wheel TOYOTA SIENNA HYBRID 2021 (in English) Repair Manual

2804-5. 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 control
with full-speed range is not operat-
ing, the lane centering function
does not operate.
In situations where the white (yel-
low) lane lines are difficult to see or
are not visible, such as when in a
traffic jam, this fu nction will operate
to help follow a preceding vehicle
by monitoring the position of the
preceding vehicle.
If the system detects that the steer-
ing 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 can-
celed.
Press the LTA switch to turn the
LTA system on.
The LTA indicator illuminates and a
message is display
ed on the multi-
information display.
Press the LTA switch again to
turn the LTA system off.
When the LTA syste m is turned on
or off, operation of the LTA system
continues in the same condition the
next time the hybrid system is
started.
Turning LTA system on

2814-5. Using the driving support systems
4
Driving
LTA indicator
The illumination condition of the
indicator informs the driver of the
system operation status.
Illuminated in white: LTA system is
operating.
Illuminated in green: Steering
wheel assistance of the steering
assist function or lane centering
function is operating.
Flashing in orange: Lane departure
alert function is operating.
Operation display of steering
wheel operation support
Displayed when the multi-informa-
tion display is switched to the driv-
ing support system information
display.
Indicates that steering wheel assis-
tance of the steering assist function or lane centering f
unction is operat-
ing.
Both outer sides of the lane are dis-
played: Indicates that steering
wheel assist of the lane centering
function is operating.
One outer side of the lane is dis-
played: Indicates that steering
wheel assist of the steering assist
function is operating.
Both outer sides of the lane are
flashing: Alerts the driver that their
input is necessary to stay in the
center of the lane (lane centering
function).
Follow-up cruising display
Displayed when the multi-informa-
tion display is swit ched to the driv-
ing support system information
display.
Indicates that steering assist of the
lane centering function is operating
by monitoring the position of a pre-
ceding vehicle.
When the follow-up cruising display
is displayed, if t he preceding vehi-
cle moves, your ve hicle may move
in the same way. Always pay care-
ful attention to your surroundings
and operate the steering wheel as
necessary to correct the path of the
vehicle and ensure safety.
Lane departure alert function
display
Displayed when the multi-informa-
tion display is swit ched to the driv-
ing support system information
display.
Indications on multi-infor-
mation display
A
B
C
D

2824-5. Using the driving support systems
Inside of displayed lines is
white
Indicates that the system is recog-
nizing white (yellow) lines or a
course
*. When the vehicle departs
from its lane, the white line dis-
played on the si de the vehicle
departs from flashes orange.
Inside of displayed lines is
black
Indicates that the system is not able
to recognize white (yellow) lines or
a course
* or is temporarily can-
celed.
*: Boundary between asphalt and the side of the road, such as
grass, soil, or a curb
■Operation conditions of each
function
●Lane departure alert function
This function oper ates when all of
the following cond itions 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 approxi-
mately 9.8 ft. (3 m) or more.
• Turn signal lever is not operated. (Vehicle with BSM: Except when
another vehicle is in the lane on
the side where the turn signal was
operated)
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are
detected. ( P.285)
*1: The function oper ates even if the
vehicle speed is less than
approximately 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
addition to the operation conditions
for the lane departure alert function.
• Setting for “Steering Assist” in the
screen of the multi-information
display is set to “ON”. ( P.104)
• 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.284)
●Vehicle sway warning function

2834-5. Using the driving support systems
4
Driving
This function operates when all of
the following cond itions are met.
• Setting for “Sway Warning” in the
screen of the mu lti-information
display is set to “ON”. ( P.104)
• Vehicle speed is approximately 32 mph (50 km/h) or more.
• Width of traffic lane is approxi- mately 9.8 ft. ( 3 m) or more.
• No system malfunctions are detected. ( P.285)
●Lane centering function
This function oper ates when all of
the following cond itions are met.
• LTA is turned on.
• Setting for “Steering Assist” and
“Lane Center” in the screen of
the multi-information display are
set to “ON”. ( P.104)
• This function recognizes white (yellow) lane lines or the position
of a preceding 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-vehic le distance con-
trol mode.
• Width of traffic lane is approxi-
mately 10 to 13 ft. (3 to 4 m).
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. ( P.285)
• 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, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning
is not displayed. ( P.284)
• The vehicle is being driven in the
center of a lane.
• Steering assist function is not operating.
■Temporary cancelation of func-
tions
●When operation conditions are no
longer met, a function may be
temporarily canceled. However,
when the operation conditions are
met again, operation of the func-
tion is automatically restored.
( P.282)
●If the operation conditions
( P.282) are no longer met while
the lane centering function is
operating, the steering wheel may
vibrate and the buzzer may sound
to indicate that the function has
been temporarily canceled. How-
ever, if the “Steering wheel vibra-
tion” customization setting is set to
“On”, the system will notify the
driver by vibrating the steering
wheel instead of sounding the
buzzer.
■Steering assist function/lane
centering function
●Depending on the vehicle speed,
lane departure situation, road con-
ditions, etc., the driver may not
feel the function is operating or
the function may not operate at
all.
●The steering control of the func-
tion is overridden by the driver’s
steering wheel operation.
●Do not attempt to test the opera-
tion of the steering assist function.
■Lane departure alert function
●The warning buzzer may be diffi-
cult to hear due to external noise,
audio playback, etc. Also, it may
be difficult to fee l steering wheel
vibrations due to the road condi-
tions, etc.
●If the edge of the course* is not
clear or straight, the lane depar-
ture alert function may not oper-
ate.
●Vehicle with BSM: It may not be
possible for the system to deter-
mine if there is a danger of a colli-

2844-5. Using the driving support systems
sion with a vehicle in an adjacent
lane.
●Do not attempt to test the opera-
tion of the lane departure alert
function.
*: Boundary between asphalt and
the side of the road, such as
grass, soil, or a curb
■Hands off steering wheel warn-
ing
In the following situations, a warning
message urging the driver to hold
the steering wheel and the symbol
shown in the illustration are dis-
played on the multi-information dis-
play to warn the driver. The warning
stops when the sys tem determines
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 the
driver is not holding the steering
wheel while the lane centering
function 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 con-
tinuously operates the steering
wheel only a small amount.
The buzzer also sounds even if the
alert type is set to “Steering wheel
vibration”.
●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 driv-
ing around a curve, warnings will
occur earlier than during straight-
lane driving.
●When the system determines that
the driver is driving without hold-
ing the steering wheel while the
steering wheel assi st of the steer-
ing assist function is operating.
If the driver continues to keep their
hands off of the steering wheel and
the steering wheel assist is operat-
ing, the buzzer sounds and the
driver is warned. Each time the
buzzer sounds, the continuing time
of the buzzer becomes longer.
The buzzer also sounds even if the
alert type is set to “Steering wheel
vibration”.
■Vehicle sway warning function
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 sym bol shown in the
illustration are simultaneously dis-
played on the multi-information dis-
play.
Depending on the vehicle and road
conditions, the warning may not
operate.

2924-5. 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.
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 runni ng ahead of you, the system automatically
decelerates your vehicle. When a greater reduction in vehicle s peed is nec-
essary, the system applies the brakes (the stop lights will come on at this
time). The system will respond to changes i n the speed of the vehicle
ahead in order to maintain the ve hicle-to-vehicle distance set by the driver.
Approach warning warns you when the system cannot decelerate suffi-
ciently to prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you st ops, your vehicle will also stop (vehicle is
stopped by system control). Afte r the vehicle ahead starts off, pressing the
“+RES” switch or depressing the accelerator pedal (start-off operation) will
resume follow-up cruising. If the start-off operation is not performed, system
control continues to keep your vehicle stopped.
When the turn signal lever is ope rated and your vehicle moves to an over-
taking lane while driving at 50 mph (80 km/h) or more, the vehi cle will accel-
erate to help to overt ake a passing vehicle.
The system’s identifi cation of what is an overtaking lane may be deter-
mined solely based on the location of the steering wheel in the vehicle (left
side driver position versus righ t side driver position.) If the vehicle is driven
to a region where the overtaking lane is on a different side fr om where the
vehicle is normally driven, the v ehicle may accelerate when the turn signal
lever is operated in the opposite direction to the overtaking l ane (e.g., if the
driver normally operates the vehicle in a region where the over taking lane is
to the right but then drives to a region where the overtaking l ane is to the
left, the vehicle may accelerate when the right turn signal is activated).
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 system then
returns to constan t speed cruising.
1Press the cruise control main switch to activate the cruise
control.
Dynamic radar cruise control indi-
cator will come on and a message
will be displayed on
the multi-infor-
mation display. Press the switch
A
B
C
Setting the vehicle speed
(vehicle-to-vehicle dis-
tance control mode)

2994-5. Using the driving support systems
4
Driving
●When steering wheel operation or
your position in the lane is unsta-
ble
●When the vehicle ahead of you
decelerates suddenly
●When driving on a road sur-
rounded by a structure, such as in
a tunnel or on a bridge
*: If equipped
BSM (Blind Spot Moni-
tor)*
The Blind Spot Monitor is a
system that has 2 functions:
The BSM (Blind Spot Moni-
tor) function
Assists the driver in making a
decision when changing lanes
 The RCTA (Rear Cross
Traffic Alert) function
Assists the driver when back-
ing up
These functions use the
same sensors.
WARNING
■Cautions regarding the use of
the BSM function
The driver is solely responsible for
safe driving. Always drive safely,
taking care to observe your sur-
roundings.
The BSM function is a supple-
mentary function which alerts the
driver that a vehicle is in a blind
spot of the outside rear view mir-
rors or is approaching rapidly from
behind into a blin d spot. Do not
overly rely on the BSM function.
As the function cannot judge if it is
safe to change lanes, over reli-
ance could lead to an accident
resulting in dea th or serious
injury.
As the system may not function
correctly under certain condi-
tions, the driver’s own visual con-
firmation of safety is necessary.

3174-5. Using the driving support systems
4
Driving
■The rear camera detection func-
tion is operational when
●The power switch is in ON.
●RCD function is on.
●The shift lever is in R.
■Setting the buzzer volume
The buzzer volume can be adjusted
on the multi-inform ation display.
(  P.112)
■Muting the buzzer sound
The buzzer can be temporarily
muted by pressing “OK” of the meter
control switches w hile a suggestion
that says mute is available is shown
on the multi-info rmation display.
■If “Rear Camera Detection
Unavailable Remove the Dirt of
Rear Camera” is displayed on
the multi-information display
A rear camera lens may be dirty or
covered with snow or ice. In such
cases, if it is removed from the rear
camera lens, the system should
return to normal. ( It may be neces-
sary to drive the vehicle for some
time before the system returns to
normal. Even afte r the camera
cleaning washer operated, driving
the vehicle may al so be necessary.)
■If “Rear Camera Detection
Unavailable See Owner’s Man-
ual” is displayed on the multi-
information display
●If this message is displayed after
the 12-volt battery has been dis-
connected and reconnected, fully
turn the steering wheel to the left
and then the right on level ground.
●If this message is displayed only
when the shift lever is in R, the
rear camera lens may be dirty.
Clean the rear camera lens.
■Situations in which the system
may not operate properly
●Some pedestrians, such as the
following, may not be detected by
the rear camera detection func- tion, preventing the function from
operating properly:
• Pedestrians who are bending for-
ward or squatting
• Pedestrians who are lying down
• Pedestrians who are running
• Pedestrians who suddenly enter the detection area
• People riding a bicycle, skate-
board, or other light vehicle
• Pedestrians wearing oversized clothing such as a rain coat, long
skirt, etc., making their silhouette
obscure
• Pedestrians whose body is par-
tially hidden by an object, such as
a cart or umbrella
• Pedestrians which are obscured
by darkness, such as at night
●In some situations, such as the
following, pedestrians may not be
detected by the rear camera
detection function, preventing the
function from operating properly:
• When backing up in inclement weather (rain, snow, fog, etc.)
• When the rear camera is obscured (dirt, snow, ice, etc. are
attached) or scratched
• When a very bright light, such as the sun, or the headlights of
another vehicle, shines directly
into the rear camera
• When backing up in a place where the surrounding brightness
changes suddenly, such as at the
entrance or exi t of a garage or
underground parking lot
• When backing up in a dim envi- ronment such as during dusk or in
an underground parking lot
• When the dedicated camera cleaning washer is operating
●Even though there are no pedes-
trians in the detection area, some
objects, such as the following,
may be detected, possibly caus-
ing the rear cam era detection
function to operate.
• Three dimensional objects, such
as a pole, traffic cone, fence, or
parked vehicle
• Moving objects, such as a car or

3354-5. Using the driving support systems
4
Driving■ECB (Electronically Con-
trolled Brake System)
The electronically controlled
system generates braking force
corresponding to the brake
operation
■ABS (Anti-lock Brake Sys-
tem)
Helps to prevent wheel lock
when the brakes are applied
suddenly, or if the brakes are
applied while driving on a slip-
pery road surface
■Brake assist
Generates an increased level of
braking force after the brake
pedal is depressed when the
system detects a panic stop sit-
uation
■VSC (Vehicle Stability Con-
trol)
Helps the driver to control skid-
ding when swerving suddenly or
turning on slippery road sur-
faces.
■Enhanced VSC (Enhanced
Vehicle Stability Control)
Provides cooperative control of
the ABS, TRAC, VSC and EPS.
Helps to maintain directional
stability when swerving on slip-
pery road surfaces by con-
trolling steering performance.
■Trailer Sway Control
Helps the driver to control trailer
sway by selectively applying
brake pressure for individual
wheels and reducing driving
torque when trailer sway is
detected.
■TRAC (Traction Control)
Helps to maintain drive power
and prevent the drive wheels
from spinning when starting the
vehicle or accelerating on slip-
pery roads
■Active Cornering Assist
(ACA)
Helps to prevent the vehicle
from drifting to the outer side by
performing inner wheel brake
control when attempting to
accelerate while turning
■Hill-start assist control
Helps to reduce the backward
Driving assist systems
To keep driving safety and
performance, the following
systems operate automati-
cally in response to various
driving situations. Be
aware, however, that these
systems are supplementary
and should not be relied
upon too heavily when oper-
ating the vehicle.
Summary of the driving
assist systems

3364-5. Using the driving support systems
movement of the vehicle when
starting on an uphill
■EPS (Electric Power Steer-
ing)
Employs an electric motor to
reduce the amount of effort
needed to turn the steering
wheel
■E-Four (Electronic On-
Demand AWD system)
(AWD models)
Automatically switches from
front wheel drive to all-wheel
drive (AWD) according to the
driving conditions, helping to
ensure reliable handling and
stability. Examples of condi-
tions where the system will
switch to AWD are when corner-
ing, going uphill, starting off or
accelerating, and when the road
surface is slippery due to snow,
rain, etc.
■The Secondary Collision
Brake
When the airbag sensor detects
a collision, the brakes and brake
lights are automatically con-
trolled to reduce the vehicle
speed and that helps reduce the
possibility of further damage
due to a secondary collision
■When the
TRAC/VSC/ABS/Trailer Sway
Control systems are operating
The slip indicator will flash while the
TRAC/VSC/ABS/Trai ler Sway Con-
trol systems are operating.
■Disabling the TRAC system
If the vehicle gets stuck in mud, dirt
or snow, the TRAC system may
reduce power from the hybrid sys-
tem to the wheels.
Pressing to turn the system off
may make it easier for you to rock
the vehicle in order to free it.
To turn the TRAC system off,
quickly press and release .
“Traction Control Turned Off” will be
shown on the multi-information dis-
play.
Press again to turn the system
back on.
■Turning off the
TRAC/VSC/Trailer Sway Con-
trol systems
To turn the TRAC/VSC/Trailer Sway
Control systems of f, press and hold
for more than 3 seconds while
the vehicle is stopped.
The VSC OFF indicator light will
come on and the “Traction Control
Turned Off” will be shown on the
multi-informat ion display.
*
Press again to turn the systems
back on.