2015 Lexus GS350 wheel

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GS350_OM_OM30F69U_(U)
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.

GS350_OM_OM30F69U_(U)
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.

GS350_OM_OM30F69U_(U)
2554-5. Using the driving support systems
4
Driving
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, TRAC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer 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.

GS350_OM_OM30F69U_(U)
2594-5. Using the driving support systems
4
Driving
◆Suspension control (if equipped)
When the system determines that there is a high possibility of a frontal
collision, the operation of AVS (P. 249) optimally controls the damp-
ing force of the shock absorber.
◆Steering control (if equipped)
Vehicles with VGRS
There is a high possibility of collision and if the steering wheel is oper-
ated, the steering gear ratio is changed by VGRS to help improve the
response to steering input.
Vehicles with LDH
There is a high possibility of collision and if the steering wheel is oper-
ated, the steering angles of the front and rear wheels and the heaviness
of the steering wheel are controlled by LDH, thus heightening respon-
siveness in response to the steering operation.
◆Driver monitor system (if equipped)
When the system determines that there is a possibility of a collision, and
either the driver is not facing forward or the driver’s eyes are closed,
PCS warnings are given in advance to warn the driver. If the system
determines that the conditions to operate pre-collision alert braking
have been met even when the possibility of a collision increases further,
pre-collision alert braking will operate.