steering wheel LEXUS LS500 2021 Service Manual

2384-5. Using the driving support systems
■If the PCS warning light illuminates and
a message is displayed on the
multi-information display
The system may be temporarily unavailable
or may be malfunctioning.
While driving on a road with clear
white (yellow) lane lines, the LTA sys-
tem 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 devia-
tion 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
and when changing lanes (vehicles
with Lexus Safety System + A).
The LTA system recognizes white (yel-
low) lane lines or a course
* using the
front camera. Additionally, it detects
preceding and surrounding vehicles
(vehicles with Lexus Safety System +
A) using the front camera and radar.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
LTA (Lane Tracing Assist)
Summary of function

2394-5. Using the driving support systems
4
Driving
WARNING
■Before using LTA system
●Do not rely solely upon the LTA sys-
tem. 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 pay-
ing 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 acc ident, 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.
■Situations in whic h the lane change
assist function should not be used
●When driving on a one lane road or
road without lane markers
●When there is no broken white line
between your vehicle and the lane
toward which the turn signal is oper-
ated
●Vehicle is driven in traffic lanes other
than that freeways and highways.
■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 Lexus 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, con-
tact your Lexus dealer.
■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 la ne. 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.

2414-5. Using the driving support systems
4
Driving
■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 po ssibility 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
WARNING
●The traffic lines are yellow (which may
be more difficult to recognize than
lines that are white).
●The white (yellow) lines cross over a
curb, etc.
●The vehicle is driven on a bright sur-
face, such as concrete.
●If the edge of the road is not clear or
straight.
●The vehicle is driven on a surface that
is bright due to reflected light, etc.
●The vehicle is driven in an area where
the brightness changes suddenly, such
as at the entrances and exits of tunnels,
etc.
●Light from the headlights of an oncom-
ing vehicle, the sun, etc. enters the
camera.
●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 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 conditions
during driving (poor roads or road
seams).
●When driving in a tunnel or at night
with the headlights off or when a head-
light is dim due to its lens being dirty or
it being misaligned.
●The vehicle is struck by a crosswind.
●The vehicle is affected by wind from a
vehicle driven in a nearby lane.
●The vehicle has just changed lanes or
crossed an intersection.
●Tires which differ by structure, manu-
facturer, brand or tread pattern are
used.
●When tires of a size other than speci-
fied are installed.
●Snow tires, etc. are equipped.
●The vehicle is being driven at
extremely high speeds.
Functions included in LTA system

2424-5. Using the driving support systems
■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 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-information 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 possibility of a collision
with an overtaking vehicle in the adjacent
lane is high, the steeri ng 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
■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.

2434-5. Using the driving support systems
4
Driving
■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-information display and the
function is temporarily canceled.
■Lane change assist function (vehi-
cles with Lexus Safety System + A)
This function is linked to the dynamic
radar cruise control with full-speed
range and provides assistance for per-
forming lane changes by operating the
steering wheel when you hold the turn
signal lever partway (lane change posi-
tion). ( P.185)
When lane change assist function is
operating, the acceleration and decel-
eration of the vehicle is controlled
while the preceding vehicle and vehi-
cles driven in the lane toward which the
turn signal is oper ated are monitored.
Use lane change assist function on
freeways and highways.
When the lane center ing function is not
operating, the lane change assist function
will not operate.
The lane change assist function should not
be operated when ch anging lanes on a
road that is diverging or merging.

2444-5. Using the driving support systems
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
engine is started.
■Lane change assist function (vehi-
cles with Lexus Safety System + A)
Hold the turn signal lever partway
(lane change position) for approxi-
mately 1 second.( P.185)
The direction you are signaling will be dis-
played on the multi-information display.
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
Turning LTA system on
Indications on multi-information
display
A

2454-5. Using the driving support systems
4
Driving
function is operating.
Operation display of steering
wheel operation support
Displayed when the multi-information dis-
play is switched to the driving support sys-
tem informat ion display.
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 function 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 mu lti-information dis-
play is switched to the driving support sys-
tem informat ion display.
Inside of displayed lines is white
Indicates that the system 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.
Inside of displayed 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 multi-information dis-
play is switched to the driving support sys-
tem information display.
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.
■Lane change assist function (vehi-
cles with Lexus Safety System + A)
 Lane change assist display
B
C
D

2464-5. Using the driving support systems
Indicates that steering wheel assist of the
lane change assist function is operating.
 Approaching vehicle warning dis-
play
Indicates that an approaching vehicle is
detected in the adjacent lane.
■Warning display (vehicles with
Lexus Safety System + A)
When the lane centering function is oper-
ating and the system determines that the
vehicle may depart from its lane due to a
sharp curve, etc., a warning display urging
the driver to operate the steering wheel,
will be displayed.
This display will also be displayed when
operation of the lane change assist func-
tion is canceled.
In some situations a warning display may
not be displayed.
Some displays, which are the same as
those displayed on the multi-informa-
tion display, will be displayed.
■LTA system curve display on the
head-up display
The curve display on the head-up display
changes according to the direction and
curvature of the curve.
■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 white (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.250)
Indications on head-up display
(vehicles with Lexus Safety Sys-
tem + A)

2474-5. Using the driving support systems
4
Driving
*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 me t 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.82)
• Vehicle is not accelerated 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.249)
●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.82)
• 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.250)
●Lane centering function
This function operates when all of the fol-
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.82)
• 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.250)
• Vehicle does not ac celerate 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.249)
• The driver has one or both hands on the steering wheel. (vehicles with Lexus
Safety System + A)
• The vehicle is being driven in the center of a lane.
• Steering assist function is not operating.
●Lane change assist fu nction (vehicles with
Lexus Safety System + A)
This function will operate when all of the
following conditions are met:
• The lane centering function is operating.
• “Lane Change Assist” is set to “ON” in of the multi-information dis-
play.( P.82)
• The vehicle speed is between approxi- mately 57 and 85 mph (90 and 140
km/h).
• White (yellow) lane lines are detected by
the system.
• A broken white line is detected between your vehicle and the lane toward which
the turn signal is operated.
• The turn signal lever is held partway (lane change position) for approximately 1 sec-
ond.
• A vehicle is not overtaking your vehicle
or detected in the lane toward which the
turn signal is operated.
• The vehicle is being driven straight or
around a slight curve.
• The vehicle is not a ccelerating or decel-
erating more than a certain amount.
• The steering wheel is not being turned sufficiently to perf orm a lane change.

2484-5. Using the driving support systems
• 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.249)
• The dynamic radar cruise control with
full-speed range approach warning is not
operating.
• The lane departure alert function is not
operating.
• The curve speed reduction function ( P.260) 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.246)
●If the operation conditions ( P.246) 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.
●If the operating conditions ( P.246) are
no longer met, the buzzer may sound to
indicate that the lane change assist func-
tion has been temporarily canceled.
(vehicles with Lexus Safety System + A)
■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.
●Even if the curve speed reduction func-
tion ( P.260) operates, the lane center-
ing function may not be able to drive the
vehicle around a curve successfully.
(vehicles with Lexus Safety System + A)
●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
■Lane change assist function (vehicles
with Lexus Safety System + A)
Depending on the vehicle speed, vehicle
condition, road conditions, or conditions of
the area around the vehicle, the lane
change assist function may not operate or it
may be difficult to recognize that it has
operated.
If steering control oper ation is excessive or
insufficient, it can be corrected by the
driver’s operation of the steering wheel.
In situations such as the following, the lane
change assist function may be canceled:
●When the system no longer detects white
(yellow) lane lines
●When the turn signal lever is operated
fully (right/left turn position)
●When the vehicle speed is outside of the
operational range of the function
●When the system detects operation of
the steering wheel, brake or accelerator
pedal by the driver
While the lane change assist function is
operating, if the system detects that a vehi-
cle is quickly approaching in the lane
toward which the turn signal is operated,
the steering assist may slightly steer the
vehicle away from the la ne while a buzzer is
sounding, the steering wheel is vibrating,