warning light LEXUS LS500 2021 Repair Manual

2384-5. 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.
While driving on a road with clear
white (yellow) lane lines, the LTA sys-
tem warns the driver if the vehicle may
deviate from the current lane or
course
*, and also can slightly operate
the steering wheel to help avoid devia-
tion from the lane or course
*. Also,
while the dynamic radar cruise control
with full-speed range is operating, this
system will operate the steering wheel
to maintain the vehicle’s lane position
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

2394-5. 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.
●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
●Vehicle is driven in traffic lanes other
than that freeways and highways.
■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.

2414-5. 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 or
crossed an intersection.
●Tires which differ by structure, manu-
facturer, brand or tread pattern are
used.
●When tires of a size other than speci-
fied are installed.
●Snow tires, etc. are equipped.
●The vehicle is being driven at
extremely high speeds.
Functions included in LTA system

2474-5. 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.82)
• 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.249)
●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.82)
• 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.250)
●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.82)
• 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.250)
• 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.249)
• 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.82)
• 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.

2484-5. Using the driving support systems
• 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.249)
• The dynamic radar cruise control with
full-speed range approach warning is not
operating.
• The lane departure alert function is not
operating.
• The curve speed reduction function ( P.260) is not operating.
■Temporary cancelation of functions
●When operation conditions are no longer
met, a function may be temporarily can-
celed. However, when the operation con-
ditions are met again, operation of the
function is automa tically restored.
(  P.246)
●If the operation conditions ( P.246) are
no longer met while the lane centering
function is operating, the steering wheel
may vibrate and the buzzer may sound to
indicate that the function has been tem-
porarily canceled. However, if the “Alert”
customization setting is set to ,
the system will notify the driver by vibrat-
ing the steering wheel instead of sound-
ing the buzzer.
●If the operating conditions ( P.246) are
no longer met, the buzzer may sound to
indicate that the lane change assist func-
tion has been temporarily canceled.
(vehicles with Lexus Safety System + A)
■Steering assist function/lane centering
function
●Depending on the vehicle speed, lane
departure situation, road conditions, etc.,
the driver may not feel the function is
operating or the function may not oper-
ate at all.
●Even if the curve speed reduction func-
tion ( P.260) operates, the lane center-
ing function may not be able to drive the
vehicle around a curve successfully.
(vehicles with Lexus Safety System + A)
●The steering control of the function is
overridden by the driver’s steering wheel
operation.
●Do not attempt to test the operation of the steering assist function.
■Lane departure alert function
●The warning buzzer may be difficult to
hear due to external noise, audio play-
back, etc. Also, it may be difficult to feel
steering wheel vibrations due to the road
conditions, etc.
●If the edge of the course* is not clear or
straight, the lane departure alert function
may not operate.
●Vehicle with BSM: It may not be possible
for the system to determine if there is a
danger of a collision with a vehicle in an
adjacent lane.
●Do not attempt to test the operation of
the lane departure alert function.
*: Boundary between asphalt and the side
of the road, such as grass, soil, or a curb
■Lane change assist function (vehicles
with Lexus Safety System + A)
Depending on the vehicle speed, vehicle
condition, road conditions, or conditions of
the area around the vehicle, the lane
change assist function may not operate or it
may be difficult to recognize that it has
operated.
If steering control oper ation is excessive or
insufficient, it can be corrected by the
driver’s operation of the steering wheel.
In situations such as the following, the lane
change assist function may be canceled:
●When the system no longer detects white
(yellow) lane lines
●When the turn signal lever is operated
fully (right/left turn position)
●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 la ne while a buzzer is
sounding, the steering wheel is vibrating,

2574-5. Using the driving support systems
4
Driving
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 system 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 yo ur vehicle moves to an overtaking lane while
driving at 50 mph (80 km/h) or more, the vehicle will accelerate to help to overtake a
passing vehicle.
The system’s identification of what is an over taking lane may be determined solely based on
the location of the steering wheel in the vehicl e (left side driver position versus right side
driver position.) If the vehicle is driven to a re gion where the overtaking lane is on a different
side from where the vehicle is normally driven, the vehicle may accelerate when the turn
signal lever is operated in the opposite direction to the overtaking lane (e.g., if the driver
normally operates the vehicle in a region where the overtaking lane is to the right but then
drives to a region where the overtaking lane is to the left, the vehicle may accelerate when
the right turn signal is activated).
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.261)
2 Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
B
C
Setting the vehicle speed (vehi-
cle-to-vehicle distance control
mode)

2684-5. Using the driving support systems
Use the meter control switches to turn
on/off the function.
1Press or to select .
2 Press or to select and
then press .
When the BSM function is disabled, the
BSM OFF indicator illuminates. (Each time
the engine switch is turned off then
changed to IGNITION ON mode, the
Blind Spot Monitor will be enabled auto-
matically.)
■Vehicles that can be detected by the Blind Spot Monitor
The Blind Spot Monitor uses rear side radar sensors to detect the following vehi-
cles traveling in adjacent lanes and advises the driver of the presence of such vehi-
cles via the indicators on th e outside rear view mirrors.
Vehicles that are traveling in areas that are not visible using the outside rear
view mirrors (the blind spots)
WARNING
●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
Blind Spot Monitor operation
A

2744-5. Using the driving support systems
■The system can be operated when
●The engine switch is in IGNITION ON
mode.
●Intuitive parking assist function is on.
●The vehicle speed is less than about 6
mph (10 km/h).
●A shift position other than P is selected.
■Setting the buzzer volume
The buzzer volume can be adjusted on the
multi-information display. ( P.271)
■If “Clean Parking Assist Sensor” is dis-
played on the multi-information display
A sensor may be covered with water drops,
ice, snow, dirt, etc. Remove the water drops,
ice, snow, dirt, etc., from the sensor to return
the system to normal.
If a sensor is dirty, the position of the dirty
sensor will be shown on the display.
Due to ice forming on a sensor at low tem-
peratures, a warning message may be dis-
played or the sensor may not be able to
detect an object. Once the ice melts, the
system will return to normal.
■If “Parking Assist Unavailable” is dis-
played on the multi-information display
Water may be continuous ly flowing over the
sensor surface, such as in a heavy rain.
When the system determines that it is nor-
mal, the system will return to normal.
WARNING
●The area directly under the bumpers is
not detected. Thin posts or objects
lower than the sensor may not be
detected when appr oached, 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 bu mper 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.
■When using intuitive parking assist
In the following situations, the system
may not function correctly due to a sen-
sor malfunction, etc. Have the vehicle
checked by your Lexus dealer.
●The intuitive parking assist operation
display flashes or shows continuously,
and a buzzer sounds when no objects
are detected.
●If the area around a sensor collides
with something, or is subjected to
strong impact.
●If the bumper or grille collides with
something.
●If the display flashes or is displayed
continuously and a buzzer does not
sound, except when the mute function
has been turned on.
●If a display error occurs, first check the
sensor.
If the error occurs even when there is
no ice, snow or mud on the sensor, it is
likely that the sensor is malfunctioning.
■Notes when washing the vehicle
Do not apply intensive bursts of water or
steam to the sensor area.
Doing so may result in the sensor mal-
functioning.
●When using a high pressure washer to
wash the vehicle, do not spray the sen-
sors directly, as doing so may cause a
sensor to malfunction.
●When using steam to clean the vehicle,
do not direct steam too close to the
sensors as doing so may cause a sen-
sor to malfunction.

2784-5. Using the driving support systems
If a vehicle approaching from the right or
left at the rear of the vehicle is detected,
the RCTA icon (P.279) for the detected
side will be displayed on the Center Dis-
play. This illustration shows an example of a
vehicle approaching from both sides of the
vehicle.
RCTA buzzer
If a vehicle approaching from the right or
left at the rear of the vehicle is detected, a
buzzer will sound. The buzzer also sounds
for approximately 1 second immediately
after the RCTA function is turned on.
Use the meter control switches to
enable/disable the RCTA function.
(  P.83)
1 Press or to select .
2 Press or to select “PKSA”
and then press .
3 Press or to select “RCTA”
and then press .
When the RCTA function is disabled, the
RCTA OFF indicator ( P.70) illuminates.
(Each time the engine switch is turned off
then changed to IGNITION ON mode,
the RCTA function will be enabled auto-
matically.)
■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.267) 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.267
Turning the RCTA function
on/off
D
WARNING
■Cautions regarding the use of the
function
The driver is solely responsible for safe
driving. Always drive 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 certai n conditions, the
driver’s own visual confirmation of safety
is necessary. Over re liance 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.

3064-5. Using the driving support systems
■Turning 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 Cont rol Turned Off” will
be shown on the mult i-information display.
*
Press the switch again 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 displayed on the
multi-information display. ( P.227,
234)
■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 is temporary deactivated. If the infor-
mation continues to show, 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
●Engine switch is turned to IGNITION
ON mode
■Automatic system cancelation of
hill-start assist control
The hill-start assist control will turn off in any
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
●Engine switch is turned Off
■VGRS is disabled when
VGRS may stop operat ing 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, 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
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