2021 Lexus IS350 warning

1884-5. Using the driving support systems
●The steering control of the function is
overridden by the driver’s steering wheel
operation.
●Do not attempt to test the operation of
the steering assist function.
■Lane departure alert function
●The warning buzzer may be difficult to
hear due to external noise, audio play-
back, etc. Also, it may be difficult to feel
steering wheel vibrations due to the road
conditions, etc.
●If the edge of the course* is not clear or
straight, the lane departure alert function
may not operate.
●Vehicle with BSM: It may not be possible
for the system to determine if there is a
danger of a collision with a vehicle in an
adjacent lane.
●Do not attempt to test the operation of
the lane departure alert function.
*: Boundary between asphalt and the side
of the road, such as grass, soil, or a curb
■Hands off steering wheel warning
In the following situations, a warning mes-
sage urging the driver to hold the steering
wheel and the symbol shown in the illustra-
tion are displayed on the multi-information
display to warn the driver. The warning
stops when the system determines that the
driver holds the steering wheel. Always
keep your hands on the steering wheel
when using this system, regardless of warn-
ings.
●When the system determines the driver is
not holding the steeri ng wheel while the
lane centering function is operating.
If the driver continue s to keep their hands
off of the steering wheel, the buzzer
sounds, the driver is warned and the func- tion is temporarily ca
nceled. This warning
also operates in the same way when the
driver continuously operates the steering
wheel only a small amount.
The buzzer also sounds even if the alert
type is set to .
●When the system determines that the
vehicle may deviate from the lane while
driving around a curve while the lane
centering function is operating.
Depending on the vehicle condition and
road conditions, the warning may not
operate. Also, if the sy stem determines that
the vehicle is driving around a curve, warn-
ings will occur earlier than during
straight-lane driving.
●When the system determines that the
driver is driving with out holding the steer-
ing wheel while the st eering wheel assist
of the steering assist function is operat-
ing.
If the driver continues to keep their hands
off of the steering wheel and the steering
wheel assist is operating, the buzzer
sounds and the driver is warned. Each time
the buzzer sounds, the continuing time of
the buzzer becomes longer.
The buzzer also sounds even if the alert
type is set to .
■Vehicle sway warning function
When the system determines that the vehi-
cle is swaying while the vehicle sway warn-
ing function is operating, a buzzer sounds
and a warning message urging the driver to
rest and the symbol sh own in the illustration
are simultaneously displayed on the
multi-information display.

1894-5. Using the driving support systems
4
Driving
Depending on the vehicle and road condi-
tions, the warning may not operate.
■Warning message
If the following warning message is dis-
played on the multi-information display and
the LTA indicator illumin ates in orange, fol-
low the appropriate troubleshooting proce-
dure. Also, if a different warning message is
displayed, follow the instructions displayed
on the screen.
●“LTA Malfunction Visit Your Dealer”
The system may not be operating properly.
Have the vehicle inspected by your Lexus
dealer.
●“LTA Unavailable”
The system is temporarily canceled due to
a malfunction in a se nsor other than the
front camera. Turn the LTA system off, wait
for a little while, and then turn the LTA sys-
tem back on.
●“LTA Unavailable at Current Speed”
The function cannot be used as the vehicle
speed exceeds the LTA operation range.
Drive slower.
■Customization
Function settings can be changed. (Cus-
tomizable features: P.394)
*: If equipped
The RSA system recognizes specific
road signs using the front camera
and/or navigation system (when speed
limit information is available) to provide
information to the driver via the display.
If the system judges that the vehicle is
being driven over the speed limit, per-
forming prohibited actions, etc.
according to the recognized road
signs, it notifies the driver through a
visual notification and notification
buzzer.
When the front camera recognizes a
RSA (Road Sign Assist)*
Summary of function
WARNING
■Before using the RSA
Do not rely solely upon the RSA system.
RSA is a system which supports the
driver by providing information, but it is
not a replacement for a driver’s own
vision and awareness. Drive safely by
always paying careful attention to the
traffic rules.
Indication on the multi-informa-
tion display

1924-5. Using the driving support systems
Vehicle-to-vehicle distance switch
Multi-information display
Set speed
IndicatorsCruise control switch
Dynamic radar cruise con-
trol with full-speed range
In vehicle-to-vehicle distance con-
trol mode, the vehicle automati-
cally accelerates, decelerates and
stops to match the speed changes
of the preceding vehicle even if the
accelerator pedal is not depressed.
In constant speed control mode,
the vehicle runs at a fixed speed.
Use the dynamic radar cruise con-
trol with full-speed range on free-
ways and highways.

Vehicle-to-vehicle distance con-
trol mode ( P.194)
 Constant speed control mode
( P.199)
System Components
A
B
C
D
WARNING
■Before using dynamic radar cruise
control with full-speed range
●Driving safely is th e sole responsibility
of the driver. Do not rely solely on the
system, and drive safely by always pay-
ing careful attention to your surround-
ings.
●The dynamic radar cruise control with
full-speed range provides driving
assistance to reduce the driver’s bur-
den. However, there are limitations to
the assistance provided.
Read the following conditions care-
fully. Do not overly rely on this system
and always drive carefully.
• When the sensor ma y not be correctly
detecting the vehicle ahead:
P.200
• Conditions under which the vehi- cle-to-vehicle distance control mode
may not function correctly:
P.201
●Set the speed appropriately depend-
ing on the speed limit, traffic flow, road
conditions, weather conditions, etc.
The driver is responsible for checking
the set speed.
●Even when the system is functioning
normally, the condition of the preced-
ing vehicle as detected by the system
may differ from the condition
observed by the driver. Therefore, the
driver must always remain alert, assess
the danger of each situation and drive
safely. Relying solely on this system or
assuming the system ensures safety
while driving can lead to an accident,
resulting in death or serious injury.
●Switch the dynamic radar cruise con-
trol with full-speed range setting to off,
using the “ON/OFF” button when not
in use.
E

1934-5. Using the driving support systems
4
Driving
WARNING
■Cautions regarding the driving assist
systems
Observe the following precautions, as
there are limitations to the assistance
provided by the system. Failure to do so
may cause an accident resulting in death
or serious injury.
●Assisting the driver to measure follow-
ing distance
The dynamic radar cruise control with
full-speed range is only intended to help
the driver in determining the following
distance between the driver’s own vehi-
cle and a designated vehicle traveling
ahead. It is not a me chanism that allows
careless or inattentive driving, and it is
not a system that can assist the driver in
low-visibility conditions.
It is still necessary for driver to pay close
attention to the vehicle’s surroundings.
●Assisting the driver to judge proper
following distance
The dynamic radar cruise control with
full-speed range determines whether the
following distance be tween the driver’s
own vehicle and a designated vehicle
traveling ahead is within a set range. It is
not capable of making any other type of
judgement. Therefore, it is absolutely
necessary for the driver to remain vigi-
lant and to determine whether or not
there is a possibility of danger in any
given situation.
●Assisting the driver to operate the
vehicle
The dynamic radar cruise control with
full-speed range does not include func-
tions which will prevent or avoid colli-
sions with vehicles ahead of your vehicle.
Therefore, if there is ever any possibility
of danger, the driver must take immedi-
ate and direct control of the vehicle and
act appropriately in order to ensure the
safety of all involved.
■Situations unsuitable for dynamic
radar cruise control with full-speed
range
Do not use dynamic radar cruise control
with full-speed range in any of the follow-
ing situations. Doing so may result in
inappropriate speed control and could
cause an accident resulting in death or
serious injury.
●Roads where there are pedestrians,
cyclists, etc.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as those cov-
ered with rain, ice or snow
●On steep downhills, or where there
are sudden changes between sharp up
and down gradients
Vehicle speed may exceed the set speed
when driving down a steep hill.
●At entrances to freeways and highways
●When weather conditions are bad
enough that they may prevent the sen-
sors from detectin g correctly (fog,
snow, sandstorm, heavy rain, etc.)
●When there is rain, snow, etc. on the
front surface of the radar or front cam-
era
●In traffic conditions that require fre-
quent repeated acceleration and
deceleration
●During emergency towing
●When an approach warning buzzer is
heard often

1944-5. Using the driving support systems
This mode employs a radar to detect the presence of vehicles up to approximately
328 ft. (100 m) ahead, determines the cu rrent vehicle-to-vehicle following dis-
tance, and operates to maintain a suitab le following distance from the vehicle
ahead. The desired vehicle-to-vehicle distance can also be set by operating the
vehicle-to-vehicle distance switch.
When driving on downhill slopes, the vehicl e-to-vehicle distance may become shorter.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears
When 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 system 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 decelerate 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, pushing the cruise control lever up or
depressing the accelerator pedal (start-off operation) will resume follow-up cruising. If the
start-off operation is not performed, system control continues to keep your vehicle
stopped.
When the turn signal lever is operated and yo ur vehicle moves to an overtaking lane while
driving at 50 mph (80 km/h) or more, the vehicle will accelerate to help to overtake a
passing vehicle.
The system’s identification of what is an over taking lane may be determined solely based on
Driving in vehicle-to-vehicle distance control mode
A
B

1974-5. Using the driving support systems
4
Driving
Select a distance from the table below.
Note that the distances shown corre-
spond to a vehicle speed of 50 mph
(80 km/h). Vehicle-to-vehicle distance
increases/decreases in accordance
with vehicle speed. When the vehicle is
stopped by system control, the vehicle
stops at a certain vehicle-to-vehicle
distance depending on the situation.
After the vehicle ahead of you starts
off, push the lever up.
Your vehicle will also resume follow-up
cruising if the accelerator pedal is
depressed after the vehicle ahead of
you starts off.1
Pulling the lever toward you can-
cels the speed control.
The speed control is also canceled when
the brake pedal is depressed. (When the
vehicle has been stopped by system con-
trol, depressing the brake pedal does not
cancel the setting.)
2Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
Vehicle-to-vehicle distance set-
tings (vehicle-to-vehicle dis-
tance control mode)
Distance optionsVehicle-to-vehicle dis- tance
LongApproximately 160 ft. (50 m)
MediumApproximately 130 ft. (40 m)
ShortApproximately 100 ft. (30 m)
Resuming follow-up cruising
when the vehicle has been
stopped by system control (vehi-
cle-to-vehicle distance control
mode)
Canceling and resuming the
speed control
Approach warning (vehi-
cle-to-vehicle distance control
mode)

1984-5. Using the driving support systems
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehi-
cle-to-vehicle distance.
■Warnings may not occur when
In the following instances, warnings
may not occur even when the vehi-
cle-to-vehicle distance is small.
 When the speed of the preceding
vehicle matches or exceeds your
vehicle speed
 When the preceding vehicle is trav-
eling at an extremely slow speed
 Immediately after the cruise control
speed was set
 When depressing the accelerator
pedal
While driving in vehicle-to-vehicle dis-
tance control mode, this function will
reduce the vehicle speed, if it is deter-
mined to be necessary.
■Function operation
When the steering wheel begins to be
turned, the vehicle speed will begin
being reduced. When the steering wheel is returned to the center posi-
tion, the vehicle speed reduction will
end.
Depending on the situation, the vehicle
speed will then return to the vehi-
cle-to-vehicle distance control mode
set speed.
In situations where vehicle-to-vehicle
distance control needs to operate,
such as when a preceding vehicle cuts
in front of your vehicle, the curve speed
reduction function will be canceled.
■Operation display
Displayed when the vehicle speed is
being reduced.
When the vehicle speed reduction ends,
the display will disappear.
■Changing the settings of the curve
speed reduction function
The curve speed reduction function
can be enabled/disabled and the vehi-
cle speed reduction strength can be
adjusted.
Press the or meter control
switch to select . Press or
to select “Curve Speed Reduction” and
then press .
The setting will chan ge each time the
Curve speed reduction function

2004-5. Using the driving support systems
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●The sensor cannot detect correctly
because it is covered in some way.
●When the brake control or output restric-
tion control of a driving support system
operates.
(For example: Pre-Collision System,
Drive-Start Control)
●The parking brake is operated.
●The vehicle is stopped by system control
on a steep incline.
●The following are detected when the
vehicle has been stopped by system con-
trol:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes.
If vehicle-to-vehicle distance control mode
is automatically canceled for any reasons
other than the above, there may be a mal-
function in the system . Contact your Lexus
dealer.
■Automatic cancelation of constant
speed control mode
Constant speed control mode is automati-
cally canceled in the following situations:
●Actual vehicle speed is more than
approximately 10 mph (16 km/h) below
the set vehicle speed.
●Actual vehicle speed falls below approxi-
mately 20 mph (30 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●When the brake control or output restric-
tion control of a driving support system
operates.
(For example: Pre-Collision System,
Drive-Start Control)
●The parking brake is operated.
If constant speed cont rol mode is automati-
cally canceled for any reasons other than the above, there may be a malfunction in the
system. Contact your Lexus dealer.
■Situations in which the curve speed
reduction function may not operate
In situations such as the following, the curve
speed reduction function may not operate:
●When the vehicle is being driven around
a gentle curve
●When the accelerato r pedal is being
depressed
●When the vehicle is being driven around
an extremely short curve
■Brake operation
A brake operation sound may be heard and
the brake pedal response may change, but
these are not malfunctions.
■Warning messages and buzzers for
dynamic radar cruise control with
full-speed range
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution while driv-
ing. If a warning messa ge is shown on the
multi-information displa y, read the message
and follow the instructions. ( P.168, 346)
■When the sensor may not be correctly
detecting the vehicle ahead
In the case of the fo llowing and depending
on the conditions, operate the brake pedal
when deceleration of the system is insuffi-
cient or operate the accelerator pedal
when acceleration is required.
As the sensor may not be able to correctly
detect these types of vehicles, the approach
warning ( P.197) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same
lane
●Vehicles with small rear ends (trailers
with no load on board, etc.)