2020 LEXUS LS500H lane assist

2154-5. Using the driving support systems
4
Driving
●In some situations, such as the following,
the sensors may not detect the lane lines
or a safe space the vehicle can be steered
into, preventing the active steering assist
from operating properly:
• When the white (yellow) lane lines are
difficult to see, such as when they are
faint, diverging/merging, or a shadow is
cast upon them
• When the lane is more wide or narrow than normal
• When there is a light and dark pattern on
the road surface, such as due to road
repairs
• If the system determines that a collision
can be avoided by only using the brakes
• When a pedestrian is detected near the centerline of the vehicle
●In some situations such as the following,
sufficient braking force or steering force
may not be obtained, preventing the sys-
tem 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 surface
• If there are deep ruts in the road
• When driving on a slope
• When driving on a horizontally slanted road
●Some guardrails, such as the following,
may not be detected by the sensors, pre-
venting the system from operating prop-
erly:
• Guardrails which are less than approxi-
mately 1.9 ft. (60 cm) tall
• Short guardrails
• Irregularly-shaped guardrails (wire cable guardrails, guardrails made of thin poles,
etc.)
• Guardrails which are not illuminated by the headlights at night, in a tunnel, etc.
• Guardrails which appear to be nearly the
same color or brightness as their sur-
roundings
• Guardrails which appear to be nearly the
same shape as their surroundings (walls,
etc.) • Guardrails which are over a metal object
(manhole cover, steel plate, etc.)
• Guardrails which are hidden behind thick
grass
• Guardrails which are extremely close to the side of the vehicle (outside rear view
mirror, etc.)
• Curved guardrails or guardrails at the entrance of a curve
●In some situations su ch as the following,
the system may detect a pedestrian and
display a warning on the head-up display,
even though no pedestrian exists:
• If the front of the vehicle is raised or low-
ered, such as when the road surface is
uneven or undulating (due to ruts, etc.)
• When driving on a slope
• When driving on a horizontally slanted
road
• If the driver’s posture (driver seat posi-
tion) is extreme, such as excessively
reclined
• If the head-up display position is set
extremely high
■If VSC is disabled
●If VSC is disabled ( P.297), the pre-col-
lision brake assist and pre-collision brak-
ing 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.

2264-5. 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.
When driving on highways and free-
ways with white (yellow) lane lines, this
function alerts the driver when the
vehicle might depart from its lane or
course
* and provides assistance by
operating the steering wheel to keep
the vehicle in its lane or course
*. Fur-
thermore, the system provides steering
assistance when dynamic radar cruise
control with full-speed range is operat-
ing to keep the vehicle in its lane 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

2274-5. 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.
●When tires of a size other than speci-
fied are installed.
●Vehicle is driven in traffic lanes other
than that highways and freeways.
●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
■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.

2304-5. 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. If the
steering assist function is canceled, release
the steering wheel and then grip it again to
enable the function.
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.

2314-5. 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.175)
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.
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.

2324-5. 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.175)
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.
Turning LTA system on
Indications on multi-information
display
A

2334-5. Using the driving support systems
4
Driving
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 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

2344-5. 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 ap proximately 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.238)
Indications on head-up display
(vehicles with Lexus Safety Sys-
tem + A)