warning light LEXUS LS500H 2020 Repair Manual

2264-5. Using the driving support systems
■If the PCS warning light illuminates and
a message is displayed on the
multi-information display
The system may be temporarily unavailable
or may be malfunctioning.
When driving on highways and free-
ways with white (yellow) lane lines, this
function alerts the driver when the
vehicle might depart from its lane or
course
* and provides assistance by
operating the steering wheel to keep
the vehicle in its lane or course
*. Fur-
thermore, the system provides steering
assistance when dynamic radar cruise
control with full-speed range is operat-
ing to keep the vehicle in its lane and
when changing lanes (vehicles with
Lexus Safety System + A).
The LTA system recognizes white (yel-
low) lane lines or a course
* using the
front camera. Additionally, it detects
preceding and surrounding vehicles
(vehicles with Lexus Safety System +
A) using the front camera and radar.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
LTA (Lane Tracing Assist)
Summary of function

2274-5. Using the driving support systems
4
Driving
WARNING
■Before using LTA system
●Do not rely solely upon the LTA sys-
tem. The LTA system does not auto-
matically drive the vehicle or reduce
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 pay-
ing careful attention to the surround-
ing conditions and operating the
steering wheel to correct the path of
the vehicle. Also, the driver must take
adequate breaks when fatigued, such
as from driving for a long period of
time.
●Failure to perform appropriate driving
operations and pay careful attention
may lead to an accident, resulting in
death or serious injury.
●When not using the LTA system, use
the LTA switch to turn the system off.
■Situations unsuitable for LTA system
In the following situations, use the LTA
switch to turn the system off. Failure to do
so may lead to an acc ident, resulting in
death or serious injury.
●Vehicle is driven on a road surface
which is slippery due to rainy weather,
fallen snow, freezing, etc.
●Vehicle is driven on a snow-covered
road.
●White (yellow) lines are difficult to see
due to rain, snow, fog, dust, etc.
●Vehicle is driven in a temporary lane or
restricted lane due to construction
work.
●Vehicle is driven in a construction
zone.
●A spare tire, tire chains, etc. are
equipped.
●When the tires have been excessively
worn, or when the tire inflation pres-
sure is low.
●When tires of a size other than speci-
fied are installed.
●Vehicle is driven in traffic lanes other
than that highways and freeways.
●During emergency towing.
■Situations in whic h the lane change
assist function should not be used
●When driving on a one lane road or
road without lane markers
●When there is no broken white line
between your vehicle and the lane
toward which the turn signal is oper-
ated
■Preventing LTA system malfunctions
and operations performed 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, contact 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 repairs, con-
tact your Lexus dealer.
■Conditions in which functions may
not operate properly
In the following situations, the functions
may not operate properly and the vehicle
may depart from its la ne. Drive safely by
always paying careful attention to your
surroundings and operate the steering
wheel to correct the path of the vehicle
without relying solely on the functions.

2294-5. Using the driving support systems
4
Driving
■Lane departure alert function
When the system determines that the
vehicle might depart from its lane or
course
*, a warning is displayed on the
multi-information display, and either a
warning buzzer will sound or the steer-
ing wheel will vibrate to alert the driver.
When the warning buzzer sounds or the
steering wheel vibrates, check the area
around your vehicle and carefully operate
the steering wheel to move the vehicle
back to the center of the lane.
Vehicle with BSM: When the system deter-
mines that the vehicle might depart from its
lane and that the po ssibility of a collision
with an overtaking vehicle in the adjacent
lane is high, the lane departure alert will
operate even if the turn signals are operat-
ing.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
WARNING
●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 sur-
face, such as concrete.
●If the edge of the road is not clear or
straight.
●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 oncom-
ing vehicle, the sun, etc. enters the
camera.
●The vehicle is driven on a slope.
●The vehicle is driven on a road which
tilts left or right, or a winding road.
●The vehicle is driven on an unpaved or
rough road.
●The traffic lane is excessively narrow
or wide.
●The vehicle is extremely tilted due to
carrying 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 amount due to road conditions
during driving (poor roads or road
seams).
●When driving in a tunnel or at night
with the headlights off or when a head-
light is dim due to its lens being dirty or
it being misaligned.
●The vehicle is struck by a crosswind.
●The vehicle is affected by wind from a
vehicle driven in a nearby lane.
●The vehicle has just changed lanes
through operation of the steering
wheel by the driver or crossed an
intersection.
●Tires which differ by structure, manu-
facturer, brand or tread pattern are
used.
●Snow tires, etc. are equipped.
●The vehicle is being driven at
extremely high speeds.
Functions included in LTA system

2354-5. Using the driving support systems
4
Driving
*1: The function operates even if the vehi-cle speed is less than approximately 32
mph (50 km/h) when the lane center-
ing function is operating.
*2: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
●Steering assist function
This function operates when all of the fol-
lowing conditions are me t in addition to the
operation conditions for the lane depar-
ture alert function.
•Setting for “Steering Assist” in of the
multi-information display is set to “ON”.
( P.80)
• Vehicle is not accelerated or decelerated by a fixed amount or more.
• Steering wheel is not operated with a steering force level su itable for changing
lanes.
• ABS, VSC, TRAC and PCS are not oper- ating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not
displayed. ( P.237)
●Vehicle sway warning function
This function operates when all of the fol-
lowing conditions are met.
• Setting for “Sway Warning” in of the multi-information display is set to “ON”.
( P.80)
• Vehicle speed is approximately 32 mph (50 km/h) or more.
• Width of traffic lane is approximately 9.8
ft. (3 m) or more.
• No system malfunctions are detected. ( P.238)
●Lane centering function
This function operates when all of the fol-
lowing conditions are met.
• LTA is turned on.
• Setting for “Steering Assist” and “Lane Center” in of the multi-information
display are set to “ON”. ( P.80)
• This function recognizes white (yellow) lane lines or the position of a preceding
vehicle (except when the preceding vehi-
cle is small, such as a motorcycle).
• The dynamic radar cruise control with full-speed range is operating in vehi-
cle-to-vehicle distance control mode.
• Width of traffic lane is approximately 10
to 13 ft. (3 to 4 m).
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. ( P.238)
• Vehicle does not ac celerate or deceler-
ate by a fixed amount or more.
• Steering wheel is not operated with a
steering force level su itable for changing
lanes.
• ABS, VSC, TRAC and PCS are not oper-
ating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. ( P.237)
• The driver has one or both hands on the steering wheel. (vehicles with Lexus
Safety System + A)
• The vehicle is being driven in the center of a lane.
• Steering assist function is not operating.
●Lane change assist fu nction (vehicles with
Lexus Safety System + A)
This function will operate when all of the
following conditions are met:
• The lane centering function is operating.
• “Lane Change Assist” is set to “ON” in of the multi-information dis-
play.( P.80)
• The vehicle speed is between approxi- mately 57 and 85 mph (90 and 140
km/h).
• White (yellow) lane lines are detected by
the system.
• A broken white line is detected between your vehicle and the lane toward which
the turn signal is operated.
• The turn signal lever is held partway (lane change position) for approximately 1 sec-
ond.
• A vehicle is not overtaking your vehicle
or detected in the lane toward which the
turn signal is operated.
• The vehicle is being driven straight or
around a slight curve.
• The vehicle is not a ccelerating or decel-
erating more than a certain amount.
• The steering wheel is not being turned sufficiently to perf orm a lane change.

2374-5. Using the driving support systems
4
Driving
●When the vehicle speed is outside of the
operational range of the function
●When the system detects operation of
the steering wheel, brake or accelerator
pedal by the driver
While the lane change assist function is
operating, if the system detects that a vehi-
cle is quickly approaching in the lane
toward which the turn signal is operated,
the steering assist may slightly steer the
vehicle away from the lane while a buzzer is
sounding, the steering wheel is vibrating,
and a warning display is displayed on the
multi-information display, to help prevent
the vehicle from entering the lane and alert
the driver of the approaching vehicle.
■Hands off steering wheel warning
In the following situations, a warning mes-
sage urging the driver to hold the steering
wheel and the symbol shown in the illustra-
tion are displayed on the multi-information
display to warn the driver. The warning
stops when the system determines that the
driver holds the steering wheel. Always
keep your hands on the steering wheel
when using this system, regardless of warn-
ings.
Depending on the vehicle condition and
road conditions, the warning may not oper-
ate. Also, if the system determines that the
vehicle is driving around a curve, warnings
will occur earlier than during straight-lane
driving.
●When the system determines that the
driver is driving without holding the steer-
ing wheel while the sy stem is operating
If the driver continue s to keep their hands
off of the steering wheel, the buzzer
sounds, the driver is warned and the func-
tion is temporarily ca nceled. This warning
also operates in the same way when the driver continuously operates the steering
wheel only a small amount.
The buzzer also sounds even if the alert
type is set to .
●When the system determines that the
vehicle may not turn and instead depart
from its lane while driving around a curve
(vehicles with Lexus Safety System + 2.0)
●When the system determines that the
driver is driving with
out holding the steer-
ing wheel while the st eering wheel assist
of the steering assist function is operating
(vehicles with Lexus Safety System + 2.0)
If the driver continues to keep their hands
off of the steering wheel and the steering
wheel assist is operating, the buzzer
sounds and the driver is warned. Each time
the buzzer sounds, the continuing time of
the buzzer becomes longer.
The buzzer also sounds even if the alert
type is set to .
In situations such as the following, the sys-
tem may not be able to detect when the
driver’s hands are on the steering wheel
(vehicles with Lexus Safety System + A):
●If a steering wheel cover is installed.
●If the driver is wearing gloves.
●If something is attached to the steering
wheel.
●If the driver is gripping the wood trim,
stitched area, spokes, or other part of the
steering wheel that does not have sen-
sors.
In situations such as the following, the hands
off steering wheel alert may not operate
and the steering assist function and lane
centering function may operate even if the
driver’s hands are off the steering wheel
(vehicles with Lexus Safety System + A):
●If an object contacts the steering wheel.
●If a wide object or ar ms are held in front
of the steering wheel.
■Vehicle sway warning function
When the system determines that the vehi-

2444-5. Using the driving support systems
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears
When a vehicle is detected running ahead of you, the system automatically decelerates
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). The sy stem 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 th e system cannot decelerate sufficiently to
prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehi cle will also stop (vehicle is stopped by sys-
tem control). After the vehicle ahead starts off, pressing the “+RES” switch or depressing
the accelerator pedal (start-off operation) will resume follow-up cruising. If the start-off
operation is not performed, system contro l continues to keep your vehicle stopped.
When the turn signal lever is operated and your vehicle moves to a left lane while driving at
50 mph (80 km/h) or more, the vehicle will quickly accelerate to help to overtake a pass-
ing vehicle.
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 re ached. The system then returns to constant
speed cruising.
1 Press the cruise control main switch
to activate the cruise control.
Dynamic radar cruise control indicator will
come on and a message will be displayed
on the multi-information display. Press the
switch again to deactivate the cruise con-
trol.
If the cruise control ma in switch is pressed
and held for 1.5 seconds or more, the sys-
tem turns on in constant speed control mode. (
P.248)
2 Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 20 mph [30 km/h])
and press the “-SET” switch to set
the speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the
B
C
Setting the vehicle speed (vehi-
cle-to-vehicle distance control
mode)

2544-5. Using the driving support systems
Use the meter control switches to turn
on/off the function.
1
Press or to select .
2
Press or to select and
then press .
WARNING
●Keep the sensors and the surrounding
areas on the rear bumper clean at all
times.
If a sensor or its surrounding area on the
rear bumper is dirty or covered with
snow, the Blind Spot Monitor may not
operate and a warning message
(  P.252) will be displayed. In this situa-
tion, clear off the dirt or snow and drive
the vehicle with the operation conditions
of the BSM function ( P.256) satisfied
for approximately 10 minutes. If the
warning message does not disappear,
have the vehicle inspected by your Lexus
dealer.
●Do not attach accessories, stickers
(including transparent stickers), alumi-
num tape, etc. to a sensor or its sur-
rounding area on the rear bumper.
●Do not subject a sensor or its sur-
rounding area on the rear bumper to a
strong impact.
If a sensor is moved even slightly off
position, the system may malfunction
and vehicles may not be detected cor-
rectly.
In the following situations, have your
vehicle inspected by your Lexus
dealer.
• A sensor or its surrounding area is subject to a strong impact.
• If the surrounding area of a sensor is scratched or dented, or part of them
has become disconnected.
●Do not disassemb le the sensor.
●Do not modify the sensor or surround-
ing area on the rear bumper.
●If a sensor or the rear bumper needs to
be removed/installed or replaced,
contact your Lexus dealer.
●Do not paint the rear bumper any
color other than an official Lexus color.
Turning the Blind Spot Monitor
on/off

2604-5. Using the driving support systems
When an object is detected, a graphic will
be displayed on the panoramic view moni-
tor (if equipped).
Use the meter control switches to
enable/disable the Lexus parking
assist-sensor. (P.81)
1
Press or to select .
2
Press or to select “PKSA”
and then press .
3
Press or to select and
then press .
When the intuitive parking assist func-
tion is disabled, the intuitive parking
assist OFF indicator ( P.68) illumi-
nates.
To re-enable the system when it was disabled, select on the multi-infor-
mation display, select and then On.
If disabled using this method, the sys-
tem will not be re-enabled by turning
the engine switch off and then to IGNI-
TION ON mode.
Turning intuitive parking assist
on/off
WARNING
■When using the intuitive parking
assist
Observe the following precautions.
Failing to do so may result in the vehicle
being unable to be driven safely and pos-
sibly cause an accident.
●Do not use the sensor at speeds in
excess of 6 mph (10 km/h).
●The sensors’ detection areas and reac-
tion times are limited. When moving
forward or reversin g, check the areas
surrounding the vehicle (especially the
sides of the vehicle) for safety, and
drive slowly, using the brake to control
the vehicle’s speed.
●Do not install accessories within the
sensors’ detection areas.
●The area directly under the bumpers is
not detected. Thin posts or objects
lower than the sensor may not be
detected when approached, even if
they have been detected once.
■When to disable the function
In the following situations, disable the
function as it may operate even though
there is no possibility of a collision.
●The vehicle is equipped with a fender
pole, wireless antenna or fog lights.
●The front or rear bumper or a sensor
receives a strong impact.
●A non-genuine Lexus suspension
(lowered suspension, etc.) is installed.
●Towing eyelets are installed.
●A backlit licence pl ate is installed.

2674-5. Using the driving support systems
4
Driving
■Outside rear view mirror indicator visi-
bility
In strong sunlight, the outside rear view mir-
ror indicator may be difficult to see.
■Hearing the RCTA buzzer
The RCTA buzzer may be difficult to hear
over loud noises, such as if the audio system
volume is high.
■When “RCTA Not Available” is shown
on the multi-information display
Water, snow, mud, etc., may be attached to
the rear bumper around the sensors.
(  P.254) Removing the water, snow, mud,
etc., from the attached to the rear bumper
around the sensors to normal.
Additionally, the function may not function
normally when used in extremely hot or
cold environments.
■Rear side radar sensors
 P.254
■Operation of the RCTA function
The RCTA function uses rear side radar sensors to detect vehicles approaching
from the right or left at the rear of the vehicle and alerts the driver of the presence
of such vehicles by flashing the outside rear view mirror indicators and sounding a
buzzer.
Approaching vehicles
Detection areas of approaching vehicles
■RCTA icon display
When a vehicle approaching from the right or left at the rear of the vehicle is
detected, the following will be dis-
WARNING
■Cautions regarding the use of the
function
The driver is solely responsible for safe
driving. Always driv e safely, taking care
to observe your surroundings.
The RCTA function is only a supplemen-
tary function which alerts the driver that a
vehicle is approaching from the right or
left at the rear of the vehicle. As the
RCTA function may not function cor-
rectly under certain conditions, the
driver’s own visual confirmation of safety
is necessary. Over reli ance on this func-
tion may lead to an accident resulting
death or serious injury.
NOTICE
■Before using the RCTA function
Do not place obstacles near the sensors.
RCTA function
A
B

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