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1934-5. Using the driving support systems
4
Driving
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.195
• Conditions under which the system may not operate properly: P.197
●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 seconds.
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
●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
Page 194 of 436

1944-5. Using the driving support systems
■Enabling/disabling the pre-colli-
sion system
The pre-collision system can be
enabled/disabled on ( P.84) of
the multi-information display.
The system is automatically enabled each
time the engine switch is
turned to IGNITION 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.84) 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.
2Middle
This is the default setting.
WARNING
●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 is applied to the
front bumper or front grille, due to an
accident or other reasons
●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
Page 195 of 436

1954-5. Using the driving support systems
4
Driving
3Near
The warning will begin to operate later
than with the default timing.
■Operational conditions
The pre-collision system is enabled and the
system determines that the possibility of a
frontal collision with a vehicle or pedestrian
is high.
Each function is operational at the following
speeds:
●Pre-collision warning:
• Vehicle speed is be tween approximately
7 and 110 mph (10 and 180 km/h). (For
detecting a pedestrian, vehicle speed is
between approximately 7 and 50 mph
[10 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 7 mph (10 km/h) or more.
●Pre-collision brake assist:
• Vehicle speed is be tween approximately
20 and 110 mph (30 and 180 km/h). (For
detecting a pedestrian, vehicle speed is
between approximately 20 and 50 mph
[30 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 20 mph (30 km/h) or
more.
●Pre-collision braking:
• Vehicle speed is be tween approximately
7 and 110 mph (10 and 180 km/h). (For
detecting a pedestrian, vehicle speed is
between approximately 7 and 50 mph
[10 and 80 km/h].)
• The relative speed between your vehicle
and the vehicle or pedestrian ahead is
approximately 7 mph (10 km/h) or more.
The system may not operate in the following
situations:
●If a 12-volt battery terminal has been dis-
connected and reconnected and then the
vehicle has not been driven for a certain
amount of time
●If the shift position is in R
●If VSC is disabled (only the pre-collision
warning function will be operational)
■Pedestrian detection function
The pre-collision system detects pedestri-
ans based on the size, profile, and motion of
a detected object. However, a pedestrian
may not be detected depending on the sur-
rounding brightness and the motion, pos-
ture, and angle of the detected object,
preventing the system from operating prop-
erly. ( P.197)
■Cancelation of the pre-collision braking
If either of the following occur while the
pre-collision braking function is operating, it
will be canceled:
●The accelerator pedal is depressed
strongly.
●The steering wheel is turned sharply or
abruptly.
■Conditions under which the system may
operate even if there is no possibility of a
collision
●In some situations su ch as the following,
the system may determine that there is a
possibility of a frontal collision and oper-
ate.
• When passing a vehicle or pedestrian
• When changing lanes while overtaking a
preceding vehicle
• When overtaking a preceding vehicle
that is changing lanes
• When overtaking a preceding vehicle that is making a left/right turn
• When passing a vehicle in an oncoming
Page 196 of 436

1964-5. Using the driving support systems
lane that is stopped to make a right/left
turn
• 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
• If the front of the vehicle is raised or low- ered, such as when the road surface is
uneven or undulating
• When approaching objects on the road- side, such as guardr ails, utility poles,
trees, or walls
• When there is a vehicle, pedestrian, 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, or a protru-
sion on the road surface or roadside
• When a crossing pedestrian approaches very close to the vehicle • When passing through a place with a low
structure above the road (low ceiling,
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
Page 197 of 436

1974-5. Using the driving support systems
4
Driving
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
Page 198 of 436

1984-5. Using the driving support systems
• The vehicle is wobbling.
• The vehicle is being driven at extremely high speeds.
• When driving on a hill
• If the radar sensor or camera sensor is misaligned
●In some situations such as the following,
sufficient braking force may not be
obtained, preventing the system 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
●Some pedestrians such as the following
may not be detected by the radar sensor
and camera sensor, preventing the sys-
tem from operating properly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or tall er than approximately
6.5 ft. (2 m)
• Pedestrians wearing oversized clothing (a rain coat, long skirt, etc.), making their
silhouette obscure
• Pedestrians who are carrying large bag- gage, holding an umbrella, etc., hiding
part of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller, wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close
together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to
be nearly the same co lor or brightness as
their surroundings
• Pedestrians near walls , fences, guardrails,
or large objects
• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the
road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly • Pedestrians running out from behind a
vehicle or a large object
• Pedestrians who are extremely close to
the side of the vehicle (outside rear view
mirror, etc.)
■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 the radar sensor or camera sensor
or the area around either sensor is hot,
such as in the sun
• When the radar sensor or camera sensor
or the area around either sensor is cold,
such as in an extremely cold environment
• When a front 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.253)
• 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 light 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.236), 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.
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1994-5. Using the driving support systems
4
Driving
■Lane departure alert function
When the system determines that the
vehicle might depart from its lane, a
warning is displayed on the multi-infor-
mation display, and either the warning
buzzer sounds to alert the driver.
When the warning buzzer sounds, check
the surrounding road situation and care- fully operate the steering wheel to move
the vehicle back to the center of the lane.
■Steering assist function
When the system determines that the
vehicle might depart from its lane, the
system provides assistance as neces-
sary by operating the steering wheel in
small amounts for a short period of
time to keep the vehicle in its lane.
If the system detects 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-informat ion display and the
warning buzzer sounds.
LKA (Lane-Keeping Assist)
When driving on highways and
freeways with white or yellow lines,
this function alerts the driver when
the vehicle might depart from its
lane and provides assistance by
operating the steering wheel to
keep the vehicle in its lane. Further-
more, the system also provides
steering assistance when dynamic
radar cruise control with full-speed
range is operating to keep the vehi-
cle in its lane.
The LKA system recognizes visible
white or yellow lines with the cam-
era sensor on the upper portion of
the front windshield.
Functions included in LKA sys-
tem
Page 200 of 436
2004-5. Using the driving support systems
■Vehicle sway warning function
When the vehicle is swaying or
appears as if it may depart from its lane
multiple times, the warning buzzer
sounds and a message is displayed on
the multi-information display to alert
the driver.
■Lane centering function
This function is linked with radar cruise
control and provides the required
assistance by operating the steering
wheel to keep the vehicle in its current
lane.
When radar cruise cont rol is not operating,
the lane centering function does not oper-
ate.
If the system detects 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-informat ion display and the
warning buzzer sounds.