2021 LEXUS RC350 Owners Manual

1774-5. 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 conditio ns. It is still neces-
sary 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 has limited capability to
prevent or avoid a collision with a vehicle
traveling ahead. Therefore, if there is
ever any danger, the driver must take
immediate and direct control of the vehi-
cle 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 acci-
dent 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 th e radar sensor or
camera sensor
●In traffic conditions that require fre-
quent repeated acceleration and
deceleration
●During emergency towing
●When an approach warning buzzer is
heard often

1784-5. Using the driving support systems
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 distance will close in when traveling on downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle distance
can also be set by operating the vehicle-to-vehicle distance switch.
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 will resume follow-up cruising.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed
The system accelerates until the set speed is re ached. The system then returns to constant
speed cruising.
Driving in vehicle-to-vehicle distance control mode
A
B
C

1794-5. Using the driving support systems
4
Driving
1Press the “ON/OFF” button to acti-
vate the cruise control.
Dynamic radar cruise control indicator will
come on and a message will be displayed
on the multi-information display.
Press the button again to deactivate the
cruise control.
If the “ON/OFF” button is pressed and
held for 1.5 seconds or more, the system
turns on in constant speed control mode.
( P.182)
2 Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 30 mph [50 km/h])
and push the lever down to set the
speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the lever
is released becomes the set speed.
If the lever is operated while the vehicle
speed is below approximately 30 mph (50
km/h) and a preceding vehicle is present,
the set speed will be adjusted to approxi- mately 30 mph (50 km/h).
To change the set speed, operate the
lever until the desired set speed is dis-
played.
1
Increases the speed (Except when
the vehicle has been stopped by
system control in vehicle-to-vehi-
cle distance control mode)
2 Decreases the speed
Fine adjustment: Momentarily move
the lever in the desired direction.
Large adjustment: Hold the lever up or
down to change the speed, and release
when the desired speed is reached.
In the vehicle-to-vehicle distance con-
trol mode, the set speed will be
increased or decreased as follows:
■For the U.S. mainland and Hawaii
Fine adjustment: By 1 mph (1.6 km/h)*1 or 1
Setting the vehicle speed (vehi-
cle-to-vehicle distance control
mode)
Adjusting the set speed

1804-5. Using the driving support systems
km/h (0.6 mph)*2 each time the lever is
operated
Large adjustment: Increases or decreases
in 1 mph (1.6 km/h)
*1 or 1 km/h (0.6 mph)*2
increments for as long as the lever is held
■For Canada, Guam and Puerto
Rico
Fine adjustment: By 1 mph (1.6 km/h)*1 or 1
km/h (0.6 mph)
*2 each time the lever is
operated
Large adjustment: Increases or decreases
in 5 mph (8 km/h)
*1 or 5 km/h (3.1 mph)*2
increments for as long as the lever is held
In the constant speed control mode
(  P.182), the set speed will be
increased or decreased as follows:
Fine adjustment: By 1 mph (1.6 km/h)*1 or
1.6 km/h (1 mph)
*2 each time the lever is
operated
Large adjustment: The speed will continue
to change while the lever is held.
*1: When the set speed is shown in “MPH”
*2: When the set speed is shown in “km/h”
Pressing the switch changes the vehi-
cle-to-vehicle distance as follows: 1
Long
2 Medium
3 Short
The vehicle-to-vehicle distance is set auto-
matically to long mode when the engine
switch is turned to IGNITION ON mode.
If a vehicle is running ahead of you, the pre-
ceding vehicle mark will also be dis-
played.
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.
Changing the vehicle-to-vehicle
distance (vehicle-to-vehicle dis-
tance control mode)
Vehicle-to-vehicle distance set-
tings (vehicle-to-vehicle dis-
tance control mode)
Distance
optionsVehicle-to-vehicle dis- tance
LongApproximately 160 ft. (50
m)
A

1814-5. Using the driving support systems
4
Driving
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.
However, when a vehicle ahead is not
detected, cruise control does not resume
when the vehicle speed is approximately
25 mph (40 km/h) or less.
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.
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.
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)
Distance optionsVehicle-to-vehicle dis- tanceCanceling and resuming the
speed control
Approach warning (vehi-
cle-to-vehicle distance control
mode)

1824-5. Using the driving support systems
■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
When constant speed control mode is
selected, your vehicle will maintain a
set speed without controlling the vehi-
cle-to-vehicle distance. Select this
mode only when vehicle-to-vehicle dis-
tance control mode does not function
correctly due to a dirty radar sensor,
etc.
1 With the cruise control off, press
and hold the “ON/ OFF” button for
1.5 seconds or more.
Immediately after the “ON/OFF” button is
pressed, the dynamic radar cruise control indicator will come on. Afterwards, it
switches to the cruise control indicator.
Switching to constant speed control mode
is only possible when operating the lever
with the cruise control off.
2
Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 30 mph [50 km/h])
and push the lever down to set the
speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the lever
is released beco mes the set speed.
Adjusting the speed setting: P.179
Canceling and resuming the speed setting:
 P.181
■Dynamic radar cruise control with
full-speed range can be set when
●The shift lever is in D.
●Range 4 or higher of D has been selected
by using the paddle shift switch.
●Vehicle speed is at or above approxi-
Selecting constant speed con-
trol mode

1834-5. Using the driving support systems
4
Driving
mately 30 mph (50 km/h).
However, when a preceding vehicle is
detected, the dynamic radar cruise con-
trol with full-speed range can be set even
if the vehicle speed is below approxi-
mately 30 mph (50 km/h).
■Accelerating after setting the vehicle
speed
The vehicle can accelerate by operating the
accelerator pedal. After accelerating, the
set speed resumes. However, during vehi-
cle-to-vehicle distance control mode, the
vehicle speed may decrease below the set
speed in order to maintain the distance to
the preceding vehicle.
■When the vehicle stops while follow-up
cruising
●Pushing the lever up while the vehicle
ahead stops will resume follow-up cruis-
ing if the vehicle ahead starts off within
approximately 3 seconds after the lever
is pushed up.
●If the vehicle ahead starts off within 3 sec-
onds after your vehicle stops, follow-up
cruising will be resumed.
■Automatic cancelation of vehi-
cle-to-vehicle distance control mode
Vehicle-to-vehicle dist ance control mode is
automatically canceled in the following situ-
ations:
●Actual vehicle speed falls at or below
approximately 25 mph (40 km/h) when
there are no vehicles ahead.
●The preceding vehicle leaves the lane
when your vehicle is following at a vehicle
speed at or below approximately 25 mph
(40 km/h). Otherwise, the sensor can
not properly detect the vehicle. (“Radar
Cruise Control Not Available No Pre-
ceding Vehicles” is displayed on the
multi-information display)
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●When snow mode is set.
●The sensor cannot detect correctly
because it is covered in some way.
●Pre-collision braking is activated.
●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 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●Pre-collision braking is activated.
If constant speed control mode is automati-
cally canceled for any other reason, there
may be a malfunction in the system. Con-
tact your Lexus dealer.
■Brake system operation sound
If the brakes are app lied automatically while
the vehicle is in vehicle-to-vehicle distance
control mode, a brake system operation
sound may be heard. This does not indicate
a malfunction.
■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

1844-5. Using the driving support systems
multi-information display, read the message
and follow the instructions.
■When the sensor may not be correctly
detecting the vehicle ahead
In the case of the following 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.181) 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.)
●Motorcycles travelin g in the same lane
●When water or snow thrown up by the
surrounding vehicles hinders the detect-
ing of the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
●Preceding vehicle has an extremely high
ground clearance
■Conditions under which the vehi-
cle-to-vehicle distance control mode
may not function correctly
In the case of the following conditions,
operate the brake pedal (or accelerator
pedal, depending on the situation) as nec-
essary.
As the sensor may not be able to correctly
detect vehicles ahead, the system may not
operate properly.
●When the road curves or when the lanes
are narrow
●When steering wheel operation or your
position in the lane is unstable
●When the vehicle ahead of you deceler-
ates suddenly
●When driving on a road surrounded by a
structure, such as in a tunnel or on a
bridge
●While the vehicle speed is decreasing to
the set speed after the vehicle acceler-
ates by depressing the accelerator pedal