2006 Lexus GS430 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2005 PROD. OWNER'S MANUAL (OM30649U)

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If the system malfunction is detected when dynamic radar
cruise control is in the “RADAR READY” mode or
operating, the above message appears.
If this message appears, stop your vehicle in a safe place, turn
the engine switch off, and then restart it to reset the system.
If the setting still cannot be made or the same message
appears again, the system might have malfunctioned.
Although it is no problem to continue driving, contact your
Lexus dealer.
NOTICE
While you are cruising with the dynamic radar cruise
control on, if the master warning light comes on, the
“CRUISE” indicator light flashes, “CHECK CRUISE
SYSTEM” appears on the multiinformation display and
the warning tone sounds, turn the engine switch off and
then on again. If the function is cancelled again after
setting or if settings cannot be made, the dynamic radar
cruise control system may be malfunctioning.
Although it is no problem to continue driving, have your
vehicle checked by your Lexus dealer.
Conventional (fixed speed) cruise control
mode
This mode allows you to cruise at a desired speed over
about 45 km/h (28 mph) with your foot off the accelerator
pedal.
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, the speed
will change more radically so it is better to drive without cruise
control.
When 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.

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CAUTION
In the conventional (fixed speed) cruise control
mode, an approach warning does not activate even if
you are too close to the vehicle ahead, as neither the
presence of the vehicle ahead nor the
vehicletovehicle distance is detected. Pay special
attention to the distance between your vehicle and
the vehicle ahead. Always confirm the setting in the
multiinformation display.
 The conventional (fixed speed) cruise control mode
of the dynamic radar cruise control should not be
used in the following conditions, which could result
in death or serious injury.
♦ To help maintain maximum control of your vehicle,
do not use fixed speed control mode when using
dynamic radar cruise control while driving in
heavy or varying traffic, or on slippery (rainy, icy
or snowcovered) or winding roads.
♦ Avoid vehicle speed increasing when driving
downhill. If the vehicle speed is too fast in relation
to the preset speed in the fixed speed control
mode, cancel the fixed control mode and then
downshift the transmission to use engine braking
to slow down.
(a) Turning the system on
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To operate conventional cruise control mode, push the
“ON−OFF” button. This turns the system on. The “CRUISE”
indicator light in the instrument cluster comes on and “RADAR
READY” appears on the multi −information display. Push the
control lever in the “MODE” direction for longer than 1 second
to change to conventional cruise control mode. The indicator
on the multi− information display is as shown. You can now set
your desired cruising speed. Pushing the “ON −OFF” button
again will turn the system completely off and “CRUISE OFF”
will appear on the multi −information display.
However, once the vehicle− to−vehicle distance control mode
activates and is used, it cannot be changed to the conventional
(fixed speed) cruise control mode using the above operation.
To change the mode, push the “ON −OFF” button to turn the
system off and then push it again to turn it on. Next push the
lever in the “MODE” direction for longer than about 1 second.

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414When the engine switch is turned off, the system is also
automatically turned off. To use the dynamic radar cruise
control again, push the “ON
−OFF” button again to turn it on.
CAUTION
To avoid accidentally engaging cruise control , keep the
“ONOFF” button off when not using dynamic radar
cruise control.
(b) Setting operation
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 Each function is described below.
1
Setting the desired speed
The transmission must be in “D”, “6” (sixth range), “5”\
(fifth
range) or “4” (fourth range) before you set the cruise control
speed in the conventional cruise control mode of the dynamic
radar cruise control.
After bringing 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 and the multi −information
display shows the preset speed. At this time, you may take
your foot off the accelerator pedal. If you need to accelerate
− for example, when passing − depress the accelerator pedal
enough for the vehicle to exceed the preset speed. When you
release the accelerator pedal, the vehicle will return to the
speed set prior to acceleration.

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You cannot set a desired speed if the master warning light
comes
on, the warning tone sounds and the multi− information
display indicates a warnin g message such as “CHECK
CRUISE SYSTEM”. If this messages appears on the display,
see “Conventional cruise control mode failure warning” on
page 417.
If you turn off the “ON−OFF” button while the warning message
is displayed, the warning message turns off and the
multi−information display switches to another screen. When
you turn the “ON− OFF” button on again, the warning message
comes back on the display. If no warning message appears on
the display, the setting can be made.
You can change the dynamic radar cruise control screen to
another screen even while the warning message is displayed.
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 cancelled by a. or b., the multi−information displays shows
nothing and the conventional cruise control enters the ready
mode.
If cancelled by c., the “CRUISE” indicator light goes off in the
instrument cluster and the multi −information display shows
“CRUISE OFF”. In this case, the preset speed data is cleared,
and you must set the speed from the beginning. In the following cases, the preset speed automatically
cancels out:
a. The vehicle speed falls below about 40km/h (25 mph).
b. If the vehicle speed drops 16 km/h (10 mph) below the
preset speed, the preset speed will also automatically be
cancelled.
c. The control lever is presse
d downward in the “– SET”
direction and held at less than about 45 km/h (28 mph). (45
km/h (28 mph) is designated as a lower preset speed limit .)
If the vehicle speed falls below about 40 km/h (25 mph), the
preset speed data is cleared and you must set the speed from
the beginning.
If cancelled by the above cases, the multi −information display
shows nothing and the conventional cruise control enters the
ready mode.
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.

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3Resetting 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.
A quicker way to reset the speed is to accelerate and then
press the control lever downward in the “– SET” direction. 4 Resetting to a slower speed
Press the co ntrol 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.
A quicker way to reset the preset speed is to depress the brake
pedal and then press the control lever downward in the “– SET”
direction.
Even if you downshift the transmission from the “D” or “6” (\
sixth
range) to “5” (fifth range), or from “D” or “5” (f\
ifth range) to “4”
(fourth range) in the conventional cruise control mode, engine
braking will not be applied because this mode is not cancelled.
To slow down, reset the cruise control to a slower speed with
the cruise control lever or depress the brake pedal. If you use
the brake pedal, cruise control is cancelled.

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5Resuming 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.
(c) Conventional cruise control mode failure warning
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If the system malfunction is detected when the
conventional cruise control mode is in the ready mode or
operating, the master warning light comes on, a warning
tone sounds and the above message appears.
If this message appears, push the “ON− OFF” button to turn the
system off and then push it again to turn it on. If the setting still
cannot be made or the same message appears again, the
system might have malfunctioned. Although it is no problem
to continue driving, contact your Lexus dealer.
ADAPTIVE VARIABLE SUSPENSION SYSTEM (GS430 only)
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 1Sport position 2Normal position
The adaptive variable suspension system controls
suspension and steering, and ensures optimum vehicle
posture and steering capabilities depending on the
driving condition.
Sport mode: Suitable for sporty type driving, such as on
winding mountain roads and high speed driving.
Normal mode: Suitable for ordinary driving.
To turn on the sport mode, push the selector switch on the
“SPORT” side. The indicator comes on in the instrument
cluster.
To change to the normal mode, push the switch to the “NORM”
side.

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TRACTION CONTROL SYSTEM
The traction control system automatically helps prevent
the spinning of rear wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the engine switch is selected in “IG−ON” mode, the
system automatically turns on.
CAUTION
Under certain slippery road conditions, full traction of
the vehicle and power against rear wheels cannot be
maintained, even though the traction control system is
in operation. Do not drive the vehicle under any speed
or maneuvering conditions which may cause the
vehicle to lose traction control. In situations where the
road surface is covered with ice or snow, your vehicle
should be fitted with snow tires or tire chains. Always
drive at an appropriate and cautious speed for the
present road conditions.
G31038
 Slip indicator light
Leave the system on during the ordinary driving so that it
can operate when needed.
You may hear a sound in the engine compartment for a few
seconds just after the vehicle begins to move. This means that
the traction control system is in the self −check mode, but does
not indicate a malfunction.
When the traction control system is operating, the following
conditions occur:
 The system controls the spinning of the rear wheels. At this
time, the slip indicator light blinks.
 You may feel vibration or noise in your vehicle, caused by
operation of the brakes. This indicates the system is
functioning properly.
GS430—The slip indicator light comes on when the engine
switch is selected in “IG− ON” mode. The light goes off when
the engine is started.

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GS300—The slip indicator light comes on for a few seconds
when the engine switch is selected in “IG
−ON” mode.
If the indicator light does not come on when the engine switch
is selected in “IG −ON” mode, contact your Lexus dealer.
Traction control off mode
(twowheel drive models only)
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If your wheels get stuck in a ditch when you are driving on
a severe off road and sand, turn off the traction control
system. This system that controls engine performance
interferes with the process of freeing your wheels.
To turn off: Push “TRAC OFF” switch.
The slip indicator light will come on.
The vehicle stability control system is always activated even if
the traction control system is turned off. GS430
only—When the vehicle speed exceeds about 50 km/h
(30 mph) even if the traction control system is turned off, the
system turns on automatically.
To turn on: Push “TRAC OFF” switch once again.
The slip indicator light will go off.
In the following cases, contact your Lexus dealer:
 The slip indicator light does not come on when the engine
switch is selected in “IG −ON” mode.
 The slip indicator light remains on after the engine is started
(GS430), or remains on after the engine switch is selected
in “IG− ON” mode (GS300).
 The slip indicator light comes on in the normal driving mode
while driving.