brake Lexus GS F 2015 s Workshop Manual

3514-5. Using the driving support systems
4
Driving
GS350_200t_GS F_OM_OM30E87E_(EE)
■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 16 km/h (10 mph) below the set vehi-
cle speed.
●Actual vehicle speed falls below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
●Pre-crash braking is activated.
If constant speed control mode is automatically canceled for any other reason, there may
be a malfunction in the system. Contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
■Warning messages and buzzers for dynamic radar cruise control
Warning messages and buzzers are used to in dicate a system malfunction or to inform
the driver of the need for caution while driv ing. If a warning message is shown on the
multi-information display, read the message and follow the instructions. ( →P. 5 1 8 )
■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 insufficient 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. 336) 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

3524-5. Using the driving support systems
GS350_200t_GS F_OM_OM30E87E_(EE)
■Conditions under which the vehicle-to-vehicle distance control mode may not function
correctly
In the case of the following conditions, operate the brake pedal (or accelerator pedal,
depending on the situation) as necessary.
As the sensor may not be able to correctly detect vehicles ahead, the system may not
operate properly.
●When the vehicle ahead of you decelerates suddenly
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.)
●Preceding vehicle has an extremely high
ground clearance
●When the road curves or when the lanes are
narrow
●When steering wheel operation or your posi-
tion in the lane is unstable

3544-5. Using the driving support systems
GS350_200t_GS F_OM_OM30E87E_(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 speed can be incr eased 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).
Adjusting the set speed
1
2
Canceling and resuming th e constant speed control
1
2

3744-5. Using the driving support systems
GS350_200t_GS F_OM_OM30E87E_(EE)
Driving assist systems
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if the
brakes are applied while driving on a slippery road surface
◆Brake assist
Generates an increased level of braking 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
◆VSC+ (Vehicle Stability Control+)
Provides cooperative control of the ABS, TRC, VSC and EPS. Helps to main-
tain directional stability when swerving on slippery road surfaces by control-
ling steering performance.
◆TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
To help enhance driving safety and performance, the following systems oper-
ate 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.

3754-5. Using the driving support systems
4
Driving
GS350_200t_GS F_OM_OM30E87E_(EE)
◆Hill-start assist control
Helps to prevent the vehicle from rolling backward when starting on an
incline.
◆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 wheels 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. 3 5 7 )
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRC, VSC, hill-start
assist control and EPS systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes, engine output, steering assist, and steering ratio
◆Emergency brake signal
When the brakes are applied suddenly, the stop lights automatically flash to
alert the vehicle behind
The slip indicator light will flash while
the TRC/VSC systems are operating.
When the TRC/VSC systems are operating

3774-5. Using the driving support systems
4
Driving
GS350_200t_GS F_OM_OM30E87E_(EE)
■Turning off both TRC and VSC systems
XGS350/GS200t
To turn the TRC and VSC systems off, pres s and hold for more than 3 seconds while
the vehicle is stopped.
The VSC OFF indicator light will come on and the “Traction Control Turned Off” will be
shown on the multi-information display.
*
Press again to turn the systems back on.
XGS F
To turn the TRC and VSC systems off, press and hold for more than 3 seconds.
The “TRC OFF” indicator light and the VSC OFF indicator light will come on.
*
Press again to turn the systems back on.
*: On vehicles with PCS (Pre-Crash Safety system), pre-crash brake assist and pre-
crash braking will also be disabled. The PC S (Pre-Crash Safety system) warning light
will come on and a message will be displa yed on the multi-information display.
( → P. 5 1 8 )
■Expert mode (GS F)
When expert mode is selected, it is possible to drive in a more sporty manner than other
drive modes. Expert mode disables the TRC and VSC systems but the engine and
brakes may be controlled depending on the vehicle behavior.
■When the message is displayed on the mult i-information display showing that TRC has
been disabled even if has not been pressed (GS350/GS200t)
TRC and hill-start assist control cannot be operated. Contact any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional. To select expert mode, press when in
SPORT S+ mode.
The “EXPERT” indicator will come on together
with the TRC OFF and VSC OFF indicators.
To cancel expert mode, press or use the
driving mode select swit ch to select a driving
mode other than SPORT S+ mode.

3784-5. Using the driving support systems
GS350_200t_GS F_OM_OM30E87E_(EE)
■When the “TRC OFF” indicator light comes on even if has not been pressed (GS F)
TRC and hill-start assist control cannot be operated. Contact any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
■Sounds and vibrations caused by the ABS, brake assist, VSC, Hill-start assist control
and TRC systems
●A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the engine is started or just after the vehicle begins to
move. This sound does not indicate that a ma lfunction has occurred in any of these sys-
tems.
●Any of the following conditions may occu r when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slig htly after the ABS is activated.
• The brake pedal may move down s lightly after the ABS is activated.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled
in the following situations:
●When the engine switch is turned off
●If only the TRC system is turned off, the TRC will turn on when vehicle speed increases
If both TRC and VSC systems are turned off, automatic re-enabling will not occur when
vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result. Should this occur, refrain from excessive steering input
or stop the vehicle and turn the engine off. The EPS system should return to normal
within 10 minutes.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate;
●The shift lever is in a position other than N or P (when starting off forward/backward on
an upward incline).
●The vehicle is stopped.
●The accelerator pedal is not depressed.
●The parking brake is not engaged.

3794-5. Using the driving support systems
4
Driving
GS350_200t_GS F_OM_OM30E87E_(EE)
■Automatic system cancelation of hill-start assist control
The hill-start assist control will be canceled in any of the following situations;
●The shift lever is shifted to N or P.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse after the brake pedal is released.
■Operating conditions of emergency brake signal
When the following three conditions are me t, the emergency brake signal will operate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The brake pedal is depressed in a manner that cause the system to judge from the vehi-
cle deceleration that this is a sudden braking operation.
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn off in any of the following situations:
●The emergency flashers are turned on.
●The brake pedal is released.
●The system judges from the vehicle deceleration that is not a sudden braking operation.

3804-5. Using the driving support systems
GS350_200t_GS F_OM_OM30E87E_(EE)
WA R N I N G
■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 conditions
The ABS is not designed to shorten the vehi cle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:
●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
■TRC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the TRC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■Hill-start assist control does not operate effectively when
●Do not overly rely on the hill-start assist control. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle
stationary for an extended period of time. Do not attempt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident.
■When the VSC is activated
The slip indicator light flashes. Always dr ive carefully. Reckless driving may cause an
accident. Exercise particular care when the indicator light flashes.
■When the TRC/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 vehicle stability and driving force, do not turn the TRC/
VSC systems off unless necessary.

3834-6. Driving tips
4
Driving
GS350_200t_GS F_OM_OM30E87E_(EE)
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 imme-
diately 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 windshield.
●Check for and remove any excess ice or snow that may have accumulated on
the exterior lights, vehicle’s roof, chassis, around the tires or on the brakes.
●Remove any snow or mud from the bottom 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 leve r 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.
XVehicles with front and rear tires of the same size
Use the correct tire chain size when mounting the tire chains.
Chain size is regulated for each tire size.
Side chain
(3 mm [0.12 in.] in diameter)
Cross chain
(4 mm [0.16 in.] in diameter)
XVehicles with front and rear tires of differing sizes
Tire chains cannot be mounted.
Snow tires should be used instead.
Before driving the vehicle
When driving the vehicle
When parking the vehicle
Selecting tire chains (GS350/GS200t)
1
2