
2334-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving
Press the LKA switch to turn the LKA
system on.WARNING■
Before using LKA system
Do not rely solely upon the LKA system.
The LKA system does not automatically
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 driv-
ing safely by paying careful attention to
the surrounding conditions and operat-
ing 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. ■
To avoid operating LKA system by
mistake
When not using the LKA system, use the
LKA switch to turn the system off. ■
Situations unsuitab le for LKA system
Do not use the LKA system in the follow-
ing situations.
The system may not operate properly
and lead to an accident, resulting in
death or serious injury.
●
A spare tire, tire chains, etc. are
equipped.
●
When the tires have been excessively
worn, or when the tire inflation pres-
sure is low.
●
Tires which differ by structure, manu-
facturer, brand or tread pattern are
used.
●
Objects or patterns that could be mis-
taken for white (yellow) lines are pres-
ent on the side of th e road (guardrails,
curbs, reflective poles, etc.).
●
Vehicle is driven on a snow-covered
road.
●
White (yellow) lines are difficult to see
due to rain, snow, fog, dust, etc. ●
Asphalt repair marks, white (yellow)
line marks, etc. are present due to road
repair. ●
Vehicle is driven in a temporary lane or
restricted lane due to construction
work. ●
Vehicle is driven on a road surface
which is slippery due to rainy weather,
fallen snow, freezing, etc. ●
Vehicle is driven in traffic lanes other
than on highways and freeways. ●
Vehicle is driven in a construction
zone. ■
Preventing LKA 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.
Turning LKA system on

236 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) function is automatically restored.
( → P.235)■
Steering assist function/lane centering
function
Depending on the vehicle speed, lane
departure situation, ro ad conditions, etc.,
the driver may not feel the function is oper-
ating or the function may not operate at all.■
Lane departure alert function
The warning buzzer may be difficult to hear
due to external noise, audio playback, etc.
Also, it may be difficult to feel steering
wheel vibrations due to the road conditions,
etc. ■
Hands off steering wheel alert
When the system determines that the driver
has removed the hands from the steering
wheel while the steering assist function or
lane centering function is operating, a warn-
ing message is displaye d on the multi-infor-
mation display. If the driver continues to
keep the hands off of the steering wheel, a
warning message is displayed and the func-
tion is temporarily canceled. This alert also
operates in the same way when the driver
continuously operates the steering wheel
only a small amount. However, depending
on the road conditions , etc., the function
may not cancel. ■
White (yellow) lines ar e only on one side
of road
The LKA system will not operate for the
side on which white (yellow) lines could not
be recognized. ■
Conditions in whic h functions may not
operate properly
In the following situations, the camera sen-
sor may not detect white (yellow) lines and
various functions may not operate normally.
●
There are shadows on the road that run
parallel with, or cover, the white (yellow)
lines.
●
The vehicle is driven in an area without
white (yellow) lines, such as in front of a
tollgate or checkpoint, or at an intersec-
tion, etc.
●
The white (yellow) lines are cracked,
“Botts’ dots”, “Raised pavement marker” or stones are present. ●
The white (yellow) lines cannot be seen
or are difficult to see due to sand, etc. ●
The vehicle is driven on a road surface
that is wet due to rain, puddles, etc. ●
The traffic lines are yellow (which may be
more difficult to reco gnize than lines that
are white). ●
The white (yellow) lines cross over a curb,
etc. ●
The vehicle is driven on a bright surface,
such as concrete. ●
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 sudd enly, such as at
the entrances and exits of tunnels, etc. ●
Light from the headlights of an oncoming
vehicle, the sun, etc. enters the camera. ●
The vehicle is driven where the road
diverges, merges, etc. ●
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 vehicle is driven around a sharp
curve. ●
The traffic lane is excessively narrow or
wide. ●
The vehicle is extremely tilted due to car-
rying 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).
●
The headlight lenses are dirty and emit a
faint amount of light at night, or the beam
axis has deviated.
●
The vehicle is struck by a crosswind.
●
The vehicle has just changed lanes or
crossed an intersection.
●
Snow tires, etc. are equipped.

244 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) This mode employs a radar sensor to detect the presence of vehicles up to approx-
imately 328 ft. (100 m) ahead, determines the current vehicle-to-vehicle following
distance, and operates to maintain a suit able following distance from the vehicle
ahead. Note that vehicle-to-vehicle di stance will close in when trav eling on long downhill slopes.
Example of constant speed cruising
When there are no vehicles aheadThe vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle distance
can also be set by operating the ve hicle-to-vehicle distance switch.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appearsWhen 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 sy stem 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 decelera te 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, pressing the “+RES” switch or depressing
the accelerator pedal will resume follow-up cruising.
Vehicles with Lexus Safety System+A: If your vehicle is being driven at approximately 43
mph (70 km/h) or more, when the turn signal is operated and a lane change is made to
pass the vehicle ahead, the system will start acce lerating your vehicle up to the set speed to
assist smooth overtaking.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set Driving in vehicle-to-vehicle distance control mode
A
B
C

270 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) • Pedestrians who are bending forward or
squatting
• Pedestrians who are lying down
• Pedestrians who are running
• Pedestrians who suddenly enter the
detection area
• Pedestrians riding a bicycle, skateboard,
or other light vehicle
• Pedestrians wearing oversized clothing
such as a rain coat, long skirt, etc., making
their silhouette obscure
• Pedestrians whose body is partially hid-
den by an object, such as a cart or
umbrella
• Pedestrians which are obscured by dark-
ness, such as at night●
In some situations, such as the following,
pedestrians may not be detected by the
rear camera detection function, prevent-
ing 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 sud-
denly, such as at the entrance or exit of a
garage or underground parking lot
• When backing up in a dim environment
such as during dusk or in an underground
parking lot●
Even though there are no pedestrians in
the detection area, some objects, such as
the following, may be detected, possibly
causing the rear camera detection func-
tion to operate.
• Three dimensional objects, such as a
pole, traffic cone, fence, or parked vehi-
cle
• Moving objects, such as a car or motor-
cycle
• Objects moving toward your vehicle
when backing up, such as flags or pud-
dles (or airborne matter, such as smoke,
steam, rain, or snow)
• Cobblestone or gravel roads, tram rails,
road repairs, white lines, pedestrian
crossings or fallen leaves on the road
• Metal covers (gratings), such as those
used for drainage ditches • Objects reflected in a puddle or on a wet
road surface
• The roadside or bumps on the road
•Shadows on the road ●
In some situations, such as the following,
the rear camera detection function may
operate even though there are no pedes-
trians in the detection area.
• When backing up toward the roadside or
a bump on the road
• If the vehicle is signif icantly tilted, such as
when carrying a heavy load
• When backing up toward an
incline/decline
• If the suspension has been modified or
tires of a size othe r than specified are
installed
• If the rear of the vehicle is raised or low-
ered due to the carried load
• If an electronic component, such as a
backlit license plate or rear fog light, is
installed near the rear camera
• If a bumper protector, such as an addi-
tional trim strip, is installed to the rear
bumper
• If the orientation of the rear camera has
been changed due to a collision or other
impact, or removal and installation
• If a towing eyelet is in stalled to the rear of
the vehicle
• When water is flowing over the rear cam-
era lens
• When the rear camera is obscured (dirt,
snow, ice, etc. are at tached) or scratched
• If there is a flashing light in the detection
area, such as the emergency flashers of
another vehicle ●
Situations in which the rear camera
detection function may be difficult to
notice
• If buzzer may be difficult to hear if the
surrounding area is noisy, the volume of
the audio system volume is high, the air
conditioning system is being used, etc.
• If the temperature in the cabin is
extremely high or low, the audio system
screen may not operate correctly.

2814-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving ●
Weather
• If a sensor is covered with ice, snow, dirt,
etc. (when cleared, the system will return
to normal)
• If heavy rain or water strikes a sensor
• When driving in incl ement weather such
as fog, snow or a sandstorm●
Other ultrasonic wave sources
• When vehicle horns, vehicle detectors,
motorcycle engines, air brakes of large
vehicles, the clearance sonar of other
vehicles or other devices which produce
ultrasonic waves are near the vehicle
• If a sticker or an el ectronic component,
such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
sensor●
Changes in the vehicle posture
• If the vehicle is significantly tilted
• If the front of the vehicle is raised or low-
ered due to the carried load
• If the orientation of a sensor has been
changed due to a collision or other
impact■
Situations in which the Parking Support
Brake function (stati c objects) may not
operate properly
In some situations, such as the following, this
function may not operate properly. ●
Weather
• When a sensor or the area around a sen-
sor is extremely hot or cold
• When strong winds are blowing • If a sensor is covered with ice, snow, dirt,
etc. (when cleared, the system will return
to normal)
• If heavy rain or water strikes a sensor
• When driving in incl ement weather such
as fog, snow or a sandstorm ●
Vehicle surroundings
• When an object that cannot be detected
is between the vehicle and a detected
object
• If an object such as a vehicle, motorcycle,
bicycle or pedestrian cuts in front of the
vehicle or runs out from the side of the
vehicle ●
Other ultrasonic waves sources
• When vehicle horns, vehicle detectors,
motorcycle engines, air brakes of large
vehicles, the clearance sonar of other
vehicles or other de vices which produce
ultrasonic waves are near the vehicle
• If a sticker or an electronic component,
such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
sensor ●
Changes in the vehicle posture
• If the vehicle is significantly tilted
• If the front of the vehicle is raised or low-
ered due to the carried load
• If the orientation of a sensor has been
changed due to a collision or other
impact

2854-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving let, bumper protector (an additional trim
strip, etc.), bicycle carrier, or snow plow●
If the suspension has been modified or
tires of a size other than specified are
installed●
If the front of the vehicle is raised or low-
ered due to the carried load●
If a sticker or an electronic component,
such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
radar sensor●
If the orientation of a radar sensor has
been changed●
When multiple vehicles are approaching
with only a small gap between each vehi-
cle●
If a vehicle is approaching the rear of
your vehicle rapidly ●
Situations in which the radar sensor may
not detect a vehicle
• When a vehicle approaches from the
right or left at the rear of the vehicle while
you are turning while backing up
• When turning while backing up
• When backing out of a shallow angle
parking spot • When backing up on a slope with a sharp
change in grade
• When a vehicle turns into the detection
area

2874-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving ■
Parking Support Brake function (rear
pedestrians) will operate when
The function will oper ate when the PKSB
OFF indicator is not illuminated or flashing
( → P.65, 66) and all of the following condi-
tions are met: ●
Engine output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 10 mph (15 km/h) or
less.
• The shift position is in R.
• The rear camera sensor detects a pedes-
trian behind the vehicle while backing up
and the system determines that the possi-
bility of colliding with the detected
pedestrian is high.●
Brake control
• Engine output restriction control is oper-
ating
• The Parking Support Brake determines
that an emergency brake operation is
necessary to avoid a collision with a
pedestrians.■
The Parking Support Brake function
(rear pedestrians) will stop operating
when
The function will stop operating if any of the
following conditions are met:
●
Engine output restriction control
• The Parking Support Brake is disabled.
• The collision becomes avoidable with
normal brake operation.
• The pedestrian is no longer detected
behind your vehicle.
●
Brake control
• The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed
since the vehicle was stopped by brake control.
• The brake pedal is depressed after the
vehicle is stopped by brake control.
• The pedestrian is no longer detected
behind your vehicle. ■
Detection area of the Parking Support
Brake function (rear pedestrians)
The detection area of the Parking Support
Brake function (rear pedestrians) differs
from the detection area of the RCD func-
tion ( → P.269). Therefore, even if the RCD
function detects a vehicle and provides an
alert, the Parking Support Brake function
(rear-crossing vehicles) may not start oper-
ating. ■
Situations in which the system may not
operate properly ●
Some pedestrians, such as the following,
may not be detected by the Parking Sup-
port Brake function (rear pedestrians),
preventing the function from operating
properly:
• Pedestrians who are bending forward or
squatting
• Pedestrians who are lying down
• Pedestrians who are running
• Pedestrians who suddenly enter the
detection area
• Pedestrians riding a bicycle, skateboard,
or other light vehicle
• Pedestrians wearing oversized clothing
such as a rain coat, long skirt, etc., making
their silhouette obscure
• Pedestrians whose body is partially hid-
den by an object, such as a cart or
umbrella
• Pedestrians which are obscured by dark-
ness, such as at night ●
In some situations, such as the following,
pedestrians may not be detected by the
Parking Support Brake function (rear
pedestrians), 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 at tached) 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 sud-WARNING■
If the Parking Support Brake function
(rear pedestrians) operates unneces-
sarily
Depress the brake pedal immediately
after the Parking Support Brake function
(rear pedestrians) operates. (Operation
of the function is canceled by depressing
the brake pedal.)

294 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) ■
ECB (Electronically Controlled
Brake System) (if equipped)
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. ■
Secondary Collision Brake
When the airbag sensor detects a colli-
sion, the brakes and brake lights are
automatically controlled to reduce the vehicle speed and that helps reduce
the possibility of further damage due to
a secondary collision. ■
TRAC (Traction Control)
Helps to maintain drive power and pre-
vent the drive wheels from spinning
when starting the vehicle or accelerat-
ing on slippery roads ■
Hill-start assist control
Helps to reduce the backward move-
ment of the vehicle when starting on an
uphill ■
VGRS (Variable Gear Ratio Steer-
ing) (if equipped)
Adjusts the front wheel turning angle in
accordance with the vehicle speed and
steering wheel movement ■
DRS (Dynamic Rear Steering) (if
equipped)
Contributes to the turning characteris-
tics and responsiveness of the vehicle
by adjusting the rear wheel angle of the
vehicle in accordance with steering
wheel movement. ■
EPS (Electric Power Steering)
Employs an electric motor to reduce
the amount of effort needed to turn the
steering wheel. ■
Active stabilizer suspension sys-
tem (if equipped)
Reduces sway when cornering accord-
ing to steering wheel movement in
order to maintain a stable vehicle pos-
ture.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