warning Lexus GS450h 2016 Owner's Manual / LEXUS 2016 GS450H (OM30E99U) Service Manual

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■If the PCS warning light flashes and a warning message is displayed on the multi-infor-
mation display
The pre-collision system may be temporarily unavailable or there may be a malfunction
in the system.
●In the following situations, the warning light will turn off, the message will disappear and
the system will become operational when normal operating conditions return:
• When the radar sensor or camera sensor or the area around either sensor is hot, such as in the sun
• When the radar sensor or camera sensor or the area around either sensor is cold,
such as in an extremely cold environment
• When the radar sensor or front grille embl em is dirty or covered with snow, etc.
• If the camera sensor is obst ructed, such as when the hood is open or a sticker is
attached to the windshield near the camera sensor
●If the PCS warning light continues to flash or the warning message does not disappear,
the system may be malfunctioning. Have the vehicle inspected by your Lexus dealer
immediately.
■If VSC is disabled
●If VSC is disabled ( P. 269), the pre-collision brake assist and pre-collision braking
functions are also disabled.
●The PCS warning light will turn on and “VSC Turned Off Pre-Collision Brake System
Unavailable” will be displayed on the multi-information display.

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LKA (Lane-Keeping Assist)
When driving on highways and freeways with white or yellow lines, this function
alerts the driver when the vehicle might depart from its lane and provides assis-
tance by operating the steering wheel to keep the vehicle in its lane. Further-
more, the system also provides steering assistance when dynamic radar cruise
control with full-speed range is operating to keep the vehicle in its lane.
The LKA system recognizes visible
white or yellow lines with the camera
sensor on the upper portion of the front
windshield.
◆Lane departure alert function
When the system determines that
the vehicle might depart from its
lane, a warning is displayed on the
multi-information display, and either
the warning buzzer sounds
or the
steering wheel vibrates to alert the
driver.
When the warning buzzer sounds or
the steering wheel vibrates, check
the surrounding road situation and
carefully operate the steering wheel
to move the vehicle back to the cen-
ter within the white (yellow) lines.
: If equipped
Summary of functions
Functions included in LKA system

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◆Lane departure control function
When the system determines that
the vehicle might depart from its
lane, the system provides assistance
as necessary by operating the steer-
ing wheel in small amounts for a
short period of time to keep the
vehicle in its lane.
If the system detects that the steering
wheel has not been operated for a
fixed amount of time or the steering
wheel is not being firmly gripped, a
warning is displayed on the multi-
information display and the warning
buzzer sounds.
◆Ve h i c l e s w a y w a r n i n g
When the vehicle is swaying or
appears as if it may depart from its
lane multiple times, the warning
buzzer sounds and a message is dis-
played on the multi-information dis-
play to alert the driver.

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◆Lane centering function
This function is linked with radar
cruise control and provides the
required assistance by operating the
steering wheel to keep the vehicle in
its current lane.
When radar cruise control is not
operating, the lane centering func-
tion does not operate.
If the system detects that the steering
wheel has not been operated for a
fixed amount of time or the steering
wheel is not being firmly gripped, a
warning is displayed on the multi-
information display and the warning
buzzer sounds.
WA R N I N G
■Before using LKA system
Do not rely solely upon the LKA system. LKA is not a system which automatically
drives the vehicle or reduces 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 always paying careful attention to the surrounding conditions and operate the steer-
ing wheel to correct the path of the vehicle. Also, make sure to take adequate breaks
when fatigued, such as from driv ing for a long period of time.
Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury.

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●Ve h i c l e s w a y w a r n i n g
This function operates when all of the following conditions are met.
• Setting for “Sway Warning” in of the multi-information display is set to “On”.
(  P. 9 3 )
• 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. 2 4 0 )
●Lane centering function
This function operates when all of the following conditions are met.
• LKA is turned on.
• Setting for “Steering Assist” and “Lane Center” in of the multi-information
display are set to “On”. ( P. 9 3 )
• System recognizes white (yellow) lines.
• Dynamic radar cruise control with full-speed range is operating.
• Width of traffic lane is approximat ely 8.2 to 13.5 ft. (2.5 to 4.1 m).
• Turn signal lever is not operated.
• Vehicle is driven on a straight road or around a gentle curve with a radius of more
than approximately 656 ft. (200 m).
• No system malfunctions are detected. ( P. 2 4 0 )
• Vehicle does not accelerate or decelerate by a fixed amount or more.
• Steering wheel is not operated with a st eering force level suitable for changing
lanes.
• ABS, VSC, TRAC and PCS (Pre-Collision System) are not operating.
• TRAC or VSC is not turned off.
• Lane departure control function is not operating.
■Temporary cancellation of functions
When operation conditions are no longer me t, a function may be temporarily canceled.
However, when the operation conditions are met again, operation of the function is auto-
matically restored. ( P. 2 3 7 )
■Lane departure control function/lane centering function
Depending on the vehicle speed, lane depart ure situation, road conditions, etc., the
operation of the functions may not be reco gnized or the functions may not operate.
■Lane departure alert function
The warning buzzer may be difficult to hear due to external noise, audio playback, etc.
Also, it may be difficult to feel steering wheel vibrations due to the road conditions, etc.

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■Hands off steering wheel alert
When the system determines that the driver has removed their hands from the steering
wheel while the lane departure control function or lane centering function is operating, a
warning message is displayed on the multi- information display and the buzzer sounds.
■White (yellow) lines are only on one side of road
The LKA system will not operate for the side on which white (yellow) lines could not be
recognized.
■Conditions in which functions may not operate properly
In the following situations, the camera sensor may not detect white (yellow) lines and var-
ious functions may not operate normally.
●There are shadows on the road that run paralle l with, or cover, the white (yellow) lines.
●The vehicle is driven in an area without white (yellow) lines, such as in front of a tollgate
or checkpoint, or at an intersection, etc.
●The white (yellow) lines are cracked, “Botts’ dots”, “Raised pavement marker” or stones
are present.
●The white (yellow) lines cannot be seen or are difficult to see due to sand, etc.
●The vehicle is driven on a road surface that is wet due to rain, puddles, etc.
●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 brig ht surface, such as concrete.
●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 oncoming vehicle, the sun, etc., enters the camera.
●The vehicle is driven where the road diverges, merges, etc.
●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 vehicle is driven around a sharp curve.
●The traffic lane is excessively narrow or wide.
●The vehicle is extremely tilted due to carry ing 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 am ount due to road conditions during driv-
ing (poor roads or road seams).

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●The headlight lenses are dirty and emit a faint amount of light at night, or the beam axis
has deviated.
●The vehicle is struck by a crosswind.
●The vehicle has just changed lane s or crossed an intersection.
●Snow tires, etc., are equipped.
■Wa r n i n g m e s s a g e
Warning messages are used to indicate a syst em malfunction or to inform the driver of
the need for caution while driving. ( P. 4 0 6 )
■Customization
The following settings can be changed.
For how to change settings, refer to P. 491
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Adjust alert type
Steering control functionTurn steering wheel assistance on and off
Vehicle sway warningTurn function on and off
Adjust alert sensitivity
Lane centering functionTurn function on and off

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WA R N I N G
■Situations unsuitable for dynamic radar cruise control with full-speed range
Do not use dynamic radar cruise control wi th full-speed range in any of the following
situations.
Doing so may result in inappropriate speed control and could cause an accident result-
ing in death or serious injury.
●Roads where there are pedestrians, cyclists, etc.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered with rain, ice or snow
●On steep downhills, or where there are sudden changes between sharp up and down
gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to freeways and highways
●When weather conditions are bad enough that they may prevent the sensors from
detecting correctly (fog, snow, sandstorm, heavy rain, etc.)
●When there is rain, snow, etc. on the front surface of the radar sensor or camera sen-
sor
●In traffic conditions that require frequent repeated acceleration and deceleration
●When your vehicle is towing a trailer or during emergency towing
●When an approach warning buzzer is heard often

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Pulling the lever toward you cancels
the speed control.
The speed control is also canceled when
the brake pedal is depressed.
(When the vehicle has been stopped by
system control, depressing the brake
pedal does not cancel the setting.)
Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
However, when a vehicle ahead is not detected, cruise control does not resume when
the vehicle speed is approximately 25 mph (40 km/h) or less.
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehicle-
to-vehicle distance.
■Warnings may not occur when
In the following instances, warnings may not occur even when the vehicle-to-
vehicle distance is small.
●When the speed of the preceding vehicle matches or exceeds your vehicle
speed
●When the preceding vehicle is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●When depressing the accelerator pedal
Canceling and resuming the speed control
1
2
Approach warning (vehicle-to-vehicle distance control mode)

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■Automatic cancelation of constant speed control mode
Constant speed control mode is automatically canceled in the following situations:
●Actual vehicle speed is more than approximately 10 mph (16 km/h) below the set vehi-
cle speed.
●Actual vehicle speed falls below approximately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is turned off by pressing the VSC OFF switch.
●Pre-collision braking is activated.
If constant speed control mode is automatica lly canceled for any other reason, there may
be a malfunction in the system. Contact your Lexus dealer.
■Warning messages and buzzers for dynamic ra dar cruise control with full-speed range
Warning messages and buzzers are used to indicate a system malfunction or to inform
the driver of the need for caution while driving. If a warning message is shown on the
multi-information display, read the message and follow the instructions. ( P. 4 0 6 )
■When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the brake pedal
when deceleration of the system is insuff icient or operate the accelerator pedal when
acceleration is required.
As the sensor may not be able to correctly detect these types of vehicles, the approach
warning ( P. 248) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane
●Vehicles with small rear ends (traile rs with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.)