brakes Lexus GS350 2014 Do-it-yourself maintenance /

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GS350_OM_OM30D41U_(U)
4-5. Using the driving support systems
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in
front of you.
As the sensor may not be able to correc tly detect these types of vehicles, the
approach warning ( P. 221) will not be activated, and a fatal or serious accident
may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane
■Conditions under which the vehicle-to-veh icle distance control may not function
correctly
Apply the brakes as necessary in the following conditions as the radar sensor may
not be able to correctly detect vehicles ahead, and a fatal or serious accident may
result:
●When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor
●When your vehicle is pointing upwards (caused by a heavy load in the trunk etc.)
●When the road curves or when the lanes are narrow
●When steering wheel operation or your position in the lane is unstable
●When the vehicle ahead of you decelerates suddenly

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GS350_OM_OM30D41U_(U)
4-5. Using the driving support systems
■Intuitive parking assist display
When an obstacle is detected while the rear view monitor system, is in use, the warn-
ing indicator will appear in the top right of the screen even if the display setting has
been set to off.
■Sensor detection information
●The sensor’s detection areas are limited to the areas around the vehicle’s bumpers.
●Certain vehicle conditions and the surrounding environment may affect the ability
of the sensor to correctly detect obstacles. Particular instances where this may
occur are listed below.
• There is dirt, snow or ice on the sensor. (Wiping the sensors will resolve this problem.)
• The sensor is frozen. (Thawing the area will resolve this problem.) In especially cold weather, if a sensor is frozen the screen may show an abnor-
mal display, or obstacle s may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines, air brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather.
• The area directly under th e bumpers is not detected.
• If obstacles draw too close to the sensor.
• A non-genuine Lexus suspension (low ered suspension etc.) is installed.
• People may not be detected if they are wearing certain types of clothing.
In addition to the examples above, there are instances in which, because of their
shape, signs and other objects may be judged by the se nsor to be closer than they
are.

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GS350_OM_OM30D41U_(U)4-5. Using the driving support systems
4
Driving
Driving assist systems
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lo ck when the brakes are applied suddenly, or if
the brakes are applied while dri ving on a slippery road surface
◆Brake assist
Generates an increased level of br aking force after the brake pedal is
depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning
on slippery road surfaces
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road
surfaces by controllin g steering performance.
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spin-
ning when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
P. 2 7 7
◆VGRS (Variable Gear Ratio Steering) (if equipped)
Adjusts the front wheel turning angl e in accordance with the vehicle
speed and steering wheel movement
To help enhance driving safety an d performance, the following systems
operate automatically in response to various driving situations. Be
aware, however, that these systems are supplementary and should not
be relied upon too heavily when operating the vehicle.

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4-5. Using the driving support systems
◆DRS (Dynamic Rear Steering) (if equipped)
Contributes to the turning characteristics and responsiveness of the
vehicle by slightly adjusting the rear wheel angle of the vehicle in accor-
dance with steering wheel movement
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆AVS (Adaptive Variable Suspension system) (if equipped)
By independently controlling the damping force of the shock absorbers
for each of the 4 wheel s according to the road and driving conditions,
this system helps riding comfort with superior steering stability, and
helps good vehicle posture
When SPORT S+ mode is selected by the driving mode select switch,
the damping force is suitable for sporty driving ( P. 266)
◆LDH (Lexus Dynamic Handlin g system) (if equipped)
Provides independent control of the VGRS, DRS and EPS. Contributes
to turning characteristics at low speeds, responsiveness at medium
speeds and safety at high speeds by controlling the steering angle of
the front and rear wheels in accorda nce with the steering wheel opera-
tion and vehicle speed
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the AB S, brake assist, TRAC, VSC, hill-
start assist control, EPS, VGRS (if equipped) and DRS (if equipped)
systems
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes, engine output, steering assist, and
steering ratio and rear wheel angle
◆PCS (Pre-Collision System) (if equipped)
 P. 279

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GS350_OM_OM30D41U_(U)4-5. Using the driving support systems
4
Driving
Hill-start assist control
To engage hill-start assist control,
further depress the brake pedal
when the vehicle is stopped com-
pletely.
A buzzer will sound once to indicate
the system is activated. The slip indica-
tor will also start flashing.
■Hill-start assist control operating conditions
●The system operates in the following situations:
• The shift lever is in a position other than P.
• The parking brake is not applied.
• The accelerator peda l is not depressed.
●Hill-start assist control cannot be operated while the slip indicator light is illumi-
nated.
■Hill-start assist control
●While hill-start assist control is operating, the brakes remain automatically applied
after the driver releases the brake pedal. The stop lights and the high mounted
stoplight turn on.
●Hill-start assist control operates for about 2 seconds after the brake pedal is
released.
●If the slip indicator does not flash and the buzzer does not sound when the brake
pedal is further depressed, slightly reduce the pressure on the brake pedal (do not
allow the vehicle to roll backward) and then firmly depress it again. If the system still
does not operate, check that the operating conditions explained above have been
met.
Assists with starting off and temporarily maintains braking power even
if the foot is removed from the brake pedal when starting off on an
incline or a slippery slope.

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GS350_OM_OM30D41U_(U)4-5. Using the driving support systems
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Driving
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 dr iver makes an emergency braking or
loses control of the vehicle. ( P. 32)
◆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 poss ibility of a frontal collision, the system warns
the driver using a warning light, war ning 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 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 ca n be turned on and off as necessary by oper-
ating the switch. ( P. 2 8 1 )

GS350_OM_OM30D41U_(U)
2834-5. Using the driving support systems
4
Driving
■Conditions that may trigger the system even if there is no danger of a collision
●When there is an object by the roadside at the entrance to a curve
●When passing an oncoming vehicle on a curve
●When driving over a narrow iron bridge
●When there is a metal object on the road surface
●When driving on an uneven road surface
●When passing an oncoming vehicle on a left-turn
●When your vehicle rapidly closes on the vehicle in front
●When a grade separation/interchange, sign , billboard, or other structure appears
to be directly in the vehicle’s line of travel
●When climbing a steep hill causes an overhead billboard or other metallic structure
to appear directly in the vehicle’s line of travel
When the system is activated in the situations described above, there is also a possi-
bility that the seat belts will retract quickly and the brakes will be applied with a force
greater than normal. When the seat belt is locked in the retracted position, stop the
vehicle in a safe place, release the seat belt and refasten it.
■Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may also be
occasions when the sensor cannot detect pedestrians, animals, bicycles, motorcy-
cles, trees, or snowdrifts.
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp bends or uneven surfaces
●If a vehicle suddenly moves in front of your vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heavy rain, fog, snow or sand storms
●When your vehicle is skidding
●When your vehicle is steeply inclined
●When the radar sensor moves off position due to its surrounding area being sub-
jected to a strong impact

GS350_OM_OM30D41U_(U)
3054-6. Driving tips
4
Driving
Perform the following according to the driving conditions:
●Do not try to forcibly open a window or move a wiper that is frozen.
Pour warm water over the frozen area to melt the ice. Wipe away the
water immediately to prevent it from freezing.
●To ensure proper operation of the climate control system fan, remove
any snow that has accumulated on the air inlet vents in front of the wind-
shield.
●Check for and remove any excess ice or snow that may have accumu-
lated on the exterior lights, vehicle’s roof, chassis, around the tires or on
the brakes.
●Remove any snow or mud from the bo ttom of your shoes before getting
in the vehicle.
Accelerate the vehicle slowly, keep a safe distance between you and the
vehicle ahead, and drive at a reduced speed suitable to road conditions.
Park the vehicle and move the shift lever to P without setting the parking
brake. The parking brake may freeze up, preventing it from being
released. If necessary, block the wheels to prevent inadvertent sliding or
creeping.
Before driving the vehicle
When driving the vehicle
When parking the vehicle

GS350_OM_OM30D41U_(U)
6196-2. Maintenance
6
Maintenance and care
Ve h i c l e i n t e r i o r
ItemsCheck points
Accelerator pedal
• The accelerator pedal should movesmoothly (without uneven pedal
effort or catching).
Automatic transmission “Park” mecha-
nism• When parked on a slope and the shiftlever is in P, is the vehicle securely
stopped?
Brake pedal
• Does the brake pedal movesmoothly?
• Does the brake pedal have appropri- ate clearance from the floor? ( P. 7 74 )
• Does the brake pedal have the cor- rect amount of free play? ( P. 7 74 )
Brakes
• The vehicle should not pull to one
side when the brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should not get too close to the floor when the brakes are
applied.

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7
When trouble arises
7-1. Essential information
If your vehicle has to be stopped in an emergency
Steadily step on the brake pedal with both feet and firmly depress it.
Do not pump the brake pedal repeatedly as this will increase the effort required to
slow the vehicle.
Shift the shift lever to N.
If the shift lever is shifted to N
After slowing down, stop the vehicle in a safe place by the road.
Stop the engine.
If the shift lever cannot be shifted to N
Keep depressing the brake pedal wi th both feet to reduce vehicle
speed as much as possible.
To stop the engine, press and
hold the engine switch for 2 con-
secutive seconds or more, or
press it briefly 3 times or more in
succession.
Stop the vehicle in a safe place by the road.
Only in an emergency, such as if it becomes impossible to stop the vehi-
cle in the normal way, stop the vehicle using the following procedure:
1
2
3
4
3
Press and hold for 2 seconds or more
or press briefly 3 times or more
4
CAUTION
■If the engine has to be turned off while driving
Power assist for the brakes and steering wheel will be lost, making the brake pedal
harder to depress and the steering wheel heavier to turn. Decelerate as much as
possible before turning off the engine.
5