2015 Lexus GS350 Owner's Manual

GS350_OM_OM30F69U_(U)
2474-5. Using the driving support systems
4
Driving
■Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air
conditioning system to enhance fuel efficiency (→P. 299). To improve air condition-
ing performance, adjust the fan speed or turn off Eco drive mode.
■Automatic operation of the seat heater during Eco drive mode
Eco drive mode controls the heating operation and fan speed of the air conditioning
system to enhance fuel efficiency. If the driving mode select switch is switched to Eco
drive mode in cold temperatures, the seat heater will be automatically operated to
assist heating performance.
■Sport mode automatic deactivation
Sport mode is automatically deactivated if the engine switch is turned off after driv-
ing in sport mode.
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4-5. Using the driving support systems
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
◆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 controlling 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 5 6
◆VGRS (Variable Gear Rati o Steering) (if equipped)
Adjusts the front wheel turning angle in accordance with the vehicle
speed and steering wheel movement
To help enhance driving safety and 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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2494-5. Using the driving support systems
4
Driving
◆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 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. 245)
◆LDH (Lexus Dynamic Handling 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 accordance with the steering wheel opera-
tion and vehicle speed
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, 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. 2 5 8
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4-5. Using the driving support systems
The slip indicator light will flash
while the TRAC/VSC systems are
operating.
If the vehicle gets stuck in fresh snow or mud, the TRAC/VSC systems
may reduce power from the engine to the wheels. You may need to turn
the system off to enable you to rock the vehicle in order to free it.
■Turning off the TRAC system only
To turn the TRAC system off,
quickly press and release the
switch.
The “TRAC OFF” will be shown on
the multi-information display. Press
the switch again to turn the system
back on.
When the TRAC/VSC systems are operating
Disabling the TRAC/VSC systems
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GS350_OM_OM30F69U_(U)
2514-5. Using the driving support systems
4
Driving
■Turning off both TRAC/VSC systems
To turn the TRAC/VSC systems
off, press and hold the switch for
3 seconds and more while the
vehicle is stopped.
The VSC OFF indicator light will
come on and the “TRAC OFF” will
be shown on the multi-information
display.
Press the switch again to turn the
systems back on.
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4-5. Using the driving support systems
■When the message is displayed on the multi-information display showing that
TRAC has been disabled even if the VSC OFF switch has not been pressed
TRAC cannot be operated. Contact your Lexus dealer.
■VGRS is disabled when
VGRS may stop operating in the following situations.
In this event, the steering wheel may move from its straight forward position, but it
will return when the system restarts.
●The steering wheel is operated for an extended period of time while the vehicle is
stopped or is moving very slowly.
●When force is continuously applied for a long time with the steering wheel turned
as far as it will go.
The center position of the steering wheel may change when VGRS is disabled. How-
ever, the position will return to normal after VGRS is reactivated.
■When the battery is disconnected
The steering wheel may move from its straight forward position, but this will be cor-
rected automatically when driving.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and VGRS sys-
tems
●A sound may be heard from the engine compartment when the engine is started or
just after the vehicle begins to move. This sound does not indicate that a malfunc-
tion has occurred in any of these systems.
●Any of the following conditions may occur 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 slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Reactivation of the TRAC/VSC systems
Even after the TRAC/VSC systems have been turned off, turning the engine off and
then on again will automatically reactivate the TRAC/VSC systems.
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2534-5. Using the driving support systems
4
Driving
■Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehi-
cle speed increases. However, when both TRAC/VSC systems are turned off, the
systems will not turn on even when vehicle speed increases.
■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 engine 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.
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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 vehicle stability and driving force, do not turn
the TRAC/VSC systems off unless necessary.
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