LEXUS RX450h 2018 Owners Manual

3014-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85UPress the LKA switch to turn the LKA
system on. The LKA indicator illuminates and a
message is displayed on the multi-infor-
mation display.
Press the LKA switch again to turn the
LKA system off.
When the LKA system is turned on or
off, operation of the LKA system contin-
ues in the same cond ition the next time
the hybrid system is started.Turning LKA system on

302 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85ULKA indicator
The illumination condition of the
indicator informs the driver of the
system operation status. Illuminated in white:
LKA system is operating.
Illuminated in green:
Steering wheel assistance of the steer-
ing assist function or lane centering
function is operating.
Flashing in amber:
Lane departure alert function is operat-
ing.
Operation display of steering wheel
operation support
Indicates that steering wheel assistance of the steering assist function or lane
centering function is operating.
Lane departure alert function display
Displayed when the multi-information disp lay is switched to the driving assist
system information screen.Indications on the multi-information display 1
2
3
Inside of displayed white lines is
white 
Inside of displayed white lines is
black
Indicates that the system is recognizing
white (yellow) lines. When the vehicle
departs from its lane, the white line dis-
played on the side the vehicle departs
from flashes amber. Indicates that the system is not able to
recognize white (ye llow) lines or is
temporarily canceled.

3034-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85U■
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 stra ight 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 stra ight 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.

304 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85U■
Temporary cancellation of functions
When operation conditions are no longer met, a function may be temporarily canceled.
However, when the operation co nditions are met again, operat ion of the function is auto-
matically restored. ( → P. 303)■
Steering assist function/lane centering function
Depending on the vehicle speed, lane depart ure situation, road conditions, etc., the
operation of the functions may not be reco gnized or the functions may not operate.■
Lane departure alert function
The warning buzzer may be difficult to hear due to external noise, audio playback, etc.
Also, it may be difficult to f eel steering wheel vibrations due to the road conditions, etc.■
Hands off steering wheel alert
When the system determines that the driver has removed their hands from the steering
wheel while the steering assist function or lane centering function is operating, a warning
message is displayed on the multi-info rmation display and the buzzer sounds.■
White (yellow) lines are only on one side of road
The LKA system will not operate for the side on which white (yellow) lines could not be
recognized.

3054-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85U■
Conditions in which functions may not operate properly
In the following situations, the camera sensor may not detect white (yellow) lines and var-
ious functions may not operate normally. ●
There are shadows on the road that run parallel with, or cover, the white (yellow) lines. ●
The vehicle is driven in an ar ea without white (yellow) lines, such as in front of a tollgate
or checkpoint, or at an intersection, etc.●
The white (yellow) lines are cracked, “Botts ’ dots”, “Raised pavement marker” or stones
are present. ●
The white (yellow) lines cannot be seen or are difficult to see due to sand, etc. ●
The vehicle is driven on a road surface that is wet due to rain, puddles, etc. ●
The traffic lines are yellow (which may be more difficult to recognize than lines that are
white). ●
The white (yellow) lines cross over a curb, etc. ●
The vehicle is driven on a bright surface, such as concrete. ●
The vehicle is driven on a surface that is bright due to reflected light, etc. ●
The vehicle is driven in an area where the brightness changes suddenly, such as at the
entrances and exits of tunnels, etc.●
Light from the headlights of an oncoming vehicle, the sun, etc., enters the camera.●
The vehicle is driven where the road diverges, merges, etc. ●
The vehicle is driven on a slope. ●
The vehicle is driven on a road which t ilts left or right, or a winding road.●
The vehicle is driven on an unpaved or rough road. ●
The vehicle is driven around a sharp curve. ●
The traffic lane is excessively narrow or wide. ●
The vehicle is extremely tilted due to carry ing heavy luggage or having improper tire
pressure. ●
The distance to the preceding vehicle is extremely short. ●
The vehicle is moving up and down a large am ount due to road conditions during driv-
ing (poor roads or road seams). ●
The headlight lenses are dirty and emit a faint amount of light at night, or the beam axis
has deviated. ●
The vehicle is struck by a crosswind. ●
The vehicle has just changed lane s or crossed an intersection.●
Snow tires, etc., are equipped. ■
If the LKA indicator is illuminated in ambe r and a warning message is displayed on the
multi-information display
→ P. 660 ■
Customization
Some functions can be customized. ( → P. 108)

306 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85UIn vehicle-to-vehicle distance control mode, the vehicle automatically acceler-
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 switchDynamic radar cruise control with full-speed rangeSummary of functions 1
2
3
4
5

3074-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85UWARNING ■
Before using dynamic radar cruise control with full-speed range
Driving safely is the sole responsibility of th e driver. Do not rely solely on the system,
and drive safely by always paying careful attention to your surroundings.
The dynamic radar cruise cont rol with full-speed range prov ides driving assistance to
reduce the driver's burden. However, there are limitations to the assistance provided.
Set the speed appropriately depending on the speed limit, traffic flow, road conditions,
weather conditions, etc. The driver is responsible for chec king 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. There-
fore, 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, resultin g in death or serious injury.■
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 cont rol 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 judg e 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.■
To avoid inadvertent dynamic radar cruise control with full-speed range activation
Switch the dynamic radar cruise control wi th full-speed range off using the “ON/OFF”
button when not in use.

308 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85UWARNING ■
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

3094-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85UThis mode employs a radar sensor to detect the presence of vehicles up to
approximately 328 ft. (100 m) ahead, de termines the current vehicle-to-vehicle
following distance, and operates to main tain a suitable following distance from
the vehicle ahead. Note that vehicle-to-vehicle distance will cl ose 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 dis-
tance 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 sl ower than the set speed appearsWhen a vehicle is detected running ahead of you, the system automatically deceler-
ates 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). Th e 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 the system cannot
decelerate sufficie ntly to prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehicle will also stop (vehicle is stopped by
system 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 reached. The system then returns to con-
stant speed cruising.Driving in vehicle-to-vehicle distance control mode
1
2
3

310 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85UPress the “ON/OFF” button to acti-
vate the cruise control. 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. 315)
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 vehicl e speed is below appr oximately 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).Setting the vehicle speed (vehicle-to-vehicle distance control mode) 1
2