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2174-5. Using the driving support systems
4
Driving
■Operation switchesVehicle-to-vehicle distance switch
“+RES” switch
Cruise control main switch
Cancel switch
“-SET” switch
WARNING
■Before using dynamic radar cruise
control with full-speed range
●Driving safely is the 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 pr ovides driving
assistance to reduce the driver’s bur-
den. However, there are limitations to
the assistance provided.
Read the following co nditions carefully.
Do not overly rely on this system and
always drive carefully.
• When the sensor ma y not be correctly
detecting the vehicle ahead: P.224
• Conditions under which the vehicle- to-vehicle distance control mode may
not function correctly: P.225
A
B
C
D
E
●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 cruise control main switch
when not in use.
■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 mechanism 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.
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2184-5. Using the driving support systems
WARNING
●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 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 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
Page 219 of 476

2194-5. Using the driving support systems
4
Driving
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 sy stem 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, pressing the “+RES” switch or depressing
the accelerator pedal (start-off operation) will resume follow-up cruising. If the start-off
operation is not performed, system contro l continues to keep your vehicle stopped.
When the turn signal lever is operated and your vehicle moves to a left lane while driving at
50 mph (80 km/h) or more, the vehicle will quickly accelerate to help to overtake a pass-
ing vehicle.
Example of acceleration
Driving in vehicle-to-vehicle distance control mode
A
B
C
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2204-5. Using the driving support systems
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.
1 Press the cruise control main switch
to activate the cruise control.
Dynamic radar cruise control indicator will
come on and a message will be displayed
on the multi-information display. Press the
switch again to deactivate the cruise con-
trol.
If the cruise control ma in switch is pressed
and held for 1.5 seconds or more, the sys-
tem turns on in constant speed control
mode. ( P.223)
2 Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 20 mph [30 km/h])
and press the “-SET” switch to set
the speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the switch is released becomes the set speed.
To change the set speed, press the
“+RES” or “-SET” switch until the
desired set speed is displayed.
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: Press the switch.
Large adjustment: Press and hold the
switch to change the speed, and
release when the desired speed is
reached.
Setting the vehicle speed (vehi-
cle-to-vehicle distance control
mode)
Adjusting the set speed
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2214-5. Using the driving support systems
4
Driving
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
km/h (0.6mph)
*2 each time the switch is
pressed
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 switch is held
Except for the U.S. mainland and
Hawaii
Fine adjustment: By 1 mph (1.6 km/h)*1 or 1
km/h (0.6mph)
*2 each time the switch is
pressed
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 switch is held
In the constant speed control mode
( P.223), the set speed will be
increased or decreased as follows:
Fine adjustment: By 1 mph (1.6 km/h)*1 or 1
km/h (0.6 mph)
*2 each time the switch is
pressed
Large adjustment: The speed will continue
to change while the switch 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 power
switch is turned to ON.
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
distance
LongApproximately 160 ft. (50 m)
A
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2224-5. Using the driving support systems
After the vehicle ahead of you starts
off, press the “+RES” switch.
Your vehicle will also resume follow-up
cruising if the accelerator pedal is
depressed after the vehicle ahead of
you starts off.1
Pressing the cancel switch cancels
the speed control.The speed control is also canceled when
the brake pedal is depressed.
(When the vehicle has been stopped by
system control, depressing the brake pedal
does not cancel the setting.)
2Pressing the “+RES” switch
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.
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 distanceCanceling and resuming the
speed control
Approach warning (vehicle-to-
vehicle distance control mode)
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2234-5. Using the driving support systems
4
Driving
■Warnings may not occur when
In the following instances, warnings
may not occur even when the vehicle-
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, etc.
1 With the cruise control off, press
and hold the cruise control main
switch for 1.5 seconds or more.
Immediately after the switch 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 switch
with the cruise control off.
2 Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 20 mph [30 km/h])
and press the “-SET” switch to set
the speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the
switch is released becomes the set speed.
Adjusting the speed setting: P.220
Canceling and resuming the speed setting:
P.222
■Dynamic radar cruise control with full-
speed range can be set when
●The shift lever is in D.
●The desired set spee d can be set when
the vehicle speed is approximately 20
mph (30 km/h) or more. (However, when
the vehicle speed is set while driving at
Selecting constant speed con-
trol mode
Page 224 of 476
![LEXUS UX250H 2019 Owners Manual 2244-5. Using the driving support systems
below approximately 20 mph [30 km/h],
the set speed will be set to approximately
20 mph [30 km/h].)
■Accelerating after setting the vehicle
speed
The veh LEXUS UX250H 2019 Owners Manual 2244-5. Using the driving support systems
below approximately 20 mph [30 km/h],
the set speed will be set to approximately
20 mph [30 km/h].)
■Accelerating after setting the vehicle
speed
The veh](/manual-img/36/58039/w960_58039-223.png)
2244-5. Using the driving support systems
below approximately 20 mph [30 km/h],
the set speed will be set to approximately
20 mph [30 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
●Pressing the “+RES” switch while the
vehicle ahead stops w ill resume follow-up
cruising if the vehicle ahead starts off
within approximately 3 seconds after the
switch is pressed.
●If the vehicle ahead starts off within 3 sec-
onds after your vehicle stops, follow-up
cruising will be resumed.
■Automatic cancelation of vehicle-to-
vehicle distance control mode
Vehicle-to-vehicle dist ance control mode is
automatically canceled in the following situ-
ations.
●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.
●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 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.
●Pre-collision braking is activated.
If constant speed control mode is automati-
cally canceled for any reasons other than
the above, there may be a malfunction in the
system. Contact your Lexus dealer.
■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.196, 395)
■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.222) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same