brakes Lexus GS300h 2017 Owner's Manual

201
4-1. Before driving
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■When starting off on a uphill
The hill-start assist control is available. ( P. 325)
■For fuel-efficient driving
Keep in mind that hybrid vehicles are similar to conventional vehicles, and it is necessary
to refrain from activities such as sudden acceleration, etc. Refer to “Hybrid vehicle driv-
ing tips”. ( P. 331)
■Driving in the rain
●Drive carefully when it is ra ining, because visibility will be reduced, the windows may
become fogged-up, and the road will be slippery.
●Drive carefully when it starts to rain, because the road surface will be especially slip-
pery.
●Refrain from high speeds when driving on an expressway in the rain, because there may
be a layer of water between the tires and the road surface, preventing the steering and
brakes from operating properly.
■Restraining hybrid system outp ut (Brake Override System)
●When the accelerator and brake pedals are depressed at the same time, the hybrid sys-
tem output may be restrained.
●A warning message is displayed on the mult i-information display while the system is
operating. ( P. 485)
■Restraining sudden start (Drive-Start Control)
●When the following unusual operation is pe rformed, the hybrid system output may be
restrained.

2044-1. Before driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When driving on slippery road surfaces
●Sudden braking, acceleration and steering may cause tire slippage and reduce your
ability to control the vehicle.
●Sudden acceleration, engine braking due to shifting, or changes in engine speed
could cause the vehicle to skid, resulting in an accident.
●After driving through a puddle, lightly depress the brake pedal to make sure that the
brakes are functioning properly. Wet brake pads may prevent the brakes from func-
tioning properly. If the brakes on only one side are wet and not functioning properly,
steering control may be affected.
■When shifting the shift lever
●Do not let the vehicle roll backward while the shift lever is in a driving position, or roll
forward while the shift lever is in R.
Doing so may result in an accident or damage to the vehicle.
●Do not shift the shift lever to P while the vehicle is moving.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Do not shift the shift lever to R while the vehicle is moving forward.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Do not shift the shift lever to a driving position while the vehicle is moving backward.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Shifting the shift lever to N while the vehicle is moving will disengage the hybrid sys-
tem. Engine braking is not available with the hybrid system disengaged.
●Be careful not to shift the shift lever with the accelerator pedal depressed. Shifting the
shift lever to any position other than P or N may lead to unexpected rapid accelera-
tion of the vehicle that may cause an accident and result in death or s erious injury.
■If you hear a squealing or scraping noise (brake pad wear indicators)
Have the brake pads checked and replaced by any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer as soon as possible.
Rotor damage may result if the pads are not replaced when needed.
Front and rear*
brakes: Moderate levels of brake pad and disc wear allow enhanced
braking power. As a result, the discs may wear more quickly than conventional brake
discs. Therefore, when replacing the brake pads, Lexus recommends that you also
have the thickness of the discs measured.
It is dangerous to drive the vehicle when th e wear limits of the brake pads and/or those
of the brake discs are exceeded.
* : Except for Reunion, Canary Islands, Russi a, Ukraine, Israel, Turkey, Kazakhstan,
Georgia

2064-1. Before driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the shift lever or
depress the accelerator pedal, this could cause an accident or fire due to hybrid system
overheating. Additionally, if the vehicle is parked in a poorly ventilated area, exhaust
gases may collect and enter the vehicle, lead ing to death or a serious health hazard.
■When braking
●When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this may cause one side of
the vehicle to brake differently than the other side. Also, the parking brake may not
securely hold the vehicle.
●If the electronically controlled brake system does not operate, do not follow other
vehicles closely and avoid hills or sharp turns that require braking.
In this case, braking is still possible, but the brake pedal should be depressed more
firmly than usual. Also, the braking distance will increase. Have your brakes fixed
immediately.
●The brake system consists of 2 or more indi vidual hydraulic systems; if one of the sys-
tems fails, the other(s) will still operate. In this case, the brake pedal should be
depressed more firmly than usual and the braking distance will increase. Have your
brakes fixed immediately.
■If the vehicle becomes stuck
Do not spin the wheels excessively when any of the tires is up in the air, or the vehicle is
stuck in sand, mud, etc. This may damage the driveline components or propel the vehi-
cle forward or backward, causing an accident.

2144-1. Before driving
GS450h_300h_OM_OM30F92E_(EE) Your vehicle will handle differently when towing a trailer
. In order to avoid acci-
dent, death or serious injury, keep the following in mind when towing:
■Checking connections between trailer and lights
Stop the vehicle and check the operation of the connection between the
trailer and lights after driving for a brief period as well as before starting off.
■Practicing driving with a coupled trailer ●Get the feel for turning, stopping an d reversing with the trailer coupled by
practicing in an area with no or light traffic.
● When reversing with a coupled trailer, hold the section of the steering
wheel nearest to you and rotate clockwise to turn the trailer left or counter-
clockwise to turn it right. Always rotate a little at a time to prevent steerin g
error. Have someone guide you when reversing to lessen the risk of an
accident.
■Increasing vehicle-to-vehicle distance
At a speed of 10 km/h (6 mph), the distance to the vehicle runni ng ahead of
you should be equivalent to or greater than the combined length of your v ehi-
cle and trailer. Avoid sudden braking that may cause skidding. Otherwise, the
vehicle may spin out of control. This is especially true when driving on wet or
slippery road surfaces.
■Sudden acceleration/steering input/cornering
Executing sharp turns when towing may result in the trailer colliding with your
vehicle. Decelerate well in advance when approaching turns and take them
slowly and carefully to avoid sudden braking.
■Important points regarding turning
The wheels of the trailer will travel closer to the inside of the curve than the
wheels of the vehicle. To make allowance for this, take the turns wider than you
would normally do.
■Important points regarding stability
Vehicle movement resulting from uneven road surfaces and strong cross-
winds will affect handling. The vehicle may also be rocked by passing buses or
large trucks. Frequently check behind when moving alongside such vehicles.
As soon as such vehicle movement occurs, immediately start to decelerate
smoothly by slowly applying the brakes. Always steer the vehicle straight
ahead while braking.
Guidance

235
4
4-2. Driving procedures
Driving
GS450h_300h_OM_OM30F92E_(EE)
Brake Hold
Turns the brake hold system onThe brake hold standby indicator
(green) comes on. While the system is
holding the brake, the brake hold oper-
ated indicator (yellow) comes on.
■Brake hold system operating conditions
The brake hold system cannot be turn ed on in the following conditions:
●The driver’s door is not closed.
●The driver is not wearing the seat belt.
●“EPB Activation Stopped Incompletely” or “Electronic Parking Brake Malfunction Visit
Your Dealer” is displayed on the multi-information display.
If any of the conditions above are detected when the brake hold system is enabled, the
system will turn off and the brake hold standby indicator light will go off. In addition, if any
of the conditions are detected while the sy stem is holding the brake, a warning buzzer
will sound and a message will be shown on th e multi-information display. The parking
brake will then be set automatically.
■Brake hold function
●If the brake pedal is left released for a pe riod of about 3 minutes after the system has
started holding the brake, th e parking brake will be set automatically. In this case, a
warning buzzer sounds and a message is shown on the multi-information display.
●To turn the system off while the system is holding the brake, firmly depress the brake
pedal and press the button again.
●The brake hold function may not hold the vehicle when the vehicle is on a steep incline.
In this situation, it may be necessary for the driver to apply the brakes. A warning
buzzer will sound and the multi-information disp lay will inform the driver of this situa-
tion. ( P. 466)
The brake hold system keeps the brake appl ied when the shift lever is in D, S or
N with the system on and the brake peda l has been depressed to stop the vehi-
cle. The system releases the brake when the accelerator pedal is depressed
with the shift lever in D or S to allow smooth start off.

2364-2. Driving procedures
GS450h_300h_OM_OM30F92E_(EE)
■When the parking brake is set automatically while the system is holding the brakes
The parking brake will not be released auto matically. Perform one of the following proce-
dures to release the parking brake and conf irm that the parking brake indicator light
turns off. ( P. 232)
●With the brake pedal depressed, operate the parking brake switch.
●Fasten your seat belt, check that the shift leve r is in either D or R and slowly depress the
accelerator pedal.
■Warning message and buzzers
Warning messages and buzzers are used to indicate a system malfunction or to inform
the driver of the need for caution. ( P. 466)
WARNING
■When the vehicle is on a steep incline
When using the brake hold system on a steep incline exercise caution. The brake hold
function may not hold the vehicle in such a situation.
■When stopped on a slippery road
The system cannot stop the vehicle when the gripping ability of the tires has been
exceeded. Do not use the system when stopped on a slippery road.
NOTICE
■When parking the vehicle
The brake hold system is not designed fo r use when parking the vehicle for a long
period of time. Turning the power switch o ff while the system is holding the brake may
release the brake, which would cause the vehicle to move. When operating the power
switch, depress the brake pedal, set the pa rking brake and shift the shift lever to P.

2704-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
PCS (Pre-Crash Safety system) 
◆Pre-crash warning
When the system determines that
the possibility of a frontal collision is
high, a buzzer will sound and a warn-
ing message will be displayed on the
multi-information display to urge the
driver to take evasive action.
◆Pre-crash brake assist
When the system determines that the possibility of a frontal collision is high,
the system applies greater braking force in relation to how strongly the brake
pedal is depressed.
: If equipped
The pre-crash safety system uses a radar sensor and camera sensor to detect
vehicles and pedestrians *1
in front of your vehicle. When the system deter-
mines that the possibility of a frontal collision with a vehicle or pedestrian is
high, a warning operates to urge the dr iver to take evasive action and the
potential brake pressure is increased to help the driver avoid the collision. If
the system determines that the possibility of a frontal collision with a vehicle o r
pedestrian is extremely high, the brakes are automatically applied *2
to help
avoid the collision or help reduce the impact of the collision.
The pre-crash safety system can be disabled/enabled and the warning timing
can be changed. ( P. 273)
* 1
: Depending on the region in which the vehicle was sold, the pedestrian detection
function may not be available. Contact any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer for details.
* 2
: Depending on the region in which the vehicle was sold, the pre-crash braking func-
tion (automatic braking function) may not be available. Contact any authorized
Lexus retailer or Lexus authorized repair er, or any reliable repairer for details.

271
4-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
◆Pre-crash braking *3
When the system determines that the possibility of a frontal collision is high,
the system warns the driver. If the system determines that the possibility of a
frontal collision is extremely high, the brakes are automatically applied to h elp
avoid the collision or reduce the collision speed.
* 3
: Depending on the region in which the vehicle was sold, the pre-crash braking function
may not be available.
◆Suspension control (if equipped)
When the system determines that the possibility of a frontal collision is high,
the Adaptive Variable Suspension System ( P. 325) will control the damping
force of the shock absorbers to help maintain an appropriate vehicle posture.
◆Steering control (if equipped)
When the system determines that the possibility of a frontal collision is hi gh
and the driver is operating the steering wheel, the LDH system ( P. 325) will
control the turning angle of the front and rear wheels and effort necessary to
turn the steering wheel to help enhance steering responsiveness.
WARNING
■Limitations of the pre-crash safety system
●The driver is solely responsible for safe driving. Always drive safely, taking care to
observe your surroundings.
Do not use the pre-crash safety system instead of normal braking operations under
any circumstances. This system will not pr event collisions or lessen collision damage
or injury in every situation. Do not overly re ly on this system. Failure to do so may lead
to an accident, resulting in death or serious injury.
●Although this system is designed to help avoid a collision or help reduce the impact of
the collision, its effectiveness may change according to various conditions, therefore
the system may not always be able to achieve the same level of performance.
Read the following conditions carefully. Do not overly rely on this system and always
drive carefully.

299
4-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE) This mode employs a radar sensor to detect the presence of vehicles up to
approximately 100 m (328 ft.) ahead, determines the current vehicle-to-vehicle
following distance, and operates to maintain a suitable following distance from
the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long downhill
slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle dis-
tance can also be set by operating the vehicle-to-vehicle distance button.
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 deceler-
ates 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 wa rning warns you when the system cannot
decelerate sufficiently to prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your ve hicle will also stop (vehicle is stopped by
system control). After the vehicle ahead starts off, pushing the cruise control lever up
or depressing the accelerator pedal will resume follow-up cruising.
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 reached. The system then returns to con-
stant speed cruising.
Driving in vehicl e-to-vehicle distance control mode
1
2
3

309
4-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE) To change the set speed, operate the lever until the desired set speed is obtained.
Increases the speed
Decreases the speed
Fine adjustment: Momentarily move the
lever in the desired direction.
Large adjustment: Hold the lever in the
desired direction.
The set speed will be increased or decreased as follows:
Fine adjustment: By approximately 1.6 km/h (1 mph) each time the lever is operated.
Large adjustment: The set spee d can be increased or decreased continually until the
lever is released.
Pulling the lever toward you cancels
the constant speed control.
The speed setting is also canceled when
the brakes are applied.
Pushing the lever up resumes the
constant speed control.
Resuming is available when the vehicle
speed is more than approximately
40 km/h (25 mph).
■Cruise control can be set when
●The shift lever is in D or range 4 or higher of S has been selected.
●Range 4 or higher of D has been selected by using the paddle shift.
●Vehicle speed is above approximately 40 km/h (25 mph).
■Accelerating after setting the vehicle speed
●The vehicle can be accelerated normally. After acceleration, the set speed resumes.
●Even without canceling the cruise control, the set speed can be increased by first accel-
erating the vehicle to the desired speed and then pushing the lever down to set the new
speed.
Adjusting the set speed
1
2
Canceling and resuming the constant speed control
1
2