2018 Lexus GS450h Owner's Manual / LEXUS 2018 GS450H OWNER'S MANUAL (OM30G62U)

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2254-5. Using the driving support systems
4
Driving
WARNING
■Pre-collision braking
●When the pre-collision braking function is operating, a large amount of braking force
will be applied.
●If the vehicle is stopped by the operation of the pre-collision braking function, the pre-
collision braking function operation will be canceled after approximately 2 seconds.
Depress the brake pedal as necessary.
●The pre-collision braking fu nction may not operate if certain operations are per-
formed by the driver. If the accelerator pedal is being depressed strongly or the steer-
ing wheel is being turned, the system may de termine that the driver is taking evasive
action and possibly prevent the pre-coll ision braking function from operating.
●In some situations, while the pre-collision braking function is operating, operation of
the function may be canceled if the accele rator pedal is depressed strongly or the
steering wheel is turned and the system de termines that the driver is taking evasive
action.
●If the brake pedal is being depressed, the sy stem may determine that the driver is tak-
ing evasive action and possibly delay the op eration timing of the pre-collision braking
function.
■When to disable the pre-collision system
In the following situations, di sable the system, as it may not operate properly, possibly
leading to an accident resultin g in death or serious injury:
●When the vehicle is being towed
●When your vehicle is towing another vehicle
●When transporting the vehicle via truck, bo at, train or similar means of transportation
●When the vehicle is raised on a lift with the hybrid system on and the tires are allowed
to rotate freely
●When inspecting the vehicle using a drum tester such as a chassis dynamometer or
speedometer tester, or when using an on vehicle wheel balancer
●When a strong impact is applied to the fron t bumper or front grille, due to an accident
or other reasons
●If the vehicle cannot be driven in a stable manner, such as when the vehicle has been
in an accident or is malfunctioning
●When the vehicle is driven in a sporty manner or off-road
●When the tires are not properly inflated
●When the tires are very worn
●When tires of a size other than specified are installed
●When tire chains are installed
●When a compact spare tire or an emergency tire puncture repair kit is used
●If equipment (snow plow, etc.) that may obstruct the radar sensor or camera sensor is
temporarily installed to the vehicle

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4-5. Using the driving support systems
■Enabling/disabling the pre-collision system
The pre-collision system can be enabled/disabled on (→P. 95) of
the multi-information display.
The system is automatically enabled each time the power switch is turned to ON
mode.
If the system is disabled, the PCS
warning light will turn on and a mes-
sage will be displayed on the multi-
information display.
■Changing the pre-collision warning timing
The pre-collision warning timing can be changed on ( →P. 95) of the
multi-information display.
The operation timing settin g is retained when the power switch is turned off.
Far
The warning will begin to operate
earlier than with the default timing.
Middle
This is the default setting.
Near
The warning will begin to operate
later than with the default timing.
Changing settings of the pre-collision system
1
2
3

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2274-5. Using the driving support systems
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Driving
■Operational conditions
The pre-collision system is enabled and the system determines that the possibility of a
frontal collision with a vehicle or pedestrian is high.
Each function is operationa l at the following speeds:
●Pre-collision warning:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10
and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 7 mph (10 km/h) or more.
●Pre-collision brake assist:
• Vehicle speed is between approximately 20 and 110 mph (30 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 20 and 50 mph
[30 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 20 mph (30 km/h) or more.
●Pre-collision braking:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (Fordetecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10
and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 7 mph (10 km/h) or more.
The system may not operate in the following situations:
●If a 12-volt battery terminal has been disconnected and reconnected and then the vehi-
cle has not been driven for a certain amount of time
●If the shift lever is in R
●If VSC is disabled (only the pre-collis ion warning function will be operational)

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4-5. Using the driving support systems
■Pedestrian detection function
■Cancelation of the pre-collision braking
If either of the following occur while the pre-collision braking function is operating, it will
be canceled:
●The accelerator pedal is depressed strongly.
●The steering wheel is turned sharply or abruptly.
■Conditions under which the system may operate even if th ere is no possibility of a colli-
sion
●In some situations such as the following, th e system may determine that there is a possi-
bility of a frontal collision and operate.
• When passing a vehicle or pedestrian
• When changing lanes while overtaking a preceding vehicle
• When overtaking a preceding vehicle that is changing lanes
The pre-collision system detects pedestrians
based on the size, prof
ile, and motion of a
detected object. However, a pedestrian may not
be detected depending on the surrounding
brightness and the motion, posture, and angle of
the detected object, preventing the system from
operating properly. ( →P. 232)
• When overtaking a preceding vehicle that is making a left/right turn
• When passing a vehicle in an oncoming lane that is stopped to make a right/left turn

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2294-5. Using the driving support systems
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Driving
• When rapidly closing on a vehicle ahead
• If the front of the vehicle is raised or lowered, such as when the road surface isuneven or undulating
• When approaching objects on the roadside, such as guardrails, utility poles, trees, or walls
• When driving on a narrow path surrounded by a structure, such as in a tunnel or on
an iron bridge
• When there is a metal object (manhole cover, steel plate, etc.), steps, or a protrusion
on the road surface or roadside
• When driving on a road where relative
location to vehicle ahead in an adjacent
lane may change, such as on a winding
road
• When there is a vehicle, pedestrian, or object by the roadside at the entrance of a
curve
• When a crossing pedestrian approaches very close to the vehicle
• When passing through a place with a low structure above the road (low ceiling, traffic
sign, etc.)

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4-5. Using the driving support systems
• When rapidly closing on an electric toll ga te barrier, parking area barrier, or other
barrier that opens and closes
• When using an automatic car wash
• When the vehicle is hit by water, sn ow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When there are patterns or paint on the road or a wall that may be mistaken for a
vehicle or pedestrian
• When driving near an object that reflects radio waves, such as a large truck or
guardrail
• When driving near a TV tower, broadcasting station, electric power plant, or other location where strong radio waves or electrical noise may be present
• When passing under an object (billboard,
etc.) at the top of an uphill road
• When driving through or under objects that may contact the vehicle, such as thick
grass, tree branches, or a banner

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2314-5. Using the driving support systems
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Driving
■Situations in which the system may not operate properly
●In some situations such as the following, a vehicle may not be detected by the radar
sensor and camera sensor, preventing the system from operating properly:
• If an oncoming vehicle is approaching your vehicle
• If a vehicle ahead is a motorcycle or bicycle
• When approaching the side or front of a vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shap ed, such as a tractor or side car
• If the sun or other light is shin ing directly on a vehicle ahead
• If a vehicle cuts in front of your ve hicle or emerges from beside a vehicle
• If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, accelera-
tion or deceleration)
• When suddenly cutting behind a preceding vehicle
• When driving in inclement we ather such as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, sn ow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel
• When a very bright light, such as the sun or the headlights of on coming traffic, shines
directly into the camera sensor
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel
• If a preceding vehicle has a low rear end,
such as a low bed trailer
• If a vehicle ahead has extremely high ground clearance
• When a vehicle ahead is not directly in front of your vehicle

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4-5. Using the driving support systems
• After the hybrid system has started the vehicle has not been driven for a certain
amount of time
• While making a left/right turn and for a few seconds after making a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the wheels are misaligned
• If a wiper blade is blocking the camera sensor
• The vehicle is wobbling.
• The vehicle is being driven at extremely high speeds.
• When driving on a hill
• If the radar sensor or ca mera sensor is misaligned
●In some situations such as the following, sufficient braking forc e may not be obtained,
preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when the brake parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively worn,
improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery surface
●Some pedestrians such as the following may not be detected by the radar sensor and
camera sensor, preventing the system from operating properly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approximately
6.5 ft. (2 m)
• Pedestrians wearing oversized clothing (a ra in coat, long skirt, etc.), making their sil-
houette obscure
• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part
of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller , wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to be nearly the same color or brightness as
their surroundings
• Pedestrians near walls, fences , guardrails, or large objects
• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly
• Pedestrians running out from be hind a vehicle or a large object
• Pedestrians who are extremely close to the side of the vehicle (outside rear view mirror, etc.)
• If the front of the vehicle is raised or low-
ered