2006 Lexus GS430 cruise control

SECTION 3 – 1
339
STARTING AND DRIVING
Starting and driving
Three−way catalytic converters340
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Engine exhaust caution 341
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Operating the engine switch 342
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Parking brake 352
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Automatic transmission 353
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Electronic throttle control system 364
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Intuitive parking assist 365
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Rear view monitor system 388
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Cruise control 392
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Dynamic radar cruise control 395
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Adaptive variable suspension system 417
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Traction control system 418
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Vehicle stability control system 420
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Hill −start assist control system 422
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Variable gear ratio steering system 424
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Vehicle dynamics integrated management 426
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Brake system 427
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Brake pad wear limit indicators 431
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Electric power steering system 432
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Tire pressure warning system 433
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Pre−collision system 443
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STARTING AND DRIVING
360When
the cruise control is being used, even if you downshift
from “D” or “6” (sixth range) to “5” (fifth range)\
, engine
braking will not be enabled because the cruise control is not
cancelled. For vehicle speed reduction, see page 394.
Vehicles with the dynamic radar cruise control —
When the cruise control is being used in the conventional
(fixed speed) cruise control mode or in the
vehicle −to−vehicle distance control mode, even if you
downshift from “D” or “6” (sixth range) to “5” (fif\
th range),
engine braking will not be enabled because the cruise
control is not cancelled. For vehicle speed reduction, see
pages 416 and 404.
 Shift into the “4” (fourth range) position. The transmission
will downshift to fourth gear when the vehicle speed is or
becomes lower than the speed listed below and more
powerful engine braking will be enabled.
GS430 193 km/h (120 mph)
GS300 (2WD) 187 km/h (116 mph)
GS300 (4WD) 178 km/h (111 mph)
If you drive in the “D” position: Shift the selector lever to
the “S” position and shift the lever down to the “–” posi\
tion
once to select “4” (fourth range). However, when you move
the lever to the “S” position while the AI shifting control is
operating, the first shift range will be “5” (fifth range), “4”
(fourth range) or “3” (third range) because the suitable shift
range is selected depending on the driving condition.
If you drive in the “S” position: Shift the selector lever
down to the “–” position to select the “4” (fourth range\
). When
the cruise control is being used, even if you downshift
from “D” or “5” (fifth range) to “4” (fourth range)\
, engine
braking will not be enabled because the cruise control is not
cancelled. For vehicle speed reduction, see page 394.
Vehicles with the dynamic radar cruise control —
When the cruise control is being used in the conventional
(fixed speed) cruise control mode or in the
vehicle −to−vehicle distance control mode, even if you
downshift from “D” or “5” (fifth range) to “4” (fourth range),
engine braking will not be enabled because the cruise
control is not cancelled. For vehicle speed reduction, see
pages 416 and 404.
 Shift into the “3” (third range) position. The transmission will
downshift to third gear when the vehicle speed is or
becomes lower than the speed listed below and more
powerful engine braking will be enabled.
GS430 144 km/h (90 mph)
GS300 (2WD) 135 km/h (84 mph)
GS300 (4WD) 129 km/h (80 mph)
If you drive in the “D” position: Shift the selector lever to
the “S” position and shift the lever down to the “–” posi\
tion
twice to select the “3” (third range). However, when you
move the lever to the “S” position while the AI shifting control
is operating, the first shift range will be “5” (fifth range), “\
4”
(fourth range) or “3” (third range) because the suitable shift
range is selected depending on the driving condition.
If you drive in the “S” position: Shift the selector lever
down to the “–” position to select “3” (third range).

STARTING AND DRIVING
392
CRUISE CONTROL
The cruise control allows you to cruise the vehicle at a
desired speed over 40 km/h (25 mph) with your foot off the
accelerator pedal.
Your cruising speed can be maintained although a slight speed
change may occur when driving up or down a gradient, within
the limits of engine performance. On steeper hills, a great
speed change will occur so it is better to drive without the cruise
control.
When the cruise control is on, the driving pattern of the
automatic transmission is fixed in the normal mode, regardless
of the position of the selector switch.
CAUTION
 To help maintain maximum control of your vehicle,
do not use the cruise control when driving in heavy
or varying traffic, or on slippery (rainy, icy or
snowcovered) or winding roads.
 Avoid vehicle speed increases when driving
downhill. If the vehicle speed is too fast in relation to
the cruise control set speed, cancel the cruise
control then downshift the transmission to use
engine braking to slow down.
Turning the system on
G31163
To operate the cruise control, push the “ON −OFF” button. This
turns the system on. The indicator light in the instrument
cluster shows that you can now set your desired cruising
speed. Another push on the button will turn the system
completely off.
When the engine switch is turned off, the “ON −OFF” button is
also automatically turned off. To use the cruise control again,
push the “ON −OFF” button again to turn it on.
CAUTION
To avoid accidental cruise control engagement, keep
the “ONOFF” button off when not using the cruise
control.

STARTING AND DRIVING
393
Setting operation
G31164
Each function is described below.
1
Setting at a desired speed.
The transmission must be in the “D” position, or the shift range
position must be “4” (fourth range), “5” (fifth range) o\
r “6” (sixth
range) in the “S” mode before you set the cruise control speed.
Bring the vehicle to the desired speed, press the control lever
downward in the “– SET” direction and release it. This sets the
vehicle at that speed. Now you may take your foot off the
accelerator pedal. If you need acceleration − for example,
when passing − depress the accelerator pedal enough for the
vehicle to exceed the set speed. When you release the
accelerator p edal, the vehicle will return to the speed set prior
to the acceleration.
2 Cancelling the preset speed
You can cancel the preset speed by doing any of the following:
a. Pulling the control lever in the ”CANCEL” direction.
b. Depressing the brake pedal.
c. Pushing the “ON −OFF” button.
If the vehicle speed falls below about 40 km/h (25 mph), the
preset speed will be automatically cancelled.
If the vehicle speed drops 16 km/h (10 mph) below the preset
speed, the preset speed will also automatically be cancelled.
If the slip indicator light blinks and a warning tone sounds, the
preset speed will be automatically cancelled.
If the preset speed automatically cancels out for other than the
above reasons, do not operate the cruise control. Although it
is no problem to continue driving, have your vehicle checked
by your Lexus dealer at the earliest opportunity.
3 Resetting to a faster speed
Press the control lever upward in the “+ RES” direction and
hold it. Release the lever when the desired speed is attained.
While the lever is held upward, the vehicle will gradually gain
speed.
When the difference between the actual vehicle speed and the
set speed is less than 5 km/h (3 mph), the set speed can be
increased 1.6 km/h (1 mph) each time by pressing the control
lever upward in the “+ RES” direction quickly within 0.6
seconds.

STARTING AND DRIVING
394However, a quicker way to reset is to accelerate the vehicle
and then press the control lever downward in the “– SET”
direction.
4
Resetting to a slower speed
Press the control lever downward in the “– SET” direction and
hold it. Release the lever when the desired speed is attained.
While the lever is held downward, the vehicle speed will
gradually decrease.
When the difference between the actual vehicle speed and the
set speed is less than 5 km/h (3 mph), the set speed can be
lowered 1.6 km/h (1 mph) each time by pressing the control
lever downward in the “– SET” direction quickly within 0.6
seconds.
However, a quicker way to reset is to depress the brake pedal
and then press the control lever downward in the “– SET”
direction.
With the cruise control on, even if you downshift the
transmission from the “D” position or “6” (sixth range) to the “5”\
(fifth range), or from the “D” position or “5” (fifth ran\
ge) to the
“4” (fourth range), engine braking will not be enabled because
the cruise control is not cancelled. To decrease the vehicle
speed, reset to a slower speed with the cruise control lever or
depress the brake pedal. If you use the brake pedal, cruise
control is cancelled.
5 Resuming the preset speed
If the preset speed is cancelled by pulling the control lever, by
depressing the brake pedal or vehicle stability control
activation, pushing the lever up in the “+ RES” direction will
restore the speed set prior to cancellation. However, once the
vehicle speed falls below about 40 km/h (25 mph), the preset
speed will not be resumed.
Cruise control failure warning
If the “CRUISE” indicator light in the instrument cluster flashes
when using the cruise control, push the “ON −OFF” button to
turn the system off and then push it again to turn it on.
If any of the following conditions then occurs, there is some
trouble in the cruise control system.
 The indicator light does not come on.
 The indicator light flashes again.
 The indicator light goes out after it comes on.
If this is the case, contact your Lexus dealer and have your
Lexus inspected.

STARTING AND DRIVING
395
DYNAMIC RADAR CRUISECONTROL
The vehicles with precollision system are equipped with
dynamic radar cruise control.
Dynamic radar cruise control allows you to drive at a
selected cruising speed over about 45 km/h (28 mph) with
your foot off the accelerator pedal, maintaining an
appropriate vehicletovehicle distance.
CAUTION
Do not rely excessively on dynamic radar cruise control
in order to avoid serious injury or death, or to prevent
accidents or to control the vehicle’s speed in
emergency situations. Do not use cruise control except
in appropriate road and traffic conditions. Always drive
carefully and attentively. Before using dynamic radar
cruise control, read and understand the following
instructions.
G31009
 1 Multiinformation display
2Master warning light
3“CRUISE” indicator light
4Distance switch
(for changing vehicletovehicle distance)
5 Cruise control switch

STARTING AND DRIVING
396
Changing the dynamic radar cruise control
mode
G31010
 1Vehicletovehicle distance control mode
2Conventional (fixed speed) cruise control mode
The dynamic radar cruise control function has two cruise
control modes.
 Vehicle −to−vehicle distance control mode for maintaining
an appropriate distance between vehicles
 Conventional (fixed speed) cruise control mode for cruising
at preset speeds
You can change the mode by using the control lever.
The two cruise control modes function differently. If you use
dynamic radar cruise control, always confirm which mode is
selected.
Vehicletovehicle distance control mode
The millimeter wave radar sensor in this system primarily
detects the reflected wave from the rear end of the vehicle
ahead of you to determine the presence of the vehicle
ahead as well as measuring the vehicletovehicle
distance. The detection range of the sensor is about 120
m (400 ft.) ahead.
When the dynamic radar cruise control is on, the driving
pattern of the automatic transmission is fixed in the normal
mode, regardless of the position of the selector switch.
CAUTION
The dynamic radar cruise control is not a
collisionavoidance system and will not prevent
accidents. The dynamic radar cruise control is a vehicle
speed control device that is intended for use only on
freeways or roads where the traffic is light or moderate.
To avoid serious injury, you must use caution and be
attentive to road and traffic conditions while using
dynamic radar cruise control.

STARTING AND DRIVING
397
(a) Dynamic radar cruise control operations
G31012
The dynamic radar cruise control function operates
automatically and depending on whether a vehicle is
detected ahead
may change the speed of your vehicle as
follows: If no vehicle is running ahead of you:
1
Cruising at a fixed speed: If there is no vehicle detected
ahead, your cruising speed is maintained at the preset
speed from about 45 km/h (28 mph) to about 135 km/h (85
mph). The preset speed is displayed in the
multi−information display. For the vehicle speed setting,
see “Setting operation ” on page 402.
If a vehicle is detected ahead of you:
2 Deceleration cruising function: If a slower moving
vehicle is detected ahead of you, your vehicle cruising
speed decreases within the range of about 40 km/h (25
mph) to about 135 km/h (85 mph). The multi− information
display shows the preset speed, the detected vehicle
ahead and selected vehicle− to−vehicle distance. If your
vehicle gets closer to the vehicle ahead because of
insufficient automatic deceleration, then the warning tone
warns you to also manually apply brakes.
3 Followup cruising function: After deceleration, your
vehicle cruising speed changes in proportion to the speed
of the vehicle ahead to maintain an appropriate distance
from your vehicle to the vehicle ahead. The
vehicle −to−vehicle distance can be changed. For details,
see “Changing vehicle −to−vehicle distance setting” on
page 406.
4 Acceleration cruising function: If the vehicle ahead
changes lanes, your vehicle cruising speed will be
gradually increased up to the preset speed, and your
vehicle resumes fixed− speed cruising.