
202 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) WARNING■
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 may
prevent the pre-collision braking func-
tion 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 operation timing of the
pre-collision braking function.
■
Active steering assist●
The steering wheel may turn automati-
cally when active steering assist is
operating.
●
As active steering assist operation will
be canceled when the system deter-
mines that a collision has been
avoided, operate the steering wheel as
necessary. ●
In the following situations, the system
may determine that th e driver is taking
evasive action. In this case, the active
steering assist may not operate or may
be canceled.
• If the accelerator pedal is being
depressed strongly or the steering
wheel is being operat ed. In this case
the system may determine that the
driver is taking evasive action and the
pre-collision braking may not operate.
• In some situations, while the active
steering assist is operating, operation
of the function may be canceled if the
accelerator pedal is depressed
strongly or the steering wheel is turned
and the system determines that the
driver is taking evasive action.
• When the active steering assist is
operating, if the stee ring wheel is held
firmly or is operated in the opposite
direction to that which the system is
generating torque, the function may be
canceled.
• If the brake pedal is depressed, the sys-
tem may determine that the driver is
taking evasive action and the active
steering assist operation may be
delayed.
■
Pre-collision seat belts with comfort
function
If the pre-collision se at belts have oper-
ated and the seat belts are locked in a
retracted position, immediately stop the
vehicle in a safe place, release and
retract the seat belts to unlock them and
then fasten them again.
Also, if a seat belt ca n be loosened, it can
be unlocked by slightly retracting it with-
out releasing it.
■
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

2034-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving ■
Enabling/disabling the pre-colli-
sion system
The pre-collision system can be
enabled/disabled on ( → P.76) of
the multi-information display. The system is automa tically enabled each
time the engine switch is turned to IGNI-
TION ON mode
If the system is disabled, the PCS warn-
ing light will turn on and a message will
be displayed on the multi-information
display.
If the pre-collision sy stem is disabled,
the pedestrian alert system will also be
disabled. At this time, the FCTA (Front
Cross Traffic Alert) ( → P.218) system
will also be disabled.
■
Enabling/Disabling the pedestrian
alert system
The pedestrian alert can be
enabled/disabled on ( → P.76) of
the multi-information display. At this
time, the FCTA (Front Cross Traffic
Alert) system will also be enabled/dis-
abled.WARNING●
When your vehicle is towing another
vehicle●
When transporting the vehicle via
truck, boat, train or similar means of
transportation●
When the vehicle is raised on a lift with
the engine running and the tires are
allowed to rotate freely●
When inspecting the vehicle using a
drum tester such as a chassis dyna-
mometer or speedometer tester, or
when using an on vehicle wheel bal-
ancer●
When a strong impact has been
applied to the front bumper, rear
bumper or front grille, due to an acci-
dent or other situation●
If the vehicle cannot be driven in a sta-
ble manner, such as when the vehicle
has been in an accident or is malfunc-
tioning●
When the vehicle is driven in a sporty
manner or off-road●
When the tires are not properly
inflated
●
When the tires are very worn
●
When tires of a size other than speci-
fied are installed
●
When tire chains are installed
●
When a compact spare tire or an
emergency tire puncture repair kit is
used
●
If equipment (snow plow, etc.) that may
obstruct a sensor is temporarily
installed to the vehicle Changing settings of the pre-col-
lision system

206 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) • When driving on a road where relative
location to vehicle ahead in an adjacent
lane may change, such as on a winding
road
• When rapidly closing on a vehicle ahead
• When the road surface is uneven or
undulating
• If the front of the vehicle is raised or low-
ered
• When approaching ob jects on the road-
side, such as guardrails, traffic signs, util-
ity poles, street light s, trees, walls, etc.
• When there is a vehicle, pedestrian, bicy-
clist, or object by the roadside at the
entrance of a curve
• When driving on a narrow path sur-
rounded by a structure, such as in a tun-
nel or on an iron bridge
• When there is a metal object (manhole
cover, steel plate, etc.), steps, dips, or a
protrusion on the ro ad surface or road-
side
• When a crossing pedestrian or bicyclist
approaches very close to the vehicle • When passing through a place with a low
structure above the road such as a low
ceiling, underpass, bridge girder, traffic
sign, etc.
• When passing under an object (billboard,
etc.) at the top of an uphill road
• When rapidly closing on an electric toll
gate barrier, parking area barrier, or
other barrier that opens and closes
• When using an automatic car wash
• When driving through or under objects
that may contact the vehicle, such as thick
grass, tree branches, or a banner
• When the vehicle is hit by water, snow,
dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When there are patterns or paint on the
road, a wall, or billboard that may be mis-
taken for a vehicle, pedestrian, or bicy-
clist
• When driving near an object that reflects
radio waves, such as a large truck or
guardrail

208 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) • If a vehicle ahead is irregularly shaped,
such as a tractor or side car
• If the sun or other light is shining directly
on a vehicle or guardrail ahead
• If a vehicle cuts in front of your vehicle or
emerges from beside a vehicle
• If a vehicle ahead makes an abrupt
maneuver (such as sudden swerving,
acceleration or deceleration)
• When suddenly cutting behind a preced-
ing vehicle
• When a vehicle ahead is not directly in
front of your vehicle
• When driving in incl ement weather such
as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, snow,
dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the sur-
rounding brightness changes suddenly,
such as at the entrance or exit of a tunnel
• When a very bright light, such as the sun
or the headlights of oncoming traffic,
shines directly in to the camera sensor
• When driving in a lo cation where there
are many objects which reflect radar,
such as a tunnel or parking garage
• When driving at night or in a tunnel with
the headlights off
• When the surrounding area is dim, such
as at dawn or dusk, or while at night or in
a tunnel
• 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 camera
sensor
• The vehicle is wobbling.
• The vehicle is being driven at extremely
high speeds.
• When driving on a hill
• If a sensor is misaligned
• 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)●
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

2094-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving • 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 pedestrians and bicyclists, such as
the following, may not be detected by the
sensors, preventing the system from
operating properly:
• Pedestrians and bicyclists shorter than
approximately 3.2 ft. (1 m) or taller than
approximately 6.5 ft. (2 m)
• Bicyclists riding on unusual bicycles
(bicycles for small children, tricycles,
folding bicycles, BMX bicycles, tandem
bicycles, etc.)
• Pedestrians and bicyclists who are wear-
ing white and look extremely bright
• Pedestrians and bicyclists which are not
illuminated by the headli ghts at night, in a
tunnel, etc.
• Pedestrians whose clothing appears to
be nearly the same co lor or brightness as
their surroundings
• Pedestrians and bicy clists near walls,
fences, guardrails, or large objects
• Pedestrians and bicyclists which are on a
metal object (manhole cover, steel plate,
etc.) on the road
• Pedestrians and bicyclists which are mov-
ing fast
• Pedestrians and bicy clists 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.) • Pedestrians and bicyclists wearing over-
sized clothing, such as a rain coat, long
skirt, etc., making their silhouette obscure
• Pedestrians and bicyclists who are carry-
ing large baggage, ho lding an umbrella,
etc., hiding part of their body
• Pedestrians and bicyclists behind an
object that hides part of their body
• Pedestrians and bicyclists who are bend-
ing forward or squatting
• Pedestrians who are pushing a stroller,
wheelchair, bicycle or other vehicle
• Groups of pedestrians/bicyclists which
are close together ●
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 gu ardrails (wire cable
guardrails, guardrails made of thin poles,
etc.)
• Guardrails which are not illuminated by
the headlights at nigh t, 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

210 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) reclined
• If the head-up display position is set
extremely high■
If the PCS warning light flashes or illumi-
nates and a warning message is dis-
played on the multi-information display
The pre-collision system may be temporar-
ily unavailable or there may be a malfunc-
tion in the system. ●
In the following situations, the warning
light will turn off, the message will disap-
pear and the system will become opera-
tional when normal operating conditions
return:
• When a sensor or the area around a sen-
sor is hot, such as in the sun
• When a sensor or the area around a sen-
sor is cold, such as in an extremely cold
environment
• When a sensor is dirty or covered with
snow, etc.
• When the part of the windshield in front
of the camera sensor is fogged up or cov-
ered with condensation or ice (Defog-
ging the windshield: → P.314)
• If the camera sensor is obstructed, such
as when the hood is open or a sticker is
attached to the windshield near the cam-
era sensor●
If the PCS warning ligh t continues to flash
or remains illuminated or the warning
message does not disappear even
though the vehicle has returned to nor-
mal, the system may be malfunctioning.
Have the vehicle inspected by your Lexus
dealer immediately.■
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. PCS (Pre-Collision System)
(vehicles with Lexus Safety
System+) The pre-collision system uses a
radar sensor and camera sensor to
detect vehicles and pedestrians in
front of your vehi cle. When the sys-
tem determines that the possibility
of a frontal collision with a vehicle
or pedestrian 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 determines that the possi-
bility of a frontal collision with a
vehicle or pedestrian is extremely
high, the brakes are automatically
applied to help avoi d 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.213)

2134-5. Using the driving support systems
LS500_OM_OM50F54U_(U) 4
Driving
■
Enabling/disabling the pre-colli-
sion system
The pre-collision system can be
enabled/disabled on ( → P.76) of
the multi-information display. The system is automatically enabled each
time the engine switch is turned to IGNI-
TION ON mode
If the system is disabled, the PCS warn-
ing light will turn on and a message will
be displayed on the multi-information
display. ■
Changing the pre-collision warn-
ing timing
The pre-collision warning timing can
be changed on ( → P.76) of the
multi-information display. The operation timing setting is retained
when the engine switch is turned off.
1 Far The warning will begin to operate earlier
than with the default timing.
2 Middle This is the default setting.
3 Near The warning will begi n to operate later
than with the default timing.
■
Operational conditions
The pre-collision system is enabled and the WARNING●
If the vehicle cannot be driven in a sta-
ble manner, such as when the vehicle
has been in an accident or is malfunc-
tioning●
When the vehicle is driven in a sporty
manner or off-road●
When the tires are not properly
inflated●
When the tires are very worn●
When tires of a size other than speci-
fied are installed●
When tire chains are installed●
When a compact spare tire or an
emergency tire puncture repair kit is
used●
If equipment (snow plow, etc.) that may
obstruct the radar sensor or camera
sensor is temporarily installed to the
vehicle
Changing settings of the pre-col-
lision system

216 4-5. Using the driving support systems
LS500_OM_OM50F54U_(U) road or a wall that may be mistaken for a
vehicle or pedestrian
• When driving near an object that reflects
radio waves, such as a large truck or
guardrail
• When driving near a TV tower, broad-
casting station, electric power plant, or
other location where strong radio waves
or electrical noise may be present■
Situations in which the system may not
operate properly●
In some situations such as the following, a
vehicle may not be detected by the radar
sensor and camera sensor, preventing
the system from operating properly:
• If an oncoming vehicle is approaching
your vehicle
• If a vehicle ahead is a motorcycle or bicy-
cle
• When approaching the side or front of a
vehicle
• If a preceding vehicle has a small rear
end, such as an unloaded truck
• If a preceding vehicle has a low rear end,
such as a low bed trailer
• If a vehicle ahead is carrying a load which
protrudes past its rear bumper
• If a vehicle ahead has extremely high
ground clearance
• If a vehicle ahead is irregularly shaped,
such as a tractor or side car
• If the sun or other light is shining directly
on a vehicle ahead
• If a vehicle cuts in front of your vehicle or emerges from beside a vehicle
• If a vehicle ahead makes an abrupt
maneuver (such as sudden swerving,
acceleration or deceleration)
• When suddenly cutting behind a preced-
ing vehicle
• When a vehicle ahead is not directly in
front of your vehicle
• When driving in incl ement weather such
as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, snow,
dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the sur-
rounding brightness changes suddenly,
such as at the entrance or exit of a tunnel
• When a very bright light, such as the sun
or the headlights of oncoming traffic,
shines directly into the camera sensor
• When the surrounding area is dim, such
as at dawn or dusk, or while at night or in
a tunnel
• 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 camera
sensor