyota dealer.
●Do not install or place anything on the hood or grille. Also, do not install a
grille guard (bull bars, kangaroo bar, etc.).
●If your windshield needs repairs, contact your Toyota dealer.

PRIUS PRIME_OM_OM47D71U_(U)
3975-5. Using the driving support systems
5
Driving
WARNING
■Conditions in which functions may not operate properly
In the following situations, the functions may not operate properly and the
vehicle may depart from its lane. Drive safely by always paying careful
attention to your surroundings and operate the steering wheel to correct the
path of the vehicle without relying solely on the functions.
●When the follow-up cruising display is displayed (P. 405) and the pre-
ceding vehicle is swaying. (Your vehicle may sway accordingly and depart
from the lane.)
●When the follow-up cruising display is displayed (P. 405) and the pre-
ceding vehicle departs from its lane. (Your vehicle may follow the preced-
ing vehicle and depart from the lane.)
●When the follow-up cruising display is displayed (P. 405) and the pre-
ceding vehicle is being driven extremely close to the left/right lane line.
(Your vehicle may follow the preceding vehicle and depart from the lane.)
●Vehicle is being driven around a sharp curve.
●When the follow-up cruising display is
displayed (P. 405) and the preceding
vehicle changes lanes. (Your vehicle
may follow the preceding vehicle and
also change lanes.)
●Objects or patterns that could be mis-
taken for white (yellow) lines are pres-
ent on the side of the road (guardrails,
reflective poles, etc.).

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PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
■Lane departure alert function
When the system determines
that the vehicle might depart
from its lane or course
*, a
warning is displayed on the
multi-information display, and a
warning buzzer will sound to
alert the driver.
When the warning buzzer
sounds, check the area around
your vehicle and carefully oper-
ate the steering wheel to move
the vehicle back to the center of
the lane.
*: Boundary between asphalt and the side of the road, such as grass, soil, or
a curb
Functions included in LTA system

PRIUS PRIME_OM_OM47D71U_(U)
4015-5. Using the driving support systems
5
Driving
■Steering assist function
When the system determines
that the vehicle might depart
from its lane or course
*, the
system provides assistance as
necessary by operating the
steering wheel in small
amounts for a short period of
time to keep the vehicle in its
lane.
If the system detects that the
steering wheel has not been
operated for a fixed amount of
time or the steering wheel is not
being firmly gripped, a warning
is displayed on the multi-infor-
mation display and the function
is temporarily canceled.
*: Boundary between asphalt and the side of the road, such as grass, soil, or
a curb
■
Vehicle sway warning function
When the vehicle is swaying
within a lane, the warning
buzzer will sound and a mes-
sage will be displayed on the
multi-information display to alert
the driver.

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PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
■Lane centering function
This function is linked with
dynamic radar cruise control
with full-speed range and pro-
vides the required assistance
by operating the steering wheel
to keep the vehicle in its current
lane.
When dynamic radar cruise con-
trol with full-speed range is not
operating, the lane centering
function does not operate.
In situations where the white
(yellow) lane lines are difficult to
see or are not visible, such as
when in a traffic jam, this func-
tion will operate to help follow a
preceding vehicle by monitoring
the position of the preceding
vehicle.
If the system detects that the steering wheel has not been operated for
a fixed amount of time or the steering wheel is not being firmly gripped,
a warning is displayed on the multi-information display and the function
is temporarily canceled.

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PRIUS PRIME_OM_OM47D71U_(U)
5-5. Using the driving support systems
LTA i n d i c a t o r
The illumination condition of the
indicator informs the driver of
the system operation status.
Illuminated in green: LTA sys-
tem is operating.
Flashing in orange: Lane
departure alert function is oper-
ating.
Steering control indicator and operation display of steering wheel
operation support
When that steering wheel assistance of the steering assist function
or lane centering function is operating, the indicator illuminates and
the operation display on the multi-information display is turned on.
Lane departure alert function display
Displayed when the multi-information display is switched to the
driving assist system information screen.
*: Boundary between asphalt and the side of the road, such as grass, soil, or
a curb
Indications on combination meter
1
2
3
Inside of displayed lines is
whiteInside of displayed lines is
black
Indicates that the system is recog-
nizing white (yellow) lines or a
course
*. When the vehicle
departs from its lane, the white
line displayed on the side the
vehicle departs from flashes
orange.Indicates that the system is not
able to recognize white (yellow)
lines or a course* or is temporar-
ily canceled.

PRIUS PRIME_OM_OM47D71U_(U)
4055-5. Using the driving support systems
5
Driving
Follow-up cruising display
Displayed when the multi-information display is switched to the driving
assist system information screen.
Indicates that steering assist of the lane centering function is operating by
monitoring the position of a preceding vehicle.
When the follow-up cruising display is displayed, if the preceding vehicle
moves, your vehicle may move in the same way. Always pay careful atten-
tion to your surroundings and operate the steering wheel as necessary to
correct the path of the vehicle and ensure safety.
■Operation conditions of each function
●Lane departure alert function
This function operates when all of the following conditions are met.
• LTA is turned on.
• Vehicle speed is approximately 32 mph (50 km/h) or more.
*1
• System recognizes white (yellow) lane lines or a course*2. (When a white
[yellow] line or course
*2 is recognized on only one side, the system will
operate only for the recognized side.)
• Width of traffic lane is approximately 9.8 ft. (3 m) or more.
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. (P. 409)
*1: The function operates even if the vehicle speed is less than approxi-
mately 32 mph (50 km/h) when the lane centering function is operating.
*2: Boundary between asphalt and the side of the road, such as grass, soil,
or a curb
●Steering assist function
This function operates when all of the following conditions are met in addi-
tion to the operation conditions for the lane departure alert function.
• Setting for (“LTA Steering Assist Mode”) in of the multi-
information display is set to “On”. (P. 220)
• Vehicle is not accelerated or decelerated by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for
changing lanes.
• ABS, VSC, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. (P. 408)
4