2011 LEXUS RX350 Owners Manual

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2-4. Using other driving systems
2

When driving
Disabling the TRAC/VSC systems
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.
nTurning off the TRAC system only
To turn the TRAC system off,
quickly press and release the
switch.
A message will be shown on the
multi-information display.
Press the switch again to turn the
system back on.
nTurning off both TRAC and VSC systems
To turn the TRAC and VSC sys-
tems off, press and hold the switch
for more than 3 seconds while the
vehicle is stopped.
A message will be shown on the
multi-information display and VSC
off indicator light will come on.
Press the switch again to turn the
systems back on.

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2-4. Using other driving systems
nSounds and vibrations caused by the ABS, brake assist, VSC and TRAC systems
lA 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 malfunction has occurred in any of these systems.
lAny of the following conditions may occur when the above systems are operat-
ing. None of these indicates that a malfunction has occurred.

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2-4. Using other driving systems
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When driving
CAUTION
nThe ABS does not operate effectively when
lTires with inadequate gripping ability are used (such as excessively worn tires on
a snow covered road).
lThe vehicle hydroplanes while driving at high speed on a wet or slick road.
nStopping distance when the ABS is operating will 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 in the following situations:
lWhen driving on dirt, gravel or snow-covered roads
lWhen driving with tire chains
lWhen driving over bumps in the road
lWhen driving over roads with potholes or roads with uneven surfaces
nTRAC 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.
Do not drive the vehicle in conditions where stability and power may be lost.

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2-4. Using other driving systems
CAUTION
nWhen the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
nWhen 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 ensure vehicle stability and driving force, do not turn the
TRAC/VSC systems off unless necessary.
nReplacing tires
Make sure that all tires are of the same 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 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.
nHandling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause a system malfunction.

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When driving
All-wheel drive lock switch (AWD models)
nAll-wheel drive lock mode
lAll-wheel drive lock mode is canceled when the brakes are applied to ensure
the ABS and VSC systems operate effectively.
lAll-wheel drive lock mode is canceled when the vehicle speed exceeds 25 mph
(40 km/h).
All-wheel drive lock mode can be used when a large amount of drive power
needs to be applied to all the wheels, such as when the vehicle gets stuck in
mud and you need to free it.
Press the switch.
The torque of the engine is dis-
tributed to the rear wheels to
the maximum extent possible in
accordance with driving condi-
tions.
Pressing the switch again can-
cels all-wheel drive lock mode
and returns the active torque
control 4WD system to normal
mode. (→P. 2 3 1 )

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2-4. Using other driving systems
Hill-start assist control
nHill-start assist control can be operated when
lThe shift lever is in a position other than P.
lThe parking brake is not applied.
lThe accelerator pedal is not depressed.
nHill-start assist control
lWhile 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.
lHill-start assist control operates for about 2 seconds after the brake pedal is
released.
lIf 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 sys-
tem still does not operate, check if the operating conditions explained above
have been met.
Hill-start assist control helps to prevent the vehicle from rolling backwards
when starting on an incline or slippery slope.
To engage hill-start assist con-
trol, further depress the brake
pedal when the vehicle is
stopped completely.
A buzzer will sound once to
indicate the system is activated.
The slip indicator will also start
flashing.

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When driving
nHill-start assist control buzzer
lWhen hill-start assist control is activated, the buzzer will sound once.
lIn the following situations, hill-start assist control will be canceled and the
buzzer will sound twice.

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2-4. Using other driving systems
Pre-Collision System
∗
Radar sensor
The radar sensor detects vehicles
or other obstacles on or near the
road ahead and determines
whether a collision is imminent
based on the position, speed, and
heading of the obstacles.
∗: If equipped
When the radar sensor detects the possibility of a frontal collision, pre-col-
lision system such as the brake assist and seat belts are automatically
engaged to lessen impact and injuries to occupants as well as vehicle dam-
age.
nPre-collision seat belts (front seat belt only)
If the pre-collision sensor detects that a collision is unavoidable, the pre-
collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or loses
control of the vehicle. (→P. 7 8 )
However, the system will not operate in the event of skidding when the
VSC system is disabled.
nPre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.