brake LEXUS RCF 2019 Service Manual

2794-5. Using the driving support systems
4
Driving
RC F_U ■
Conditions under which the ve hicle-to-vehicle distance co ntrol mode may not function
correctly
In the case of the following conditions, o perate the brake pedal (or accelerator pedal,
depending on the situ ation) as necessary.
As the sensor may not be able to correctly detect vehicles ahead, the system may not
operate properly.
●
When the vehicle ahead of you decelerates suddenly ●
When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.) ●
Preceding vehicle has an extremely high
ground clearance
●
When the road curves or when the lanes are
narrow
●
When steering wheel operation or your posi-
tion in the lane is unstable

288 4-5. Using the driving support systems
RC F_U WARNING ■
When using the intuitive parking assist
Observe the following precautions.
Failing to do so may result in the vehicle be ing unable to be driv en safely and possibly
cause an accident. ●
Do not use the sensor at speeds in excess of 6 mph (10 km/h). ●
The sensors’ detection areas and reaction ti mes are limited. When moving forward or
reversing, check the areas surrounding the vehicle (especially th e sides of the vehi-
cle) for safety, and drive slowly, using the brake to control the vehicle’s speed. ●
Do not install accessories within the sensors’ detection areas.■
Limitations of the sensors ●
RC350/RC300: The detection areas of the sensors are limited to the areas around
the vehicle’s front and rear bumpers. ●
RC F: The detection areas of the sensors are limited to the areas around the vehicle’s
front corners and the rear bumpers. ●
Certain vehicle conditions and surrounding environments, such as the following, may
affect the ability of th e sensors to correctly detect obje cts. Pay particul ar attention in
the following situations. Failure to do so may result in the vehicle being driven
unsafely, possibly leading to an accident.
• When there is dirt, snow or ice on a se nsor (Cleaning the sensor will resolve this
problem.)
• When the sensor is frozen (Thawing the area will resolve this problem.)
In especially cold weather, if a sensor is frozen the screen may show an abnormal
display, or objects may not be detected
• When a sensor is covered in any way
• When the vehicle is leaning considerably to one side
• When driving on an extremely bump y road, incline, gravel, or grass
• When the vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines,
air brakes of large vehicles, or other loud noises producing ultrasonic waves
• When there is another vehicle equipped with parking assist sensor in the vicinity
• When the sensor is coated with a sheet of spray or heavy rain
• When the vehicle is equipped with a fender pole or wireless antenna
• When a towing eyelet is installed
• When a bumper or sensor receives a strong impact
• When the vehicle is approaching a tall or curved curb
• When driving in harsh sunlig ht or intense cold weather
• When an object is directly under a bumper
• When objects become too close to the sensors
• When a non-genuine Lexus suspension (lowered suspension, etc.) is installed
In addition to the situations above, there are instances in which, because of their
shape, signs and other objects may be judged by the sensor to be closer than they
are.

312 4-5. Using the driving support systems
RC F_U ◆ 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.
◆ 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 starti ng on an incline
◆ 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 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.

3134-5. Using the driving support systems
4
Driving
RC F_U ◆ 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 wi th superior vehicle stability, and helps good vehi-
cle posture. (  P. 302)
◆ 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 equi pped) 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

3154-5. Using the driving support systems
4
Driving
RC F_U 
RC F
To turn the TRAC system off, quickly
press and release ( ). The “TRAC OFF” indicator light will
come on.
Press ( ) again to turn the
system back on. ■
Turning off both TRAC and VSC systems 
RC350
/RC300To turn the TRAC and VSC systems off, pr ess and hold for more than 3 seconds
while 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.
* 1
Press again to turn the systems back on. 
RC F
To turn the TRAC and VSC systems off, press and hold ( ) for more than
3 seconds.
The “TRAC OFF” indicator li ght and the VSC OFF indica tor light will come on.
* 2
Press ( ) again to turn the systems back on.
* 1
: On vehicles with PCS (Pre-Collision System ), pre-collision brake assist, pre-collision
braking, and steering control (performed through cooperative control of PCS and
LDH) (if equipped) will also be disabled. The pre-collision system warning light will
come on and a message will be displaye d on the multi-information display. (  P. 460)
* 2
: On vehicles with PCS (Pre-Collision Syst em), pre-collision brake assist and pre-
collision braking will also be disabled. The pre-collision system warning light will come
on and a message will be displayed on the multi-information display. (  P. 460)

316 4-5. Using the driving support systems
RC F_U ■
Expert mode (RC F)
When expert mode is se lected, 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 displa y showing that TRAC
has been disabled even if has not been pressed (RC350/RC300)
TRAC cannot be operated. Contact your Lexus dealer.■
When the “TRAC OFF” indicator light comes on even if
( ) has not been
pressed (RC F)
TRAC 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.

3174-5. Using the driving support systems
4
Driving
RC F_U ■
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 s lightly after the ABS is activated.■
EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate 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 sy stem 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.

318 4-5. Using the driving support systems
RC F_U 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 in the road ●
When driving over roads with potholes or uneven surfaces■
TRAC 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 system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.■
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 VSC 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.

3214-6. Driving tips
4
Driving
RC F_U Perform the following according to the driving conditions: ●
Do not try to forcibly open a window or move a wiper that is frozen. Pour
warm water over the frozen area to me lt the ice. Wipe away the water imme-
diately to prevent it from freezing. ●
To ensure proper operation of the c limate control system fan, remove any
snow that has accumulated on the air inlet vents in front of the windshield. ●
Check for and remove any excess ice or snow that may have accumulated on
the exterior lights, vehicle’s roof, chassi s, around the tires or on the brakes.●
Remove any snow or mud from the bottom of your shoes before getting in the
vehicle.
Accelerate the vehicle slowly, keep a sa fe distance between you and the vehicle
ahead, and drive at a reduced spee d suitable to road conditions.●
Park the vehicle and move the shift lever to P without setting the parking
brake. The parking brake may freeze up, preventing it from being released. If
the vehicle is parked without setting the parking brake, make sure to block the
wheels.
Failure to do so may be dangerous because it may cause the vehicle to move
unexpectedly, possibly leading to an accident. ●
If the vehicle is parked without setting the parking brake, confirm that the shift
lever cannot be moved out of P
* .
* : The shift lever will be locked if it is atte mpted to be shifted from P to any other posi-
tion without depressing the brake pedal. If the shift lever can be shifted from P, there
may be a problem with the shift lock sy stem. Have the vehicle inspected by your
Lexus dealer immediately.Before driving the vehicle
When driving the vehicle
When parking the vehicle

378 6-1. Maintenance and care
RC F_U ■
Brake ●
Painted brake calipers (if equipped)
• When using detergent, use ne utral detergent. Do not use hard brushes or abrasive
cleaners, as they will damage the paint.
• Do not use detergent on the brake calipers when they are hot.
• Wash detergent off immediately after use. ●
RC F: Rust may form if the vehicle is parked with wet brake pads or disc rotors, causing
them to stick. Before parking the vehicle af ter it is washed, drive slowly and apply the
brakes several times to dry the parts. ■
Bumpers
Do not scrub with abrasive cleaners. ■
Side windows water-repelle nt coating (if equipped)●
The following precautions can extend the effectiveness of the water-repellent coating.
• Remove any dirt, etc. from the side windows regularly.
• Do not allow dirt and dust to accumulate on the windows for a long period.
Clean the windows with a soft, damp cloth as soon as possible.
• Do not use wax or glass cleaners that co ntain abrasives when cleaning the windows.
• Do not use any metallic objects to remove condensation build up.●
When the water-repellent performance has become insufficient, the coating can be
repaired. Contact your Lexus dealer.
WARNING ■
When washing the vehicle
Do not apply water to the inside of the engine compartment. Doing so may cause the
electrical components etc. to catch fire. ■
When cleaning the windshield (vehicles with rain-sensing windshield wipers)
●
When the upper part of the windshield where the raindrop se nsor is located is
touched by hand ●
When a wet rag or similar is held close to the raindrop sensor ●
If something bumps against the windshield ●
If you directly touch the raindrop sensor bo dy or if something bumps into the raindrop
sensorSet the wipers to the intermittent windshield
wipers. (  P. 236)
If AUTO mode is selected, the wipers may
operate unexpectedly in the following situa-
tions, and may result in hands being caught or
other serious injuries and cause damage to the
wiper blades.