2014 Lexus GS250 Owner's Manual

3214-5. Using the driving support systems
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Driving
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◆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. 317)
◆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 sur-
faces by controlling the brakes, engine output, steering assist, and
steering ratio
◆PCS (Pre-Crash Safety system) (if equipped)
→ P. 3 3 0
◆Emergency brake signal
When the brakes are applied suddenly, the stop lights automatically
flash to alert the vehicle behind.
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3224-5. Using the driving support systems
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The slip indicator light will flash
while the TRC/VSC systems are
operating.
If the vehicle gets stuck in fresh snow or mud, the TRC and 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 TRC system only
To turn the TRC system off,
quickly press and release the
switch.
The “TRC OFF” will be shown on
the multi-information display. Press
the switch again to turn the system
back on.
When the TRC/VSC systems are operating
Disabling the TRC/VSC systems
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3234-5. Using the driving support systems
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■Turning off both TRC and VSC systems
To turn the TRC and VSC sys-
tems off, press and hold the but-
ton for 3 seconds and more while
the vehicle is stopped.
The VSC OFF indicator light will
come on and the “TRC OFF” will
be shown on the multi-information
display.
Press the button again to turn the
systems back on.
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3244-5. Using the driving support systems
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■When the message is displayed on the multi-information display showing that TRC
has been disabled even if the VSC OFF switch has not been pressed
TRC 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 and TRC systems
●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 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 TRC/VSC systems
Even after the TRC/VSC systems have been turned off, turning the engine off and
then on again will automatically reactivate the TRC/VSC systems.
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3254-5. Using the driving support systems
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■Reactivation of the TRC system linked to vehicle speed
When only the TRC system is turned off, the TRC system will turn on when vehicle
speed increases. However, when both TRC and VSC systems are turned off, the sys-
tems 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.
■Operating conditions of emergency brake signal
When the following three conditions are met, the emergency brake signal will oper-
ate:
●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
vehicle 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 oper-
ation.
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3264-5. Using the driving support systems
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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
■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.
■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 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.
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3274-5. Using the driving support systems
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CAUTION
■Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire
inflation pressure level.
The ABS, TRC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional for further information when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will affect the
driving assist systems, and may cause a system to malfunction.
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3284-5. Using the driving support systems
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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 pedal 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 tempo rarily 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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