wheel LEXUS RX450h 2021 Service Manual

2304-5. 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 either a
warning buzzer will sound or the steer-
ing wheel will vibrate to alert the driver.
When the warning buzzer sounds or the
steering wheel vibrates, check the area
around your vehicle and carefully operate
the steering wheel to move the vehicle
back to the center of the lane.
Vehicle with BSM: When the system deter-
mines that the vehicle might depart from its
lane and that the possibility of a collision
with an overtaking vehicle in the adjacent
lane is high, the lane departure alert will
operate even if the turn signals are operat-
ing.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
■Steering assist function
When the system determines that the
vehicle might depart from its lane or
course
*, the system provides assis-
tance 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-informat ion display and the
function is temporarily canceled.
Vehicle with BSM: When the system deter-
mines that the vehicle might depart from its
lane and that the po ssibility of a collision
with an overtaking vehicle in the adjacent
lane is high, the steering assist function will
operate even if the turn signals are operat-
ing.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
Functions included in LTA system

2314-5. Using the driving support systems
4
Driving
■Vehicle sway warning function
When the vehicle is swaying within a
lane, the warning buzzer will sound and
a message will be displayed on the
multi-information display to alert the
driver.
■Lane centering function
This function is linked with dynamic
radar cruise control with full-speed
range and provides the required assis-
tance by operating the steering wheel
to keep the vehicle in its current lane.
When dynamic radar cruise control 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 function
will operate to help follow a preceding
vehicle by monitoring the position of the
preceding vehicle.
If the system detect s 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-informat
ion display and the
function is temporarily canceled.
Press the LTA switch to turn the LTA
system on.
The LTA indicator illuminates and a mes-
sage is displayed on the multi-information
display.
Press the LTA switch again to turn the LTA
system off.
When the LTA system 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

2324-5. Using the driving support systems
LTA indicator
The illumination condition of the indicator
informs the driver of the system operation
status.
Illuminated in white: LTA system is operat-
ing.
Illuminated in green: Steering wheel assis-
tance 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 mu lti-information dis-
play is switched to the driving assist system
information screen. Indicates that steering
wheel assistance of
the steering assist function or lane center-
ing function is operating.
Both outer sides of the lane are displayed:
Indicates that steering wheel assist of the
lane centering function is operating.
One outer side of the lane is displayed:
Indicates that steering wheel assist of the
steering assist func tion is operating.
Both outer sides of the lane are flashing:
Alerts the driver that their input is neces-
sary to stay in the center of the lane (lane
centering function).
Lane departure alert function dis-
play
Displayed when the multi-information dis-
play is switched to th e driving assist system
information screen.
Inside of displayed lines is white
Indicates that the sy stem is recognizing
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.
Indications on multi-information
display
A
B
C

2334-5. Using the driving support systems
4
Driving
Inside of displayed white lines is
black
Indicates that the system is not able to
recognize white (yellow) lines or a
course
* or is temporarily canceled.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
Follow-up cruising display
Displayed when the mu lti-information dis-
play is switched to the driving assist system
information screen.
Indicates that steering assist of the lane
centering function is operating by monitor-
ing the position of a preceding vehicle.
When the follow-up cruising display is dis-
played, if the preceding vehicle moves,
your vehicle may move in the same way.
Always pay careful attention to your sur-
roundings 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 fol-
lowing conditions are met.
• LTA is turned on.
• Vehicle speed is approximately 32 mph (50 km/h) or more.
*1
•System recognizes wh ite (yellow) lane
lines or a course*2. (When a white [yel-
low] 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 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.235)
*1: The function operates even if the vehi-
cle speed is less than approximately 32
mph (50 km/h) when the lane center-
ing 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 fol-
lowing conditions are met in addition to the
operation conditions for the lane depar-
ture alert function.
• Setting for “Steering Assist” in of the multi-information display is set to “On”.
( P.88)
• Vehicle is not acceler ated or decelerated
by a fixed amount or more.
• Steering wheel is not operated with a steering force level su itable for changing
lanes.
• ABS, VSC, TRAC and PCS are not oper- ating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not
displayed. ( P.234)
●Vehicle sway warning function
This function operates when all of the fol-
lowing conditions are met.
• Setting for “Sway Warning” in of the multi-information display is set to “On”.
( P.88)
• Vehicle speed is approximately 32 mph
(50 km/h) or more.
• Width of traffic lane is approximately 9.8 ft. (3 m) or more.
• No system malfunctions are detected. ( P.235)
●Lane centering function
This function operates when all of the fol-
D

2344-5. Using the driving support systems
lowing conditions are met.
• LTA is turned on.
• Setting for “Steering Assist” and “Lane Center” in of the multi-information
display are set to “On”. ( P.88)
• This function recognizes white (yellow) lane lines or the position of a preceding
vehicle (except when the preceding vehi-
cle is small, such as a motorcycle).
• The dynamic radar cruise control with
full-speed range is operating in vehi-
cle-to-vehicle distance control mode.
• Width of traffic lane is approximately 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.235)
• Vehicle does not acc elerate or deceler-
ate by a fixed amount or more.
• Steering wheel is not operated with a
steering force level su itable for changing
lanes.
• ABS, VSC, TRAC and PCS are not oper-
ating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. ( P.234)
• The vehicle is being driven in the center of a lane.
• Steering assist function is not operating.
■Temporary cancelation of functions
●When operation conditions are no longer
met, a function may be temporarily can-
celed. However, when the operation con-
ditions are met again, operation of the
function is automa tically restored.
(  P.233)
●If the operation conditions ( P.233) 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 tem-
porarily canceled. However, if the “Alert”
customization setting is set to ,
the system will notify the driver by vibrat-
ing the steering wheel instead of sound-
ing the buzzer.
■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 oper-
ate 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 play-
back, etc. Also, it may be difficult to feel
steering wheel vibrations due to the road
conditions, etc.
●If the edge of the course* is not clear or
straight, the lane departure alert function
may not operate.
●Vehicle with BSM: It may not be possible
for the system to determine if there is a
danger of a collision with a vehicle in an
adjacent lane.
●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
■Hands off steering wheel warning
In the following situations, a warning mes-
sage urging the driver to hold the steering
wheel and the symbol sh own in the illustra-
tion are displayed on the multi-information
display to warn the driver. The warning
stops when the system determines that the
driver holds the steering wheel. Always
keep your hands on the steering wheel
when using this system , regardless of warn-
ings.

2354-5. Using the driving support systems
4
Driving
●When the system determines that the
driver is driving without holding the steer-
ing wheel while the system is operating
If the driver continue s to keep their hands
off of the steering wheel, the buzzer
sounds, the driver is warned and the func-
tion is temporarily ca nceled. This warning
also operates in the same way when the
driver continuously operates the steering
wheel only a small amount.
The buzzer also sounds even if the alert
type is set to .
●When the system determines that the
vehicle may deviate from the lane while
driving around a cu rve 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, warn-
ings will occur earlier than during
straight-lane driving.
●When the system determines that the
driver is driving without holding the steer-
ing wheel while the st eering wheel assist
of the steering assist function is operat-
ing.
If the driver continue s 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.
The buzzer also sounds even if the alert
type is set to .
■Vehicle sway warning function
When the system determines that the vehi-
cle is swaying while the vehicle sway warn-
ing function is operating, a buzzer sounds
and a warning message urging the driver to
rest and the symbol shown in the illustration
are simultaneously displayed on the
multi-information display. Depending on the vehicle and road condi-
tions, the warning may not operate.
■Warning message
If the following warning message is dis-
played on the multi-in formation display and
the LTA indicator illuminates in orange, fol-
low the appropriate troubleshooting proce-
dure. 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 your Lexus
dealer.
●“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 sys-
tem back on.
●“LTA Unavailable at Current Speed”
The function cannot be used as the vehicle
speed exceeds the LTA operation range.
Drive slower.
■Customization
Function settings can be changed. (Cus-
tomizable features: P.480)

2414-5. Using the driving support systems
4
Driving
328 ft. (100 m) ahead, determines the current vehicle-to-vehicle following dis-
tance, and operates to maintain a suitab le following distance from the vehicle
ahead. The desired vehicle-to-vehicle distance can also be set by operating the
vehicle-to-vehicle distance switch.
When driving on downhill slopes, the vehicl e-to-vehicle distance may become shorter.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver.
Example of deceleration cruising 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 speed 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 th e system cannot decelerate sufficiently to
prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehi cle will also stop (vehicle is stopped by sys-
tem control). After the vehicle ahead starts off, pushing the cruise control lever up 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 operated and yo ur vehicle moves to an overtaking lane while
driving at 50 mph (80 km/h) or more, the vehicle will accelerate to help to overtake a
passing vehicle.
The system’s identification of what is an over taking lane may be determined solely based on
the location of the steering wheel in the vehicl e (left side driver position versus right side
driver position.) If the vehicle is driven to a re gion where the overtaking lane is on a different
side from where the vehicle is normally driven, the vehicle may accelerate when the turn
A
B

2474-5. Using the driving support systems
4
Driving
●Preceding vehicle has an extremely high
ground clearance
■Conditions under which the vehi-
cle-to-vehicle distance control mode
may not function correctly
In the case of the following conditions,
operate the brake pedal (or accelerator
pedal, depending on the situation) as nec-
essary.
As the sensor may not be able to correctly
detect vehicles ahead, the system may not
operate properly.
●When the road curves or when the lanes
are narrow
●When steering wheel operation or your
position in the lane is unstable
●When the vehicle ahead of you deceler-
ates suddenly
●When driving on a road surrounded by a
structure, such as in a tunnel or on a
bridge
●While the vehicle speed is decreasing to
the set speed after the vehicle acceler-
ates by depressing the accelerator pedal
*: If equipped
Meter control switches
Turning the Blind Spot Monitor on/off.
BSM (Blind Spot Monitor)*
The Blind Spot Monitor is a system
that uses rear side radar sensors
installed on the inner side of the
rear bumper on the left and right
side to assist the driver in confirm-
ing safety when changing lanes.
WARNING
■Cautions regarding the use of the sys-
tem
The driver is solely responsible for safe
driving. Always drive safely, taking care
to observe your surroundings.
The Blind Spot Monitor is a supplemen-
tary function which alerts the driver that a
vehicle is in a blind spot of the outside
rear view mirrors or is approaching rap-
idly from behind into a blind spot. Do not
overly rely on the Blind Spot Monitor. As
the function cannot judge if it is safe to
change lanes, over re liance could lead to
an accident resulting in death or serious
injury.
As the system may not function correctly
under certain conditio ns, the driver’s own
visual confirmation of safety is necessary.
System components
A

2704-5. Using the driving support systems
●Change the traveling direction of the
vehicle
■If “Parking Support Brake Unavailable”
is displayed on the multi-information
display and the PKSB OFF indicator is
flashing
●If this message is displayed only when the
shift lever is in any position other than R, a
sensor on the front or rear bumper may
be dirty. Clean the sensors and their sur-
rounding area on the bumpers.
●Initialization may no t have been per-
formed after a 12-volt battery terminal
was disconnected and reconnected. Ini-
tialize the system. ( P.270)
If this message continues to be displayed
even after init ialization, have the vehicle
inspected by your Lexus dealer.
■If “Parking Assist Unavailable” and
“Parking Assist Unavailable Clean
Parking Assist Sensor” are displayed on
the multi-informatio n display and the
PKSB OFF indicator is flashing
●A sensor may be covered with ice, snow,
dirt, etc. Remove the ice, snow, dirt, etc.,
from the sensor to return the system to
normal.
If this message is shown even after
removing dirt from the sensor, or shown
when the sensor was not dirty to begin
with, have the vehicle inspected by your
Lexus dealer.
●A sensor may be frozen. Once the ice
melts, the system will return to normal.
●Water may be continuo usly flowing over
the sensor surface, such as in a heavy
rain. When the system determines that it
is normal, the system will return to nor-
mal.
■If a 12-volt battery terminal has been
disconnected and reconnected
The system needs to be initialized. To initial-
ize the system, drive the vehicle straight
ahead for 5 seconds or more at a speed of
approximately 22 mph (35 km/h) or more.
Additionally, for vehicles with the Parking
Support Brake function, turn the steering
wheel fully to the left and right with the vehi-
cle stopped.

2834-5. Using the driving support systems
4
Driving
economy through moderate throttle char-
acteristics and by controlling the operation
of the air conditioning system (heat-
ing/cooling).
When not in Eco drive mode, if the driving
mode select switch is turned to the left, the
Eco drive mode indicator will come on.
3Sport mode
Controls the hybrid system to provide
quick, powerful acceleration. This mode
also changes the steering feel, making it
suitable for when agil e driving response is
desired, such as when driving on roads
with many curves.
When not in sport mode, if the driving
mode select switch is turned to the right,
the “Sport” indicator will comes on.
■Operation of the air conditioning sys-
tem in Eco drive mode
Eco drive mode controls the heating/cool-
ing operations and fan speed of the air con-
ditioning system to enhance fuel efficiency.
To improve air condit ioning performance,
adjust the fan speed or turn off Eco drive
mode.
■Automatic deactivation of sport mode
and custom mode
If the power switch is turned off after driving
in sport mode or custom mode, the drive
mode will be changed to normal mode.
■Driving mode pop-up display (12.3-inch
display only)
When the driving mode is changed, the
selected driving mode will be temporarily
displayed on the side display. ( P.300)
■ECB (Electronically Controlled
Brake System)
The electronically controlled system
generates braking force correspond-
ing to the brake operation
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the
brakes are applied suddenly, or if the
brakes are applied while driving on a
slippery road surface
■Brake assist
Generates an increased level of brak-
ing force after the brake pedal is
depressed when the system detects a
panic stop situation
■VSC (Vehicle Stability Control)
Helps the driver to control skidding
when swerving sudden ly or turning on
slippery road surfaces
■Enhanced VSC (Enhanced Vehi-
cle Stability Control)
Provides cooperative control of the
ABS, TRAC, VSC and EPS.
Driving assist systems
To keep driving safety and perfor-
mance, the following systems oper-
ate automatically 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