parking brake LEXUS LS500H 2020 Service Manual

2854-5. Using the driving support systems
4
Driving
*: If equipped
This function will operate in situations such as the following if a vehicle is detected
in the traveling direction of the vehicle.
■When reversing, a vehicle is appr oaching and the brake pedal is not
depressed, or is depressed late
 P.253
Parking Support Brake function (rear-crossing vehicles)*
If a rear radar sensor detects a vehicle a pproaching from the right or left at the
rear of the vehicle and the system determ ines that the possibility of a collision
is high, this function will perform brake control to reduce the likelihood of an
impact with the approaching vehicle.
Examples of function operation
Types of sensors
WARNING
■To ensure the Parking Support Brake
(rear-crossing vehicles) can operate
properly
Observe the following precautions
regarding the rear side radar sensors
(
P.253). Failure to do so may cause a
sensor to not operate properly, and may
cause an accident.
●Do not modify, disassemble or paint
the sensors.
●Do not replace a rear side radar sen-
sor with a part other than a genuine
part.
●Do not damage the rear side radar
sensors, and always keep the radar
sensors and their surrounding area on
the bumper clean.

2864-5. Using the driving support systems
■The Parking Support Brake function
(rear-crossing vehicles) will operate
when
The function will operate when the PKSB
OFF indicator is not illuminated or flashing
(  P.69, 70) and all of the following condi-
tions are met:
●Engine output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 9 mph (15 km/h) or less.
• Vehicles which are approaching from the right or left at the rear of the vehicle at a
traveling speed of less than approxi-
mately 5 mph (8 km/h)
• The shift position is in R.
• The Parking Support Brake determines
that a stronger than normal brake opera-
tion is necessary to avoid a collision with
an approaching vehicle.
●Brake control
• Engine output restriction control is oper- ating.
• The Parking Support Brake determines
that an emergency brake operation is
necessary to avoid a collision with an
approaching vehicle.
■The Parking Support Brake function
(rear-crossing vehicles) will stop operat-
ing when
The function will stop operating if any of the
following conditions are met:
●Engine output restriction control
• The Parking Support Brake is disabled.
• The collision becomes avoidable with normal brake operation.
• A vehicle is no longer approaching from the right or left at the rear of the vehicle.
●Brake control
• The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed
since the vehicle was stopped by brake control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• A vehicle is no longer approaching from the right or left at the rear of the vehicle.
■Re-enabling the Parking Support Brake
function (rear-crossing vehicles)
 P.277
■Detection area of the Parking Support
Brake function (rear-crossing vehicles)
The detection area of the Parking Support
Brake function (rear-crossing vehicles) dif-
fers from the detection area of the RCTA
function ( P.268). Therefore, even if the
RCTA function detects a vehicle and pro-
vides an alert, the Parking Support Brake
function (rear-crossing vehicles) may not
start operating.
■Conditions under which the Parking
Support Brake function (rear-crossing
vehicles) will not detect a vehicle
The Parking Support Brake function
(rear-crossing vehicles) is not designed to
detect the following types of vehicles and/or
objects:
●Vehicles approaching from directly
behind
●Vehicles backing up in a parking space
next to your vehicle
●Vehicles that the sensors cannot detect
due to obstructions
●Vehicles which suddenly accelerate or
decelerate near your vehicle
●Guardrails, walls, signs, parked vehicles
and similar stationary objects
●Small motorcycles, bicycles, pedestrians,
etc.
WARNING
●If the area around a rear side radar
sensor is subjected to an impact, the
system may not operate properly due
to a sensor malfunct ion. Have the vehi-
cle inspected by your Lexus dealer.

2874-5. Using the driving support systems
4
Driving
●Vehicles moving away from your vehicle
●Vehicles approaching from the parking
spaces next to your vehicle
●Objects which are extremely close to a
radar sensor
●Vehicles which are approaching from the
right or left at the rear of the vehicle at a
traveling speed of less than approxi-
mately 5 mph (8 km/h)
●Vehicles which are approaching from the
right or left at the re ar of the vehicle at a
traveling speed of more than approxi-
mately 15 mph (24 km/h)
■PKSB buzzer
If the Parking Support Brake is enabled and
brake control is performed, a buzzer will
sound to notify the driver.
■Situations in which the system may
operate even though there is no possi-
bility of a collision
In some situations such as the following, the
Parking Support Brake function
(rear-crossing vehicles) may operate even
though there is no possibility of a collision.
●When the parking space faces a street
and vehicles are being driven on the
street
●When a detected vehicle turns while
approaching the vehicle
●When a vehicle passes by the side of your
vehicle
●When the distance between your vehicle
and metal objects, such as a guardrail,
wall, sign, or parked vehicle, which may
reflect electrical waves toward the rear of
the vehicle, is short
●When there are spinning objects near
your vehicle such as the fan of an air con-
ditioning unit
●When water is spla shed or sprayed
toward the rear bumper, such as from a
sprinkler
■Situations in which the Parking Support
Brake function (rear-crossing vehicles)
may not operate properly
In some situations, such as the following, the

2894-5. Using the driving support systems
4
Driving
*:If equipped
When a pedestrian is detected behind the vehicle while backing up, the brake
pedal is not depressed or is depressed late.
Displays a message to urge the driver
to take evasive action when a pedes-
trian is detected in the detection area
behind the vehicle. (A message will
also be displayed on the multi-informa-
tion display and head-up display (if
equipped).)Pedestrian detection icon
Brake reminder
Parking Support Brake function (rear pedestrians)*
If the rear camera sensor detects a pedestrian behind the vehicle while back-
ing up and the system determines that the possibility of colliding with the
detected pedestrian is high, a buzzer will sound. If the system determines that
the possibility of colliding with the dete cted pedestrian is extremely high, the
brakes will be applied automatically to he lp reduce the impact of the collision.
Examples of system operation
Center Display
A
B

2904-5. Using the driving support systems
■Parking Support Brake function (rear
pedestrians) will operate when
The function will operate when the PKSB
OFF indicator is not illuminated or flashing
(  P.69, 70) and all of the following condi-
tions are met:
●Engine output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 9 mph (15 km/h) or less.
• The shift position is in R.
• The rear camera sensor detects a pedes- trian behind the vehicle while backing up
and the system determines that the possi-
bility of colliding with the detected
pedestrian is high.
●Brake control
• Engine output restriction control is oper- ating. • The Parking Support Brake determines
that an emergency brake operation is
necessary to avoid a collision with a
pedestrians.
■The Parking Support Brake function
(rear pedestrians) will stop operating
when
The function will stop operating if any of the
following conditions are met:
●Engine output restriction control
• The Parking Support Brake is disabled.
• The collision becomes avoidable with
normal brake operation.
• The pedestrian is no longer detected
behind your vehicle.
●Brake control
• The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed since the vehicle was stopped by brake
control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• The pedestrian is no longer detected behind your vehicle.
■Re-enabling the Parking Support Brake
function (rear pedestrians)
 P.277
■Detection area of the Parking Support
Brake function (rear pedestrians)
The detection area of the Parking Support
Brake function (rear pedestrians) differs
from the detection area of the RCD func-
tion ( P.271). Therefore, even if the RCD
function detects a pedestrian and provides
an alert, the Parking Support Brake function
(rear pedestrians) may not start operating.
■Situations in which the system may not
operate properly
●Some pedestrians, such as the following,
may not be detected by the Parking Sup-
port Brake function (rear pedestrians),
preventing the function from operating
properly:
• Pedestrians who are bending forward or
squatting
• Pedestrians who are lying down
• Pedestrians who are running
• Pedestrians who suddenly enter the detection area
• People riding a bicycle, skateboard, or
WARNING
■If the Parking Support Brake function
(rear pedestrians) operates unneces-
sarily
Depress the brake pedal immediately
after the Parking Support Brake function
(rear pedestrians) operates. (Operation
of the function is canceled by depressing
the brake pedal.)
■Correct use of the Parking Support
Brake function (rear pedestrians)
Do not overly rely on the Parking Sup-
port Brake function (rear pedestrians).
Depending on the road conditions, vehi-
cle conditions and weather, this function
may not operate correctly. As the detec-
tion performance of the rear camera is
limited, always drive safely, taking care to
observe your surroundings.
Additionally, if the PKSB OFF indictor is
flashing or a warning message is dis-
played on the center display indicating
that the Parking Support Brake function
(rear pedestrians) is unavailable, the
function cannot be used. Even if these
warnings are not output, the driver is
always responsible for paying attention
to the vehicle’s surro undings and driving
safely.

2914-5. Using the driving support systems
4
Driving
other light vehicle
• Pedestrians wearing oversized clothing such as a rain coat, long skirt, etc., making
their silhouette obscure
• Pedestrians whose body is partially hid- den by an object, such as a cart or
umbrella
• Pedestrians which are obscured by dark- ness, such as at night
●In some situations, such as the following,
pedestrians may not be detected by the
Parking Support Brake function (rear
pedestrians), preventing the function
from operating properly:
• When backing up in inclement weather (rain, snow, fog, etc.)
• When the rear camera is obscured (dirt,
snow, ice, etc. are attached) or scratched
• When a very bright light, such as the sun, or the headlights of another vehicle,
shines directly into the rear camera
• When backing up in a place where the surrounding brightness changes sud-
denly, such as at the entrance or exit of a
garage or underground parking lot
• When backing up in a dim environment
such as during dusk or in an underground
parking lot
●Even though there are no pedestrians in
the detection area, some objects, such as
the following, may be detected, possibly
causing the Parking Support Brake func-
tion (rear pedestri ans) to operate.
• Three dimensional objects, such as a
pole, traffic cone, fence, or parked vehi-
cle
• Moving objects, such as a car or motor-
cycle
• Objects moving toward your vehicle when backing up, such as flags or pud-
dles (or airborne matter, such as smoke,
steam, rain, or snow)
• Cobblestone or gravel roads, tram rails,
road repairs, white lines, pedestrian
crossings, puddles or fallen leaves on the
road
• Metal covers (gratings), such as those
used for drainage ditches
• Objects reflected in a puddle or on a wet road surface
• The roadside or bumps on the road
•Shadows on the road
●In some situations, such as the following, the Parking Support Brake function (rear
pedestrians) may operate even though
there are no pedestrians in the detection
area.
• When backing up toward the roadside or a bump on the road
• If the vehicle is signif icantly tilted, such as
when carrying a heavy load
• When backing up toward an
incline/decline
• If the suspension has been modified or tires of a size othe r than specified are
installed
• If the rear of the vehicle is raised or low- ered due to the carried load
• If an electronic component, such as a backlit license plate or rear fog light, is
installed near the rear camera
• If a bumper protector, such as an addi- tional trim strip, is installed to the rear
bumper
• If the orientation of the rear camera has been changed
• If a towing eyelet is in stalled to the rear of
the vehicle
• When water is flowing over the rear cam- era lens
• When the rear camera is obscured (dirt,
snow, ice, etc. are at tached) or scratched
• If there is a flashing light in the detection
area, such as the emergency flashers of
another vehicle

2994-5. Using the driving support systems
4
Driving
■When the TRAC/VSC systems are
operating (vehicles without Lexus
Safety System + A)
The slip indicator light will flash while the
TRAC/VSC systems are operating.
■When the TRAC/VSC/ABS systems are
operating (vehicles with Lexus Safety
System + A)
The slip indicator light will flash while the
TRAC/VSC/ABS systems are operating.
■Disabling the TRAC system
If the vehicle gets stuck in mud, dirt or snow,
the TRAC system may reduce power from
the engine to the wheels. Pressing the
switch to turn the system off may make it
easier for you to rock the vehicle in order to
free it.
To turn the TRAC system off, quickly press
and release the switch.
The “Traction Control Turned Off” will be
shown on the multi-information display.
Press the switch again to turn the sys-
tem back on.
■Disabling both TRAC and VSC systems
To turn the TRAC and VSC systems off,
press and hold the switch for more
than 3 seconds while the vehicle is stopped.
The VSC OFF indicator light will come on
and the “Traction Control Turned Off” will
be shown on the multi-information display.
*
Press the switch ag ain to turn the sys-
tem back on.
*: On vehicles with PCS (Pre-Collision System), PCS will also be disabled (only
Pre-Collision warning is available). The
PCS warning light will come on and a
message will be di splayed on the
multi-information display. ( P.215,
223)
■When the message is displayed on the
multi-information display showing that
TRAC has been disabled even if the
switch 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 position is in a position other
than P or N (when stating off for-
ward/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

3004-5. Using the driving support systems
of the following situations:
●Shift the shift position 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
■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 dis-
abled 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. How-
ever, the position will return to normal after
VGRS is reactivated.
■When the battery is disconnected (vehi-
cles with VGRS)
The steering wheel may move from its
straight forward position, but this will be
corrected automatically when driving.
■Sounds and vibrations caused by the
ABS, brake assist, VS C, 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
systems.
●Any of the following conditions may
occur when the above systems are oper-
ating. None of these indicates that a mal-
function 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.
• Vehicles without Lexus Safety System +
A: The brake pedal may pulsate slightly after the ABS is activated.
• Vehicles without Lexus Safety System + A: The brake pedal may move down
slightly after the ABS is activated.
■ECB operating sound
ECB operating sound may be heard in the
following cases, but it does not indicate that
a malfunction has occurred.
●Operating sound heard from the engine
compartment when the brake pedal is
operated.
●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 engine.
■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.
■Automatic reactivation of TRAC and
VSC systems
After turning the TRAC and VSC systems
off, the systems will be automatically
re-enabled in the following situations:
●When the engine 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, automatic re-enabling will not
occur when vehicle speed increases.
■Reduced effectiveness of the EPS sys-
tem
The effectiveness of the EPS system is
reduced to prevent the system from over-
heating when there is frequent steering
input over an extended period of time. The
steering wheel may feel heavy as a result.
Should this occur, re frain from excessive
steering input or stop the vehicle and turn
the engine off. The EPS system should
return to normal within 10 minutes.
■Secondary Collision Brake operating
conditions
The vehicle speed is approximately 6 mph

3014-5. Using the driving support systems
4
Driving
(10 km/h) or more and the airbag sensor
detects a collision. (The Secondary Colli-
sion Brake will not operate when the vehicle
speed is below approximately 6 mph [10
km/h].)
■Secondary Collision Brake automatic
cancellation
The Secondary Collision Brake is automati-
cally canceled in the following situations:
●The vehicle speed drops below approxi-
mately 6 mph (10 km/h)
●A certain amount of time elapses during
operation
●The accelerator pedal is depressed a
large amount
■When “Check VGRS System” or
“CHECK DRS” is displayed on the
multi-information display
The VGRS or DRS may not operate prop-
erly. Have the vehicle inspected by your
Lexus dealer.
WARNING
■The ABS does not operate effectively
when
●The limits of tire gripping performance
have been exceeded (such as exces-
sively 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
vehicle’s stopping di stance. Always main-
tain a safe distance from the vehicle in
front of you, especially in the following
situations:
●When driving on dirt, gravel 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/VSC may not operate effec-
tively when
Directional control and power may not
be achievable while driving on slippery
road surfaces, even if the TRAC/VSC
system is operating. Drive the vehicle
carefully in conditions where stability and
power may be lost.
■Hill-start assist control does not oper-
ate 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 control is not intended to hold
the vehicle stationary for an extended
period of time. Do not attempt to use
hill-start assist control to hold the vehi-
cle on an incline, as doing so may lead
to an accident.
■When the TRAC/VSC is activated
(vehicles without Lexus Safety Sys-
tem + A)
The slip indicator light flashes. Always
drive carefully. Reckless driving may
cause an accident. Exercise particular
care when the indicator light flashes.
■When the TRAC/ABS/VSC is acti-
vated (vehicles with Lexus Safety Sys-
tem + A)
The slip indicator light flashes. Always
drive carefully. Reckless driving may
cause an accident. Exercise particular
care when the indicator light flashes.
■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.

3044-6. Driving tips
Perform the following according to the
driving conditions:
Do not try to forcib ly open a window
or move a wiper that is frozen. Pour
warm water over the frozen area to
melt the ice. Wipe away the water
immediately to prevent it from
freezing.
 To ensure proper operation of the
climate 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 accumu-
lated on the exterior lights, vehicle’s
roof, chassis, 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
safe distance between you and the
vehicle ahead, and drive at a reduced
speed suitable to road conditions. Park the vehicle and shift the shift posi-
tion 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.
Vehicles with front and rear tires of
the same size
Use the correct tire chain size when
mounting the tire chains.
Chain size is regulated for each tire
size.
Side chain (0.12 in. [3 mm] in diam-
eter)
Cross chain (0.16 in. [4 mm] in
diameter)
Vehicles with front and rear tires of
differing sizes
Tire chains cannot be mounted.
Snow tires should be used instead.
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow
tires from Lexus dealers or legitimate tire
retailers.
This is because the removal and attach-
ment of snow tires affects the operation
of the tire pressure warning valves and
transmitters.
Before driving the vehicle
When driving the vehicle
When parking the vehicle
Selecting tire chains
A
B