trailer LEXUS RX450h 2018 Owner's Manual

294 4-5. Using the driving support systems
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Situations in which the system may not operate properly ●
In some situations such as the following, a vehicle may not be detected by the radar
sensor and camera sensor, preventing the system from operating properly:
• If an oncoming vehicle is approaching your vehicle
• If a vehicle ahead is a motorcycle or bicycle
• When approaching the side or front of a vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shap ed, such as a tractor or side car
• If the sun or other light is shin ing directly on a vehicle ahead
• If a vehicle cuts in front of your ve hicle or emerges from beside a vehicle
• If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, accelera-
tion or deceleration)
• When suddenly cutting behind a preceding vehicle
• When driving in inclement we ather such as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, sn ow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the surrounding brightness changes suddenly, such
as at the entrance or exit of a tunnel
• When a very bright light, such as the sun or the headlights of on coming traffic, shines
directly into the camera sensor
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a
tunnel• If a preceding vehicle has a low rear end,
such as a low bed trailer
• If a vehicle ahead has extremely high
ground clearance
• When a vehicle ahead is not directly in front
of your vehicle

300 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85UWARNING ■
Before using LKA system
Do not rely solely upon the LKA system. LKA is not a system which automatically
drives the vehicle or reduces the amount of attention that must be paid to the area in
front of the vehicle. The driver must always assume full responsibility for driving safely
by always paying careful attention to the surrounding conditions and operate the steer-
ing wheel to correct the path of the vehicle. Also, make sure to take adequate breaks
when fatigued, such as from driv ing for a long period of time.
Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury. ■
To avoid operating LKA by mistake
When not using the LKA system, use the LKA switch to turn the system off. ■
Situations unsuitable for LKA
Do not use the LKA system in the following situations.
The system may not operate properly and lead to an accident, resulting in death or
serious injury. ●
A spare tire, tire chains, etc., are equipped. ●
When the tires have been excessively worn, or when the tire inflation pressure is low. ●
Tires which differ by structure, manufacturer, brand or tread pattern are used. ●
Objects or patterns that could be mistaken for white (yellow) lines are present on the
side of the road (guardrails, cu rbs, reflective poles, etc.).●
Vehicle is driven on a snow-covered road. ●
White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.●
Asphalt repair marks, white (y ellow) line marks, etc., are present due to road repair.●
Vehicle is driven in a temporary lane or restricted lane due to construction work.●
Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow,
freezing, etc. ●
Vehicle is driven in traffic lanes ot her than on highways and freeways.●
Vehicle is driven in a construction zone. ●
When your vehicle is towing a trailer or during emergency towing ■
Preventing LKA system malfunctions and operations perf ormed by mistake●
Do not modify the headlights or place stickers, etc., on the surface of the lights.●
Do not modify the suspension etc. If the suspension etc. needs to be replaced, con-
tact your Lexus dealer. ●
Do not install or place anything on the hood or grille. Also, do not install a grille guard
(bull bars, kangaroo bar, etc.). ●
If your windshield needs repair s, contact your Lexus dealer.

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

326 4-5. Using the driving support systems
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Conditions under which the BSM function may not function correctly ●
The BSM function may not detect vehicles correctly in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When mud, snow, ice, a sticke r, etc. is covering the sensor or surrounding area on
the rear bumper
• When driving on a road surf ace that is wet with standi ng water during bad weather,
such as heavy rain, snow, or fog
• When multiple vehicles are approaching wi th only a small gap between each vehicle
• When the distance between your vehicle and a following vehicle is short
• When there is a significant difference in speed between your vehicle and the vehicle
that enters the detection area
• When the difference in speed between your vehicle and another vehicle is changing
• When a vehicle enters a detection area traveling at about the same speed as your
vehicle
• As your vehicle starts from a stop, a vehicle remains in the detection area
• When driving up and down cons ecutive steep inclines, such as hills, dips on the road,
etc.
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When vehicle lanes are wide, or when driving on the edge of a lane, and the vehicle
in an adjacent lane is far away from your vehicle
• When towing a trailer (vehicles with towing package)
• When items such as a bicycle carrier are installed on the rear of the vehicle
• When there is a significant difference in height between your vehicle and the vehicle
that enters the detection area
• Immediately after the BSM function is turned on ●
Instances of the BSM function unnecessarily detecting a vehicle and/or object may
increase in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When the distance between your vehicle and a guardrail, wall, etc. that enters the
detection area is short
• When driving up and down cons ecutive steep inclines, such as hills, dips on the road,
etc.
• When vehicle lanes are narrow, or when driv ing on the edge of a lane, and a vehicle
traveling in a lane other than the ad jacent lanes enters the detection area
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When the tires are slipping or spinning
• When the distance between your vehicle and a following vehicle is short
• When a bicycle carrier or other accessory is installed to the rear of the vehicle
• When towing a trailer (vehicles with towing package)

330 4-5. Using the driving support systems
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Conditions under which the RCTA fu nction will not detect a vehicle
The RCTA function is not designed to detect the following types of vehicles and/or
objects: ●
Vehicles approaching from directly behind ●
Vehicles backing up in a parkin g space next to your vehicle
●
Guardrails, walls, signs, parked vehi cles and similar stationary objects
*●
Small motorcycles, bicycles, pedestrians, etc.
*●
Vehicles moving away from your vehicle ●
Vehicles approaching from the parking spaces next to your vehicle
*
* : Depending on the conditions, detection of a vehicle and/or object may occur.■
Conditions under which the RCTA function may not function correctly ●
The RCTA function may not detect vehicles correctly in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When mud, snow, ice, a sticke r, etc. is covering the sensor or surrounding area on
the rear bumper
• When driving on a road surf ace that is wet with standi ng water during bad weather,
such as heavy rain, snow, or fog
• When multiple vehicles are approaching wi th only a small gap between each vehicle
• When a vehicle is approaching at high speed
• When towing a trailer (vehicles with towing package) ●
Vehicles that the sensors cannot detect due to
obstructions
• When backing up on a slope with a sharp
change in grade

382 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85U◆ ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corresponding
to the brake operation
◆ ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the br akes are applied suddenly, or if the
brakes are applied while drivin g on a slippery road surface
◆ Brake assist
Generates an increased level of br aking force after the brake pedal is
depressed when the system detects a panic stop situation
◆ VSC (Vehicle Stability Control)
Helps the driver to contro l skidding when swerving suddenly or turning on
slippery road surfaces.
◆ Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆ Trailer Sway Control (if equipped)
Helps the driver to control trailer sway by selectively applying brake pressure
for individual wheels and reducing dr iving torque when trailer sway is
detected.
◆ TRAC (Traction Control)
Helps to maintain drive power and pr event the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆ Hill-start assist control
Helps to reduce the backward movement of the vehicle when starting on an
uphillDriving assist systems To keep driving safety and performance, the following systems operate auto-
matically in response to various drivin g situations. Be aware, however, that
these systems are supplementary and shou ld not be relied upon too heavily
when operating the vehicle.

384 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85UThe slip indicator light will flash while
the TRAC/VSC/ABS/Trailer Sway
Control systems are operating.
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may reduce
power from the hybrid system to the wheels. Pressing to turn the system
off may make it easier for you to ro ck the vehicle in order to free it.
To turn the TRAC system off, quickly
press and release . The “Traction Control Turned Off”
will be shown on the multi-informa-
tion display. Press again to
turn the system back on.When the TRAC/VSC/ABS/ Trailer Sway Control systems are operat-
ing
Disabling the TRAC system

3854-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85U■
Turning off both TRAC VSC and Trailer Sway Control systems
To turn the TRAC VSC and Trailer Sway Co ntrol systems off, press and hold for
more than 3 seconds whil e the vehicle is stopped.
The VSC OFF indicator light will come on an d the “Traction Control Turned Off” will be
shown on the multi-information display.
*Press again to turn the systems back on.
* : On vehicles with PCS (Pre-Collision Sy stem), pre-collision brake assist and pre-
collision braking will also be disabled. The PCS warning light will come on and a
message will be displa yed on the multi-info rmation display. ( → P. 296) ■
When the message is displayed on the mu lti-information displa y showing that TRAC
has been disabled even if has not been pressed
TRAC cannot be operated. Contact your Lexus dealer.■
Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:●
The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline). ●
The vehicle is stopped ●
The accelerator pedal is not depressed ●
The parking brake is not engaged ■
Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations: ●
The shift lever is shifted to P or N ●
The accelerator pedal is depressed ●
The parking brake is engaged ●
2 seconds at maximum elapsed after the brake pedal is released ■
Sounds and vibrations caused by the ABS, brake assist, VSC, Trailer Sway Control,
TRAC and hill-start assist control systems ●
A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the hybrid system is started or just after the vehicle begins
to move. This sound does not indicate that a malfunction has occurred in any of these
systems. ●
Any of the following conditions may occur when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a stop.

386 4-5. Using the driving support systems
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ECB operating sound
ECB operating sound may be heard in the followi ng cases, but it does not indicate that a
malfunction has occurred. ●
Operating sound heard from the engine compartment when the brake pedal is oper-
ated. ●
Motor sound of the brake system heard from the front part of the vehicle when the
driver’s door is opened. ●
Operating sound heard from the engine compartment when one or two minutes
passed after the stop of the hybrid system. ■
EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction. ■
Automatic reactivation of TRAC, Tr ailer Sway Control and VSC systems
After turning the TRAC, Trailer Sway Contro l and VSC systems off, the systems will be
automatically re-enabled in the following situations: ●
When the power switch is turned off ●
If only the TRAC system is turned off, the TRAC will turn on when vehicle speed
increases
If both the TRAC and VSC systems are turned off, au tomatic re-enabling will not
occur when vehicle speed increases. ■
Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result . Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor-
mal within 10 minutes.
WARNING ■
The ABS does not operate effectively when ●
The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road). ●
The vehicle hydroplanes while driving at high speed on wet or slick roads.■
Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehi cle’s stopping distance . Always maintain a
safe distance from the vehicle in front of you, especially in the following situations: ●
When driving on dirt, grav el or snow-covered roads●
When driving with tire chains ●
When driving over bumps on the road ●
When driving over roads with potholes or uneven surfaces■
TRAC/VSC may not operate effectively when
Directional control an d power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC/VSC system is op erating. Drive the vehi cle carefully in con-
ditions where stability and power may be lost.

3874-5. Using the driving support systems
4
Driving
RX450h_RX450hL _U_OM48F85UWARNING ■
Hill-start assist control does not operate effectively when ●
Do not overly rely on hill-start assist control. Hill-start assist control may not operate
effectively on steep inclines and roads covered with ice. ●
Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle
stationary for an exte nded period of time. Do not atte mpt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident. ■
When the TRAC/VSC/Trailer Sw ay Control is activated
The slip indicator light flashes. Always drive carefully. Reckle ss driving may cause an
accident. Exercise particular care when the indicator light flashes.■
When the TRAC/VSC/Trailer Sway Control systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As these
are the systems to help ensure vehicle stab ility and driving force, do not turn the
TRAC/VSC/Trailer Sway Contro l systems off unless necessary.
Trailer Sway Control is part of the VSC syst em and will not operate if VSC is turned off
or experiences a malfunction. ■
Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tire s are inflated to the recommended tire infla-
tion pressure level.
The ABS, TRAC, Trailer Sway Control and VS C systems will not function correctly if
different tires are installed on the vehicle.
Contact your Lexus dealer for further in formation when replacing tires or wheels.■
Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension w ill affect the driving
assist systems, and may cause a system to malfunction. ■
Trailer Sway Control precaution
The Trailer Sway Control system is not able to reduce trailer sway in all situations.
Depending on many factors such as the condit ions of the vehicle, trailer, road surface,
and driving environment, the Trailer Sway Control system may not be effective. Refer to
your trailer owner’s manual for information on how to tow your trailer properly. ■
If trailer sway occurs
Observe the following precautions.
Failing to do so may cause death or serious injury. ●
Firmly grip the steering wh eel. Steer straight ahead.
Do not try to control trailer sway by turning the steering wheel.●
Begin releasing the accelerator pedal immediately but very gradually to reduce
speed.
Do not increase speed. Do not apply vehicle brakes.
If you make no extreme correction with the steering or brakes, your vehicle and trailer
should stabilize. ( → P. 234)