warning Lexus GS450h 2015 Workshop Manual

GS450h_OM_OM30F70U_(U)
2734-5. Using the driving support systems
4
Driving
■Lane departure warning function
●When the vehicle speed is approximately 30 mph (48 km/h) or
more
●When the lane width is more than approximately 9.8 ft. (3.0 m)
●When driving on a straight road or through a curve with a radius of
more than approximately 394 ft. (120 m)
■Lane keeping assist function
●When the vehicle speed is between approximately 45 and 112 mph
(72 and 180 km/h)
●When the vehicle-to-vehicle distance mode of the radar cruise
control is on, and the set vehicle speed is approximately 45 mph
(72 km/h) or more (the function will not operate when the radar
cruise control is in set speed mode)
●When the lane width is between approximately 9.8 and 13.1 ft.
(3.0 and 4.0 m)
●When driving on a straight road or through a curve with a radius of
more than approximately 656 ft. (200 m)
Operating conditions for each function
GS450h_OM_OM30F70U_(U).book Page 273 Monday, January 19, 2015 9:34 AM

274
GS450h_OM_OM30F70U_(U)
4-5. Using the driving support systems
When the LKA system is on, the lane line display and steering wheel dis-
play are shown.Lane keeping assist function
operation indication
Steering wheel displayed:
Indicates that the function is currently
operating. (If the lane departure warn-
ing operates at this time, the steering
wheel flashes orange.)
Steering wheel not displayed:
Indicates that the function is not cur-
rently operating. (When the lane
keeping assist function is canceled,
the buzzer will beep twice.)
Dynamic radar cruise control dis-
play
Lane departure warning function
indication (when the inside of the
white line is white):
The function has recognized lane
markers. (If the lane departure warn-
ing operates at this time, the lines flash
orange.)
Lane departure warning function
indication (when the inside of the
white line is black):
A lane marker is not recognized by
the system, or the LKA system func-
tions are temporarily canceled.
Indication on the multi-information display
1
2
3
4
GS450h_OM_OM30F70U_(U).book Page 274 Monday, January 19, 2015 9:34 AM

GS450h_OM_OM30F70U_(U)
2754-5. Using the driving support systems
4
Driving
■Temporary cancelation of the LKA system functions
If any of the following occurs, the LKA system functions will be temporarily canceled.
The functions will resume after the necessary operating conditions have returned.
●The steering wheel is turned as far as necessary to cause the vehicle to change
lanes.
●When the system detects no-handed driving. (The lane keeping assist function will
be temporarily canceled, but the lane departure warning function will continue.)
●The turn signal lever is operated.
●The vehicle speed deviates from the operating range of the LKA system functions.
(The buzzer will beep twice when the lane keeping assist function is being can-
celed.)
●When the lane lines cannot be recognized while driving. (The buzzer will beep
twice when the lane keeping assist function is being canceled.)
●The wiper switch is set on high speed mode or is set on AUTO mode with wipers
operating at high speed. (The lane keeping assist function will be temporarily can-
celed, but the lane departure warning function will continue.)
●If the vehicle crosses a line for approximately half a minute or more. (The lane keep-
ing assist function will be temporarily canceled, but the lane departure warning
function will continue.)
●When the lane departure warning function is activated.
The lane departure warning function will not operate again for a several seconds
after it has been activated, even if the vehicle leaves the lane again.
■The lane departure warning
It may be difficult to feel the sensory warning depending on the road conditions.
■No-handed driving warning
If the steering wheel is not operated for approximately 15 seconds on a straight road
or approximately 5 seconds on a curve, the buzzer will beep twice, indicators on the
multi-information display will flash, and the lane keeping assist function will be tem-
porarily canceled. If you drive the vehicle with your hands lightly touching the steer-
ing wheel, this may also be detected as no-handed driving.
■After the vehicle has been parked in the sun
The LKA system functions may not be available and a warning message (→P. 5 2 6 )
will be displayed for a while after driving has started. In such cases, turn the LKA sys-
tem off and turn it on again after normal temperature returns. When the temperature
in the cabin decreases and the temperature around the camera sensor ( →P. 2 7 0 )
becomes suitable for its operation, the functions will begin to operate.
GS450h_OM_OM30F70U_(U).book Page 275 Monday, January 19, 2015 9:34 AM

276
GS450h_OM_OM30F70U_(U)
4-5. Using the driving support systems
■If there are lane markers on only one side of the vehicle
The lane keeping assist function will not operate. Also, the lane departure warning
will not operate for the side on which lane markers could not be recognized.
■Conditions in which the function may not operate correctly
In the following conditions, the LKA system functions may not operate, or it may not
be possible to ensure adequate performance. Also, the camera sensor may be
unable to recognize lane lines causing the lane departure warning function to oper-
ate incorrectly, or the lane keeping assist function may not operate properly. How-
ever, this does not indicate a malfunction.
●When driving through an area with no lane markers, such as a tollbooth, a crossing
or before a ticket checkpoint
●When driving on a sharp curve
●When lanes are extremely narrow or extremely wide
●When the vehicle leans to one side an unusual amount due to a heavy load or
improper tire inflation pressure
●When the following distance between your vehicle and the vehicle ahead is
extremely short
●When the lane markers are yellow (These may be more difficult for the system to
recognize compared to white markers.)
●When the lane markers are broken, “Botts’ dots”, “Raised pavement marker” or
stones
●When lane markers are obscured or partially obscured by sand, dirt, etc.
●When there are shadows on the road running parallel with lane markers, or if a
shadow covers the lane markers
●When driving on a particularly bright road surface, such as concrete
●When driving on a road surface that is bright due to reflected light
●When driving in a location where the light level changes rapidly, such as the
entrance to or exit from a tunnel
●When sunlight or the headlights of oncoming vehicles are shining directly into the
camera lens
●When driving on roads that are branching or merging
●When driving on a road surface that is wet due to rain, previous rainfall, standing
water, etc.
●When the vehicle experiences strong up-and-down motion such as when driving
on an extremely rough road or on a seam in the pavement
●When headlight brightness at nighttime is reduced due to dirt on the lenses, or
when the headlights are misaligned
●When driving with a strong crosswind
GS450h_OM_OM30F70U_(U).book Page 276 Monday, January 19, 2015 9:34 AM

GS450h_OM_OM30F70U_(U)
2774-5. Using the driving support systems
4
Driving
●When driving on winding roads or roads that are uneven
●When driving on rough or unpaved roads
■When changing the tires
Depending on the tires used, sufficient performance may not be maintainable.
■Warning messages for LKA
Warning messages are used to indicate a system malfunction or to inform the driver
of the need for caution while driving. (→P. 516, 526)
CAUTION
■Before using the LKA system
Do not rely solely on the LKA system. The LKA system does not drive the vehicle
automatically, nor does it reduce the amount of care you need to take. As such, the
driver must always assume full responsibility for understanding his/her surround-
ings, for operating the steering wheel to correct the driving line, and for driving
safely.
Inappropriate or negligent driving could lead to an accident.
■To avoid operating the LKA by mistake
Switch the LKA off using the “LKA” switch when not in use.
GS450h_OM_OM30F70U_(U).book Page 277 Monday, January 19, 2015 9:34 AM

288
GS450h_OM_OM30F70U_(U)
4-5. Using the driving support systems
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheat-
ing when there is frequent steering input over an extended period of time. The steer-
ing wheel may feel heavy as a result.
* Should this occur, refrain from excessive
steering input or stop the vehicle and turn the hybrid system off. The EPS system
should return to normal within 10 minutes.
*: If the LKA (Lane-Keeping Assist) system cannot operate in this case, a warning
message will be shown on the multi-information display.
CAUTION
■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 condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you, especially in the following situa-
tions:
●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 may not operate effectively when
Directional control and power may not be achievable while 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.
■When the VSC is activated
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 vehicl e stability and driving force, do not turn
the TRAC/VSC systems off unless necessary.
GS450h_OM_OM30F70U_(U).book Page 288 Monday, January 19, 2015 9:34 AM

290
GS450h_OM_OM30F70U_(U)
4-5. Using the driving support systems
PCS (Pre-Collision System)∗
◆Pre-collision seat belts (front seat only)
If the pre-collision sensor detects that a collision is unavoidable, the
pre-collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or
loses control of the vehicle. (→P. 3 4 )
◆Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.
◆Pre-collision braking
When there is a high possibility of a frontal collision, the system warns
the driver using a warning light, warning display and buzzer. If the sys-
tem determines that a collision is unavoidable, the brakes are automati-
cally applied to reduce the collision speed.
∗
: If equipped
When the radar sensor detects the possibility of a frontal collision, the
pre-collision system such as the brakes and seat belts are automatically
engaged to lessen impact as well as vehicle damage.
The pre-collision system can be turned on and off as necessary by oper-
ating the switch. ( →P. 2 9 2 )
GS450h_OM_OM30F70U_(U).book Page 290 Monday, January 19, 2015 9:34 AM

GS450h_OM_OM30F70U_(U)
2914-5. Using the driving support systems
4
Driving
◆Suspension control
When the system determines that there is a high possibility of a frontal
collision, the operation of AVS ( →P. 284) optimally controls the damp-
ing force of the shock absorber.
◆Steering control (if equipped)
XVehicles with VGRS
There is a high possibility of collision and if the steering wheel is oper-
ated, the steering gear ratio is changed by VGRS to help improve the
response to steering input.
XVehicles with LDH
There is a high possibility of collision and if the steering wheel is oper-
ated, the steering angles of the front and rear wheels and the heaviness
of the steering wheel are controlled by LDH, thus heightening respon-
siveness in response to the steering operation.
◆Driver monitor sy stem (if equipped)
When the system determines that there is a possibility of a collision, and
either the driver is not facing forward or the driver’s eyes are closed,
PCS warnings are given in advance to warn the driver. If the system
determines that the conditions to operate pre-collision alert braking
have been met even when the possibility of a collision increases further,
pre-collision alert braking will operate.
GS450h_OM_OM30F70U_(U).book Page 291 Monday, January 19, 2015 9:34 AM

292
GS450h_OM_OM30F70U_(U)
4-5. Using the driving support systems
Enabled
Disabled
The “PCS” warning light comes on
when pre-collision system is disabled.
Disabling pre-collision system
1
2
GS450h_OM_OM30F70U_(U).book Page 292 Monday, January 19, 2015 9:34 AM

294
GS450h_OM_OM30F70U_(U)
4-5. Using the driving support systems
■The pre-collision system is operational when
The PCS OFF switch is not pressed and the following conditions are met:
●Pre-collision warning:
• Vehicle speed is greater than about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-ning ahead of you is greater than about 10 mph (15 km/h).
●Pre-collision seat belts (operating conditions A):
• Vehicle speed is greater than about 19 mph (30 km/h).
• The system detects sudden braking or skidding.
• The front occupants are wearing a seat belt.
●Pre-collision seat belts (operating conditions B):
• Vehicle speed is greater than about 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-ning ahead of you is greater than about 19 mph (30 km/h).
• The front occupants are wearing a seat belt.
●Pre-collision brake assist:
• Vehicle speed is greater than about 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle run- ning ahead of you is greater than about 19 mph (30 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• Vehicle speed is greater than about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle run- ning ahead of you is greater than about 10 mph (15 km/h).
●Suspension control:
• Vehicle speed is greater than about 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-ning ahead of you is greater than about 19 mph (30 km/h).
●Pre-collision alert braking:
• The system determines that the driver is not facing forward, or that the driver’seyes are closed.
• Vehicle speed is greater than about 25 mph (40 km/h).
• The speed at which your vehicle is approaching the vehicle running ahead of you is greater than about 25 mph (40 km/h).
• The steering is not being turned.
GS450h_OM_OM30F70U_(U).book Page 294 Monday, January 19, 2015 9:34 AM