2019 LEXUS RX450H cruise control

2494-2. Driving procedures
4
Driving
RX450h_RX450hL_U
■When the “-” paddle shift switch is operated with the shift lever in the D position (vehi-
cles with paddle shift switches)
The shift range is downshifted to a range that enables engine braking force that is suit-
able to driving conditions.
■Automatic deactivation of shif t range selection in the D position (vehicles with paddle
shift switches)
Shift range selection in the D position will be deactivated in the following situations:
●When the vehicle comes to a stop
●If the accelerator pedal is depressed fo r more than a certain period of time
●When the shift lever is shifted to a position other than D
■S mode
●When the shift range is S4 or lower, holding the shift lever toward “+” sets the shift
range to S6.
●Automatically selects a higher shift range before the engine speed becomes too high.
■Downshifting restriction warning buzzer
To help ensure safety and driving performance, downshifti ng operation may sometimes
be restricted. In some circum stances, downshifting may not be possible even when the
shift lever or paddle shift sw itch (if equipped) is operated . (A buzzer will sound twice.)
■When driving with dynamic radar cruise control with full-speed range activated
Even when performing the following actions with the intent of enabling engine braking,
engine braking will not occur because dynamic radar cruise control with full-speed
range will not be canceled.
●Vehicles without paddle shift switches: While driving in S mode, downshifting to 5 or 4.
(  P. 306)
●Vehicles with paddle shift sw itches: While driving in D or S mode, downshifting to 5 or
4. ( P. 306)
●When switching the driving mode to spor t mode while driving in the D position
(  P. 379)
■Restraining sudden start (Drive-Start Control)
When the following unusual operation is performed, the hybrid system output may be
restrained.
●When the shift lever is shifted from R to D, D to R, N to R, P to D, or P to R (D includes S)
with the accelerator pedal depressed, a wa rning message appears on the multi-infor-
mation display. If a warning message is shown on the multi- information display, read the
message and follow the instructions.
●When the accelerator pedal is depressed too while the vehicle is in reverse.
■Shift lock system
The shift lock system is a system to prevent ac cidental operation of the shift lever in start-
ing.
The shift lever can be shifted from P only wh en the power switch is in ON mode and the
brake pedal is being depressed.

279
4
Driving
RX450h_RX450hL_U4-5. Using the driving support systems
◆PCS (Pre-Collision System)

P. 286
◆LKA (Lane-Keeping Assist)
P. 297
◆Automatic High Beam
P. 262
◆Dynamic radar cruise contro l with full-speed range
 P. 306
Lexus Safety System+
The Lexus Safety System+ consists of the following drive assist systems and
contributes to a safe and comfo rtable driving experience:
WARNING
■Lexus Safety System+
The Lexus Safety System+ is designed to operate under the assumption that the driver
will drive safely, and is designed to help reduce the impact to the occupants and the
vehicle in the case of a collision or assist the driver in normal driving conditions.
As there is a limit to the degree of reco gnition accuracy and control performance that
this system can provide, do not overly rely on this system. The driver is always responsi-
ble for paying attention to the vehicle's surroundings and driving safely.

2974-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
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 assis-
tance 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 operat ing to keep the vehicle in its lane.
The LKA system recognizes visible
white or yellow lines with the camera
sensor on the upper portion of the
windshield.
LKA (Lane-Keeping Assist)
Summary of functions

2994-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
◆Vehicle sway warning
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 dis-
played on the multi-information dis-
play 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 control is not
operating, the lane centering func-
tion does not operate.
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-
information display and the warning
buzzer sounds.

3034-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
■Operation conditions of each function
●Lane departure alert function
This function operates when all of the following conditions are met.
• LKA is turned on.
• Vehicle speed is approximatel y 32 mph (50 km/h) or more.
• System recognizes white (yellow) lines.
• Width of traffic lane is approx imately 9.8 ft. (3 m) or more.
• Turn signal lever is not operated.
• Vehicle is driven on a straight road or around a gentle curve with a radius of more
than approximately 492 ft. (150 m).
• No system malfunctions are detected. ( P. 660)
●Steering assist function
This function operates when all of the follo wing conditions are met in addition to the
operation conditions for the lane departure alert function.
• Setting for “Steering Assist” in of the multi-information display is set to “On”.
(  P. 108)
• Vehicle is not accelerated or dece lerated by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for changing
lanes.
• ABS, VSC, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
●Vehicle sway warning
This function operates when all of the following conditions are met.
• Setting for “Sway Warning” in of the multi-information display is set to “On”.
(  P. 108)
• Vehicle speed is approximatel y 32 mph (50 km/h) or more.
• Width of traffic lane is approx imately 9.8 ft. (3 m) or more.
• No system malfunctions are detected. ( P. 660)
●Lane centering function
This function operates when all of the following conditions are met.
• LKA is turned on.
• Setting for “Lane Center” in of the mu lti-information display are set to “On”.
(  P. 108)
• System recognizes white (yellow) lines.
• Dynamic radar cruise control with full-speed range is operating.
• Width of traffic lane is approximately 8.2 to 13.5 ft. (2.5 to 4.1 m).
• Turn signal lever is not operated.
• Vehicle is driven on a straight road or around a gentle curve with a radius of more
than approximately 656 ft. (200 m).
• No system malfunctions are detected. ( P. 660)
• Vehicle does not accele rate or decelerate by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for changing lanes.
• ABS, VSC, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
• Steering assist function is not operating.

3064-5. Using the driving support systems
RX450h_RX450hL_U
In vehicle-to-vehicle distance control mode, the vehicle automatically a\
cceler-
ates, decelerates and stops to match the speed changes of the preceding vehicle
even if the accelerator pedal is not depr essed. In constant speed control mode,
the vehicle runs at a fixed speed.
Use the dynamic radar cruise control with full-speed range on freeways and
highways.
●Vehicle-to-vehicle distance control mode ( P. 309)
●Constant speed control mode ( P. 315)
Vehicle-to-vehicle distance switch
Display
Set speed
Indicators
Cruise control switch
Dynamic radar cruise control with full-speed range
Summary of functions
1
2
3
4
5

3074-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
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 paying ca reful attention to your surroundings.
●The dynamic radar cruise control with full- speed range provides driving assistance to
reduce the driver's burden. However, there are limitations to the assistance provided.
Read the following conditions carefully. Do not overly rely on this system and always
drive carefully.
• When the sensor may not be correctly detecting the vehicle ahead: P. 317
• Conditions under which the vehicle-to-vehicle distance control mode may not function correctly: P. 318
●Set the speed appropriately depending on the speed limit, traffic flow, road condi-
tions, weather conditions, etc. The driver is responsible for checking the set speed.
●Even when the system is functioning norma lly, the condition of the preceding 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 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 control with full-speed range off using the “ON/
OFF” button 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 following distance
The dynamic radar cruise control with full-speed range is only intended to help the
driver in determining the following distan ce between the driver’s own vehicle and a
designated vehicle traveling ahead. It is no t a mechanism that allows careless or inat-
tentive driving, and it is not a system that can assist the driver in low-visibility condi-
tions. It is still necessary for driver to pa y 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 fol-
lowing distance between 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 vigilant 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 pre-
vent or avoid a collision with a vehicle trave ling ahead. Therefore, if there is ever any
danger, the driver must take immediate and direct control of the vehicle and act
appropriately in order to ensure the safety of all involved.

3084-5. Using the driving support systems
RX450h_RX450hL_U
WARNING
■Situations unsuitable for dynamic rada r cruise control with full-speed range
Do not use dynamic radar cruise control with full-speed range in any of the following
situations.
Doing so may result in inappropriate speed control and could cause an accident result-
ing in death or serious injury.
●Roads where there are pedestrians, cyclers, etc.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered 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 sensors from
detecting correctly (fog, snow, sandstorm, heavy rain, etc.)
●When there is rain, snow, etc. on the fron t surface of the radar sensor or camera sen-
sor
●In traffic conditions that require frequent repeated a cceleration and deceleration
●When your vehicle is towing a trailer or during emergency towing
●When an approach warning buzzer is heard often