wheel LEXUS RC300 2017 Service Manual

2924-5. Using the driving support systems
WARNING
■When using the Lexus parking assist monitor system
The parking assist monitor is a supplemental device intended to assist the driver when
backing up. When backing up, be sure to check visually behind and all around the vehi-
cle before proceeding.
Observe the following precautions to avoid an accident that could result in death or
serious injuries.
●Never depend on the parking assist monitor entirely when backing up. The image
and the position of the guide lines displaye d on the screen may differ from the actual
state.
Use caution, just as you woul d when backing up any vehicle.
●Be sure to back up slowly, depressing the brake pedal to control vehicle speed.
●If you seem likely to hit nearby vehicles, obstacles, people or mount the shoulder,
depress the brake pedal to stop the vehicle.
●The instructions given are only guidelines.
When and how much to turn the steering wh eel will vary according to traffic condi-
tions, road surface conditions , vehicle condition, etc. when parking. It is necessary to
be fully aware of this before using the parking assist system.
●When parking, be sure to check that the parking space will accommodate your vehi-
cle before maneuvering into it.
●Do not use the parking assist monitor in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or emergency tires
• When the trunk is not closed completely
• On roads that are not flat or stra ight, such as curves or slopes.
●In low temperatures, the screen may darken or the image may become faint. The
image could distort when the vehicle is movi ng, or you may become unable to see the
image on the screen. Be sure to check dire ct visually and with the mirrors all around
the vehicle before proceeding.
●If the tire sizes are changed, the position of the guide lines displayed on the screen
may change.
●The camera uses a special lens. The distances between objects and pedestrians that
appear in the image displayed on the screen will differ from the actual distances.
( → P. 287)
●Estimated course line display mode: If the st eering wheel is straight and the vehicle
width guide lines and the estimated course lines are not in alignment, have the vehicle
inspected by your Lexus dealer.

2984-5. Using the driving support systems
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes 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.
◆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 prevent the vehicle from rolling backward when starting on an incline
or slippery slope
◆VGRS (Variable Gear Ratio Steering) (if equipped)
Adjusts the front wheel turning angle in accordance with the vehicle speed
and steering wheel movement
◆DRS (Dynamic Rear Steering) (if equipped)
Contributes to the turning characteristi cs and responsiveness of the vehicle
by slightly adjusting the rear wheel angle of the vehicle in accordance with
steering wheel movement.
Driving assist systems
To help enhance driving safety and perf ormance, the following systems oper-
ate automatically in response to variou s driving situations. Be aware, however,
that these systems are supplementary and should not be relied upon too heav-
ily when operating the vehicle.

2994-5. Using the driving support systems
4
Driving
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel
◆Adaptive Variable Suspen sion System (if equipped)
By independently controlling the dampin g force of the shock absorbers for
each of the 4 wheels according to the ro ad and driving conditions, this system
combines riding comfort with superior steering stability, and helps good vehi-
cle posture. (→ P. 295)
◆LDH (Lexus Dynamic Hand ling system) (if equipped)
Provides integrated control of the VGRS, DRS and EPS. Contributes to turn-
ing characteristics at low speeds, responsiveness at medium speeds and
safety at high speeds by controlling th e steering angle of the front and rear
wheels in accordance with the steering wheel operation and vehicle speed.
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, EPS, VGRS (if equipped) and DRS (if equipped) systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes, engine output, steering assist, and if equipped with
VGRS, steering ratio
◆PCS (Pre-Collision Sy stem) (if equipped)
→ P. 306
◆BSM (Blind Spot Monitor) (if equipped)
→P. 313
◆TVD (Torque Vectoring Di fferential) (if equipped)
→ P. 329

3004-5. Using the driving support systems
The slip indicator light will flash while
the TRAC/VSC systems are operating.
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may reduce
power from the engine 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.
RC350/RC300/RC200t
To turn the TRAC system off, quickly
press and release .
The “TRAC OFF” will be shown on the
multi-information display.
Press again to turn the system
back on.
When the TRAC/VSC systems are operating
Disabling the TRAC system

3024-5. Using the driving support systems
■Expert mode (RC F)
When expert mode is selected, it is possible to drive in a more sp orty manner than other
drive modes. Expert mode disables the TRAC and VSC systems but the engine and
brakes may be controlled depending on the vehicle behavior.
■When the message is displayed on the mu lti-information display showing that TRAC
has been disabled even if has not been pressed (RC350/RC300/RC200t)
TRAC and hill-start assist control cannot be operated. Contact your Lexus dealer.
■When the “TRAC OFF” indicator light comes on even if ( ) has not been
pressed (RC F)
TRAC and hill-start assist control cannot be operated. Contact your Lexus dealer.
■VGRS is disabled when
VGRS may stop operating in the following situations.
In this event, the steering wheel may move from its straight forward position, but it will
return when the system restarts.
●When the steering wheel is operated for an extended period of time while the vehicle is
stopped or is moving very slowly
(on vehicles with LDH, DRS is disabled together with VGRS)
●When the steering wheel has been held fully to the left or right
The center position of the steering wheel may change when VGRS is disabled. However,
the position will return to normal after VGRS is reactivated.
■When the battery is disconnected (vehicles with VGRS)
The steering wheel may move from its straight forward position, but this will be corrected
automatically when driving. To select expert mode, press
()
when in SPORT S+ mode.
The “EXPERT” indicator will come on together
with the TRAC OFF and VSC OFF indicators.
To cancel expert mode, press
() or
use the driving mode sele ct switch to select a
driving mode other than SPORT S+ mode.

3034-5. Using the driving support systems
4
Driving
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC, hill-start assist
control and VGRS systems
●A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the engine is started or just after the vehicle begins to
move. This sound does not indicate that a malfunction has occurred in any of these sys-
tems.
●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 afte r the vehicle comes to a stop.
• The brake pedal may pulsate slig htly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound may be heard. This does not indi-
cate a malfunction.
■Reactivation of the TRAC/VSC systems
Even after the TRAC/VSC systems have been turned off, turning the engine off and then
on again will automatically reactivate the TRAC/VSC systems.
■Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases. However, wh en both TRAC/VSC systems are turned off, the systems
will not turn on even 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 engine off. The EPS system should return to normal
within 10 minutes.
■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 moved to P or N.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse af ter the brake pedal is released.

3054-5. Using the driving support systems
4
Driving
WARNING
■When the TRAC/VSC 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 stability and driving force, do not turn the
TRAC/VSC systems off unless necessary.
■Expert mode precautions
●Do not use on public roads.
●Use only when the road co nditions and safety of the surrounding area can be
ensured.
●Proper use of expert mode requires a professional level of driving skill. When using
expert mode, always check the road condit ions and surrounding area and drive more
carefully than usual.
■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 and VSC 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 will affect the driving
assist systems, and may cause a system to malfunction.

3074-5. Using the driving support systems
4
Driving
◆Steering control (if equipped)
When the system determines that there is a high possibility of a frontal colli-
sion while the steering wheel is being operated, the LDH (Lexus Dynamic
Handling) system controls the steering angle of the front and rear wheels and
torque applied to the steering wheel to enhance the steering wheel operation
response.
Enabled
Disabled
The pre-collision system warning light
comes on when pre-collision system is
disabled.
The radar sensor detects vehicles or
other obstacles on or near the road
ahead and determines whether a colli-
sion is imminent based on the position,
speed, and heading of the obstacles.
Disabling pre-collision system
1
2
Radar sensor

3094-5. Using the driving support systems
4
Driving
■Conditions that may trigger the system even if there is no danger of a collision
In any of the following situations where the frontal area of the radar sensor is inter-
rupted, the radar sensor may detect possibility of a frontal collision and the system
may be activated.
●When passing by an oncoming vehicle in a curve or a turn to the right or the left
●When rapidly approaching an obstacle ahead (e.g. preceding vehicle, toll gate barrier,
etc.)
●When there is a structural object (billboar d, low ceiling, fluorescent light, etc.) above
the uphill road ahead
●When driving on a narrow road or throug h under a low overhead structure (bridge,
tunnel, fly-under, etc.)
●When driving on an uneven road surface
●When there is a metal object, bump, or protrusion on the road surface
●When vehicle’s front part is raised or lowered depending on loading conditions
●When the direction of radar sensor is misa ligned by strong impact applied on an area
around the radar sensor, etc.
●When there is an obstacle (guard rail, etc.) by the roadside at the entrance to a curve
●When the front of your vehicle is pointing upwards (caused by putting a heavy load in
the trunk etc.)
When the system is activated in the situations described above, there is also a possibility
that the brakes may be applied wi th a force greater than normal.
■Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may also be occa-
sions when the sensor cannot de tect pedestrians, animals, bicycles, motorcycles, trees,
or snowdrifts.
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp bends or uneven surfaces
●If a vehicle suddenly moves in front of yo ur vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heavy rain, fog, snow or sand storms
●If the vehicle is skidding when VSC is not operating
●When your vehicle is steeply inclined
●When only part of your vehicle’s front end collides with, or contacts, a vehicle or object
in a frontal collision
●When the radar sensor moves off position du e to its surrounding area being subjected
to a strong impact
●When an obstacle suddenly appears in front of the vehicle due to the steering wheel
being turned sharply or another cause
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor cont amination, etc. that results in the sensors
being unable to detect obstac les, the pre-collision system will be automatically disabled.
In this case, the system will not activate even if there is a collision possibility.

3114-5. Using the driving support systems
4
Driving
WARNING
■Limitations of the pre-collision system
●The driver is solely responsible for safe driving. Always drive safely, taking care to
observe your surroundings.
Do not use the pre-collision system instea d of normal braking operations under any
circumstances. This system will not prevent collisions or lessen damage or injuries in
all cases. Do not overly rely on this syst em. Failure to do so may cause an accident,
resulting in death or serious injury.
●This system has been designed to help av oid and reduce the impact of collisions.
However, the system operates differently depending on the situation ( →P. 308,
309). As a result, the same level of performance may not be expected in all cases.
Also, the pre-collision brakes may not operate if the driver is depressing the brake
pedal or turning the steering wheel, as the system will determine such conditions as
collision avoidance operations.
●As the pre-collision system is designed to assist the driver in safe driving, it may oper-
ate under sporty driving conditions, whic h may cause an accident. For this reason
under sporty driving conditions, it is reco mmended that this system be disabled by
using the PCS OFF switch.
■Handling the radar sensor
Observe the following to ensure the pre-co llision system can function effectively.
Otherwise, the system may not function correctly and could result in an accident.
●Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or damage
them.
●Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even s lightly off position, the system may become inaccurate or
malfunction. If the sensor or surrounding area is subject to a strong impact, always
have the area inspected and adjusted by your Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding area.
●Do not modify or paint the sensor and grille cover.
●If the radar sensor needs to be replaced, contact your Lexus dealer.