2020 LEXUS RX450H cruise control

2384-2. Driving procedures
RX350/RX350L_U
■S mode
●When the shift range is 6 or lower, holding th e shift lever toward “+” sets the shift range
to 8.
●To prevent the engine from over-revving, upshifting may automatically occur.
●To protect the automatic transmission, a functi on is adopted that automatically selects a
higher shift range when the fluid temperature is high.
■To protect the automatic transmission
If the automatic transmission fluid temperature is high, “Transmission Fluid Temp High
See Owner’s Manual” will be displayed on the multi-information display and the vehicle
will go into transmission protection mode automatically. Have the vehicle inspected by
your Lexus dealer.
■Downshifting restrictions 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 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.
●While driving in D or S mode, downshifting to 7, 6, 5 or 4. ( P. 300)
●When switching the driving mode to spor t mode while driving in the D position
(  P. 373)
■Restraining sudden start (Drive-Start Control)
When the following unusual operation is performed, the engine 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 when the engine switch is in IGNITION ON
mode and the brake pedal is being depressed.

2434-2. Driving procedures
4
Driving
RX350/RX350L_U
■Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
●The “+” paddle shift switch is held down for a period of time
●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
■To protect the automatic transmission
If the automatic transmission fluid temperature is high, “Transmission Fluid Temp High
See Owner’s Manual” will be displayed on the multi-information display and the vehicle
will go into transmission protection mode automatically. Have the vehicle inspected by
your Lexus dealer.
■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 shif t switch 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.
●While driving in D position, downshifting to 7, 6, 5 or 4. ( P. 300)
●When switching the driving mode to spor t mode while driving in the D position
(  P. 373)
■Restraining sudden start (Drive-Start Control)
When the following unusual operation is performed, the engine 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
M) with the accelerator pedal depressed, a warning message appears on the multi-
information display. If a wa rning 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 when the engine switch is in IGNITION ON
mode and the brake pedal is being depressed.

274
RX350/RX350L_U4-5. Using the driving support systems
◆PCS (Pre-Collision System)

P. 281
◆LKA (Lane-Keeping Assist)
P. 291
◆Automatic High Beam
P. 256
◆Dynamic radar cruise contro l with full-speed range
 P. 300
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.

2914-5. Using the driving support systems
4
Driving
RX350/RX350L_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

2934-5. Using the driving support systems
4
Driving
RX350/RX350L_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.

2974-5. Using the driving support systems
4
Driving
RX350/RX350L_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. 654)
●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. 97)
• 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. 97)
• 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. 654)
●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. 97)
• 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. 654)
• 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.

3004-5. Using the driving support systems
RX350/RX350L_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. 303)
●Constant speed control mode ( P. 309)
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

3014-5. Using the driving support systems
4
Driving
RX350/RX350L_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. 311
• Conditions under which the vehicle-to-vehicle distance control mode may not function correctly: P. 312
●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.