high LEXUS LS500 2019 Service Manual

198 4-5. Using the driving support systems
LS500_OM_(U)_1810 *
:If equipped
■
PCS (Pre-Collision System) (vehi-
cles with Lexus Safety System +
2.0)
 P.215 ■
LTA (Lane Tracing Assist)
 P.225 ■
AHB (Automatic High Beam)
 P.182 ■
RSA (Road Sign Assist) *
 P.247 *
:If equipped ■
Dynamic radar cruise control with
full-speed range
 P.237 Two types of sensors, located behind
the front grille and windshield, detect
information necessary to operate the
drive assist systems.
Radar sensor
Front cameraLexus Safety System + 2.0 *
The Lexus Safety System + 2.0 con-
sists of the following drive assist sys-
tems and contributes to a safe and
comfortable driving experience:
Driving assist system WARNING■
Lexus Safety System + 2.0
The Lexus Safety System + 2.0 is
designed to operate under the assump-
tion that the driver will drive safely, and is
designed to help reduce the impact to
the occupants and the vehicle in the case
of a collision or assist the driver in normal
driving conditions.
As there is a limit to the degree of recog-
nition accuracy and control performance
that this system can provide, do not
overly rely on this system. The driver is
always responsible for paying attention
to the vehicle’s surroundings and driving
safely.
Sensors
WARNING
■
To avoid malfunction of the radar sen-
sor
Observe the following precautions.
Otherwise, the radar sensor may not
operate properly, possibly leading to an
accident resulting in death or serious
injury. A
B

202 4-5. Using the driving support systems
LS500_OM_(U)_1810 ■
If a warning message is displayed on the multi-information display
A system may be temporarily unavailable or there may be a malfunction in the system.●
In the following situations, perform the actions specified in the table. When the normal
operating conditions are detected, the me ssage will disappear and the system will
become operational.
If the message does not disappea r, contact your Lexus dealer.
Situation Actions
When the area around a sensor is covered
with dirt, moisture (f ogged up, covered with
condensation, ice, etc.), or other foreign
matter To clean the part of the windshield in front of
the front camera , use the windshield wipers
or the windshield defo gger of the air condi-
tioning system (  P.314).
When the temperature around the front
camera is outside of the operational range,
such as when the vehicle is in the sun or in an
extremely cold environment If the front camera is hot, such as after the
vehicle had been parked in the sun, use the
air conditioning system to decrease the tem-
perature around the front camera.
If a sunshade was used when the vehicle
was parked, depending on its type, the sun-
light reflected from the surface of the sun-
shade may cause the temperature of the
front camera to become excessively high.
If the front camera is cold, such after the
vehicle is parked in an extremely cold envi-
ronment, use the air conditioning system to
increase the temperature around the front
camera.

204 4-5. Using the driving support systems
LS500_OM_(U)_1810 ■
Pedestrian alert
When the system determines that
there is a possibility of a frontal collision
with a stationary or moving pedestrian
in front of your vehicle, a message will
be displayed on the head-up display to
warn the driver. ■
Pre-collision warning
When the system determines that the
possibility of a frontal collision is high, a
buzzer will sound and a warning mes-
sage will be displayed on the
multi-information display to urge the
driver to take evasive action.
■
Pre-collision brake assist
When the system determines that the
possibility of a frontal collision is high,
the system applies greater braking
force in relation to how strongly the
brake pedal is depressed. ■
Pre-collision braking
If the system determines that the possi-
bility of a frontal collision is extremely
high, the brakes are automatically
applied to help avoid the collision or
reduce the impact of the collision. ■
Active steering assist
If the system determines that the possi-PCS (Pre-Collision System)
(vehicles with Lexus Safety
System + A) The pre-collision system uses a
front radar sensor and front camera
to detect vehicles and pedestri-
ans/bicyclists in front of your vehi-
cle and front side radar sensors to
detect vehicles approaching from
the front left or right side. When the
system determines that the possi-
bility of a frontal collision with a
vehicle or pedestrian/bicyclist is
high, a warning operates to urge
the driver to take evasive action
and the potential brake pressure is
increased to help the driver avoid
the collision. If the system deter-
mines that the possibility of a frontal
collision with a vehicle or pedes-
trian/bicyclist is extremely high, the
brakes are automatically applied to
help avoid the collision or help
reduce the impact of the collision.
The pre-collision system can be dis-
abled/enabled and the warning tim-
ing can be changed. (  P.208)
System functions

2054-5. Using the driving support systems
LS500_OM_(U)_1810 4
Driving bility of a collision with an object, such
as a guardrail, or pedestrian is high,
even though the brakes are applied,
and that the collision may be avoidable
through steering control, the system
will steer the vehicle automatically to
help avoid the collision or help reduce
the impact of the collision. ■
Pre-collision seat belts (front seat
only)
If the system determines that the possi-
bility of a frontal collision is high, the
system will retract the seat belts. Addi-
tionally, the system may retract the seat
belts if the brakes are applied suddenly
or control of the vehicle is lost. ■
Pre-collision seatbacks (front pas-
senger’s seat / power rear seat [if
equipped])
If the system determines that the possi-
bility of a frontal collision is high, it may
move the seatbacks of the front pas-
senger’s seat and power rear seats to
the upright position automatically, if
reclined. If a seat is being ad justed, it may not be
moved by the pre-collision seat function.
■
Suspension control
When the system determines that the
possibility of a frontal collision is high,
the Adaptive Variable Suspension Sys-
tem (  P.295) will control the damp-
ing force of the shock absorbers to
help maintain an appropriate vehicle
posture. ■
Steering control
When the system determines that the
possibility of a frontal collision is high and the driver is op erating the steering
wheel, the LDH system (  P.295) will
control the turning angle of the front
and rear wheels and effort necessary
to turn the steering wheel to help
enhance steering responsiveness. WARNING■
Limitations of the pre-collision system ●
The driver is solely responsible for safe
driving. Always drive safely, taking
care to observe your surroundings.
Do not use the pre-collision system
instead of normal braking operations
under any circumstances. This system
will not prevent collisions or lessen col-
lision damage or injury in every situa-
tion. Do not overly rely on this system.
Failure to do so may lead to an acci-
dent, resulting in death or serious
injury. ●
Although this system is designed to
help avoid a collision or help reduce
the impact of the collision, its effective-
ness may change according to various
conditions, therefore the system may
not always be able to achieve the same
level of performance.
Read the following conditions care-
fully. Do not overly rely on this system
and always drive carefully.
• Conditions under which the system
may operate even if there is no possi-
bility of a collision:  P.210
• Conditions under which the system
may not operate properly:  P.212
●
Do not attempt to test the operation of
the pre-collision system yourself.
Depending on the objects used for
testing (dummies, cardboard objects
imitating detectable objects, etc.), the
system may not operate properly, pos-
sibly leading to an accident.

208 4-5. Using the driving support systems
LS500_OM_(U)_1810 ■
Changing the pre-collision warn-
ing timing
The pre-collision warning timing can
be changed on (  P.80) of the
multi-information display. The warning
timing for the pedestrian and FCTA
(Front Cross Traffic Alert) system will
also be changed. The warning timing se tting is retained
when the engine switch is turned off. How-
ever, if the pre-collision system is disabled
and re-enabled, the operation timing will
return to the default setting (middle).
1 Early
2 Middle This is the default setting.
3 Late ■
Changing the pedestrian alert tim-
ing
If the pre-collision warning timing is
changed, the pedestrian alert and
FCTA (Front Cross Traffic Alert) timing
will also be changed accordingly.■
Operational conditions
The pre-collision system is enabled and the system determines that the possibility of a frontal
collision with a vehicle, pedestri an/bicyclist, guardrail, etc. or a front side collision with a
vehicle is high. Each function is operational at the following speeds:●
Pedestrian alert
●
Pre-collision warning objects Vehicle speed
Pedestrians Approx. 20 to 40 mph (30 to 65 km/h)
objects Vehicle speed Relative speed between your
vehicle and object
Preceding vehicles Approx. 3 to 110 mph (5 to
180 km/h) Approx. 3 to 110 mph (5 to
180 km/h)
Bicyclists and pedestrians Approx. 3 to 50 mph (5 to
80 km/h) Approx. 3 to 50 mph (5 to
80 km/h)

2134-5. Using the driving support systems
LS500_OM_(U)_1810 4
Driving • If a vehicle ahead has extremely high
ground clearance
• If a vehicle ahead is carrying a load which
protrudes past its rear bumper
• If a vehicle ahead is irregularly shaped,
such as a tractor or side car
• If a vehicle ahead is a child sized bicycle,
a bicycle that is carrying a large load, a
bicycle ridden by more than one person,
or a uniquely shaped bicycle (bicycle with
a child seat, tandem bicycle, etc.)
• If a pedestrian/or the riding height of a
bicyclist ahead is shorter than approxi-
mately 3.2 ft. (1 m) or taller than approxi-
mately 6.5 ft. (2 m)
• If a pedestrian/bicyclist is wearing over-
sized clothing (a rain coat, long skirt,
etc.), making their silhouette obscure
• If a pedestrian is bending forward or
squatting or bicyclist is bending forward
• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a stroller, wheel-
chair, bicycle or other vehicle
• When driving in incl ement weather such
as heavy rain, fog, snow or a sandstorm
• When driving through steam or smoke
• When the surrounding area is dim, such
as at dawn or dusk, or while at night or in
a tunnel, making a vehicle, pedestrian or
bicyclist appear to be nearly the same
color as its surroundings
• When driving in a place where the sur-
rounding brightness changes suddenly,
such as at the entrance or exit of a tunnel
• When driving in a lo cation where there are many objects which reflect radar,
such as a tunnel or parking garage
• After the engine has started the vehicle
has not been driven for a certain amount
of time
• While making a left/r ight turn and for a
few seconds after making a left/right turn
• While driving on a curve and for a few
seconds after driving on a curve
• If your vehicle is skidding
• If the front of the vehicle is raised or low-
ered
• If the wheels are misaligned
• If a wiper blade is blocking the front cam-
era
• The vehicle is being driven at extremely
high speeds.
• When driving on a hill
• If the radar sensor or front camera is mis-
aligned
• If the headlights are misaligned
• When approaching a guardrail at a wide
or narrow angle
• When a vehicle approaches your vehicle
from the front left or right side while your
vehicle is entering an intersection with
poor visibility
• When a vehicle approaches your vehicle
from the rear left or right side
• When a vehicle approaches the side of
your vehicle at a shallow angle
• When driving on a road with a grade that
changes sharply (sha rp incline/decline)
• Pedestrians and bicyclists which are not
illuminated by the head lights at night, in a
tunnel, etc.
• Pedestrians and bicyclists which change
speed or direction abruptly
• Pedestrians and bicyclists which suddenly
emerge from behind a vehicle or large
object
• Pedestrians and bicyclists which are
extremely close to the side of the vehicle
(outside rear view mirror, etc.)

214 4-5. Using the driving support systems
LS500_OM_(U)_1810 ●
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 ac tive 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 brig htness 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.294), 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.

2154-5. Using the driving support systems
LS500_OM_(U)_1810 4
Driving
The system can detect the following:
 Vehicles
 Bicyclists
 Pedestrians
■
Pre-collision warning
When the system determines that the
possibility of a frontal collision is high, a
buzzer will sound and a warning mes- sage will be displayed on the
multi-information display to urge the
driver to take evasive action.
■
Pre-collision brake assist
When the system determines that the
possibility of a frontal collision is high,
the system applies greater braking
force in relation to how strongly the
brake pedal is depressed. ■
Pre-collision braking
If the system determines that the possi-
bility of a frontal collision is extremely
high, the brakes are automatically
applied to help avoid the collision or
reduce the impact of the collision. ■
Pre-collision seatbacks (front pas-
senger’s seat / power rear seat [if
equipped])
If the system determines that the possi-
bility of a frontal collision is high, it may
move the seatbacks of the front pas-
senger’s seat and power rear seats to
the upright position automatically, if
reclined. If a seat is being adjusted, it may not be
moved by the pre-collis ion seat function.
■
Suspension control
When the system determines that the
possibility of a frontal collision is high, PCS (Pre-Collision System)
(vehicles with Lexus Safety
System + 2.0) The pre-collision system uses a
radar sensor and front camera to
detect objects (  P.215) in front of
the vehicle. When the system
determines that the possibility of a
frontal collision with an object is
high, a warning operates to urge
the driver to take evasive action
and the potential brake pressure is
increased to help the driver avoid
the collision. If the system deter-
mines that the possibility of a frontal
collision with an object is extremely
high, the brakes are automatically
applied to help avoid the collision or
help reduce the impact of the colli-
sion.
The pre-collision system can be dis-
abled/enabled and the warning tim-
ing can be changed. (  P.217)
Detectable objects
System functions

216 4-5. Using the driving support systems
LS500_OM_(U)_1810 the Adaptive Variable Suspension Sys-
tem (  P.295) will control the damp-
ing force of the shock absorbers to
help maintain an appropriate vehicle
posture. ■
Steering control
When the system determines that the
possibility of a frontal collision is high
and the driver is operating the steering
wheel, the LDH system (  P.295) will
control the turning angle of the front
and rear wheels and effort necessary
to turn the steering wheel to help
enhance steering responsiveness. WARNING■
Limitations of the pre-collision system●
The driver is solely responsible for safe
driving. Always drive safely, taking
care to observe your surroundings.
Do not use the pre-collision system
instead of normal braking operations
under any circumstances. This system
will not prevent collisions or lessen col-
lision damage or injury in every situa-
tion. Do not overly rely on this system.
Failure to do so may lead to an acci-
dent, resulting in death or serious
injury.
●
Although this system is designed to
help avoid a collision or help reduce
the impact of the coll ision, its effective-
ness may change according to various
conditions, therefore the system may
not always be able to achieve the same
level of performance.
Read the following conditions care-
fully. Do not overly rely on this system
and always drive carefully.
• Conditions under which the system
may operate even if there is no possi-
bility of a collision:  P.219
• Conditions under which the system
may not operate properly:  P.220 ●
Do not attempt to test the operation of
the pre-collision system yourself.
Depending on the objects used for
testing (dummies, cardboard objects
imitating detectable objects, etc.), the
system may not operate properly, pos-
sibly leading to an accident. ■
Pre-collision braking ●
When the pre-collision braking func-
tion is operating, a large amount of
braking force will be applied. ●
If the vehicle is stopped by the opera-
tion of the pre-collision braking func-
tion, the pre-collision braking function
operation will be canceled after
approximately 2 seco nds. Depress the
brake pedal as necessary. ●
The pre-collision braking function may
not operate if certain operations are
performed by the driver. If the acceler-
ator pedal is being depressed strongly
or the steering wheel is being turned,
the system may determine that the
driver is taking evasive action and pos-
sibly prevent the pre-collision braking
function from operating. ●
In some situations, while the pre-colli-
sion braking function is operating,
operation of the function may be can-
celed if the accelerator pedal is
depressed strongly or the steering
wheel is turned and the system deter-
mines that the driver is taking evasive
action.
●
If the brake pedal is being depressed,
the system may determine that the
driver is taking evasive action and pos-
sibly delay the operat ion timing of the
pre-collision braking function.
■
When to disable the pre-collision sys-
tem
In the following situations, disable the
system, as it may not operate properly,
possibly leading to an accident resulting
in death or serious injury:
●
When the vehicle is being towed

218 4-5. Using the driving support systems
LS500_OM_(U)_1810 1 Early
2 Middle This is the default setting.
3 Late
■
Operational conditions
The pre-collision system is enabled and the system determines that the possibility of a frontal
collision with a detect ed object is high.
Each function is operational at the following speed ●
Pre-collision warning
●
Pre-collision brake assist Detectable objects Vehicle speed Relative speed between your
vehicle and object
Vehicles Approx. 7 to 110 mph (10 to
180 km/h) Approx. 7 to 110 mph (10 to
180 km/h)
Bicyclists and pedestrians Approx. 7 to 50 mph (10 to
80 km/h) Approx. 7 to 50 mph (10 to
80 km/h)
Detectable objects Vehicle speed Relative speed between your
vehicle and object
Vehicles Approx. 20 to 110 mph (30
to 180 km/h) Approx. 20 to 110 mph (30
to 180 km/h)
Bicyclists and pedestrians Approx. 20 to 50 mph (30
to 80 km/h) Approx. 20 to 50 mph (30
to 80 km/h)