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

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.

STARTING AND DRIVING
398
CAUTION
Under certain conditions where the vehicle in front
slows drastically, or is stopped, the dynamic radar
cruise control will neither warn you nor decelerate. The
driver must depress the brake pedal to slow down,
ensuring collision avoidance or that sufficient
vehicletovehicle distance is maintained.
When vehicle−to−vehicle distance control mode is activated,
you must still be attentive to road and traf fic conditions. Should
your vehicle speed decrease below about 40 km/h (25 mph),
the dynamic radar cruise control will shut off, requiring you to
apply the brakes to slow. When a vehicle ahead slows
suddenly, stops or a vehicle cuts in front, the system may slow
your vehicle abruptly, but the automatic braking will cease if the
speed decreases below about 40 km/h (25 mph) requiring the
driver’s manual application of brakes.
CAUTION
Certain conditions make vehicle detection difficult or
impossible.
 As this system operates by detecting primarily the
reflected wave from the rear end of the vehicle ahead,
the distance cannot be accurately detected in the
following cases, resulting in improper
vehicletovehicle distance.
♦ The rear section of the vehicle ahead is extremely
small such as an unloaded trailer.
♦ The vehicle ahead or other vehicles around you
are flinging up water or snow.
♦ Heavy luggage which is loaded in your trunk or on
top of your rear seats is raising up the nose of your
vehicle.
 The millimeter wave radar sensor automatically
detects dirt if it is sticking to the front of the sensor
or cover of your vehicle, and if detected, a message
appears on the multiinformation display. However,
if the sensor or cover is covered with a metallic vinyl
bag, icicle, snowflakes, etc., dirt may not be detected,
resulting in improper vehicletovehicle distance.
Continue driving with due care to the vehicle ahead.
If dirt is detected, the dynamic radar cruise control
function is automatically cancelled. Always keep the
sensor and cover clean.

STARTING AND DRIVING
399
Dynamic radar cruise control should not be used in the
following conditions, to avoid death or serious injury.
In bad weather (such as rain, fog, snow , sandstorms,
or when raindrops or snowflakes get in the millimeter
wave radar sensor or the cover), the
vehicletovehicle distance will not be measured
accurately.
If the wipers are operated at high speed (including the
high speed operation with the wiper lever in the
“AUTO” position), dynamic radar cruise control is
automatically cancelled. (In the case of the low speed
operation and intermittent wiper operation, it is not
cancelled.) Dynamic radar cruise control is
automatically cancelled when the measurement is
extremely unstable due to bad weather.
 On the roads in heavy traffic or at sharp bends:
As an appropriate speed cannot be maintained, death
or serious injury could result.
 On slippery road surfaces (icy or snowcovered road
surfaces):
The tires will race and you will be unable to control.On steep downhill slopes:
If there is no vehicle detected ahead, the preset speed
will be easily exceeded because of inefficient engine
braking, resulting in death or serious injury. (In this
case, automatic braking will not work.) If there is a
vehicle detected ahead, the delay in deceleration
timing could cause death or serious injury.
 When the warning tone sounds frequently (because
acceleration or deceleration was repeated or
sufficient vehicletovehicle distance was not
maintained), an appropriate vehicle speed cannot be
attained, resulting in death or serious injury.
 On roads with steep and short inclines and declines,
failure to detect the vehicle ahead will shorten the
distance between your vehicle and the vehicle ahead,
resulting in death or serious injury.

STARTING AND DRIVING
400
G31013
Dynamic radar cruise control should not be used in
circumstances which are inappropriate for any cruise control
such as entering freeway on−ramps or off −ramps.
CAUTION
The dynamic radar cruise control should not be used
when exiting from, or when entering or merging onto a
freeway. When you are following a slower moving
vehicle and exiting, the sensor does not detect the
vehicle and will accelerate to preset speed.
G31015
CAUTION
If other vehicles are driving outside of the millimeter
wave radar detection range, a delay in the detection
of the vehicle cutting in at short range or detection
failure of the motorcycle running on the side of the
same lane will occur. In this case, the dynamic radar
cruise control system will not function properly.
 When a slower vehicle in front of you leaves the lane,
the dynamic radar cruise control will no longer detect
a vehicle ahead and will attempt to accelerate the
vehicle to the faster preset speed.

STARTING AND DRIVING
401
(b) Turning the system on
G31011
To operate the dynamic radar cruise control, push the
“ON−
OFF” button. This turns the system on. When the
“CRUISE” indicator light in the instrument cluster comes on
and “RADAR READY” appears on the multi−information
display, you can now set your desired cruising speed and
vehicle −to−vehicle distance. Pushing the “ON −OFF” button
again will turn the system completely off and “CRUISE OFF”
will appear on the multi −information display.
When 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.
When the engine switch is turned off, all the preset data is
cleared. When you use the dynamic radar cruise control again,
you need to reset the data. The multi−
information display will return to the
vehicle −to−vehicle distance screen about 6 seconds after the
vehicle− to−vehicle distance screen has been changed to
another screen.
CAUTION
To avoid accidentally engaging the cruise control, keep
the “ONOFF” button off when not using the dynamic
radar cruise control.

STARTING AND DRIVING
402(c) Setting operation
G31014

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. 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. At this time, the
multi−information display indicates settings such as the preset
vehicle speed, whether a vehicle is present ahead and
selected vehicle −to−vehicle distance. If there is no vehicle
detected ahead, the dynamic radar cruise control screen does
not display the vehicle ahead. 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
control prior to acceleration.
You cannot set a desired speed if the master warning light
comes on, the warning tone sounds and the multi− information
display indicates a warning message such as “CRUISE NOT
AVAILABLE”, “CLEAN RADAR SENSOR” or “CHECK
CRUISE SYSTEM”. If any of the above messages appears on
the display, see “Vehicle −to−vehicle distance control mode
failure warning” on page 410.
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. If no
warning message appears on the display, when you turn the
“ON−OFF” button on again, the setting can be made.
You can change the dynamic radar cruise control screen to
another screen even while the warning message is displayed.

STARTING AND DRIVING
403
2Cancelling 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 display shows
“RADAR READY” and the dynamic radar 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 case, the preset speed automatically
cancels out. At this time, the multiinformation display
shows “RADAR READY” and the dynamic radar cruise
control enters the ready mode.
The vehicle speed falls below about 40 km/h (25 mph). (40
km/h (25 mph) is designated as a cancel speed.)
CAUTION
In this case, the warning tone reminds you that the
dynamic radar cruise control is cancelled and you must
apply the brakes to slow the vehicle.
In the following cases, the warning messages appear and
the preset speed automatically cancels out. When
dynamic radar cruise control is restored, the warning
messages turn off and dynamic radar cruise control
enters “RADAR READY” mode.
a. The slip indicator light blinks and a warning tone sounds.
(This occurs when the vehicle is about to skid.)
b. The driving pattern selector switch is set to snow mode.
c. The anti −lock brake system is activated by automatic
braking. (The warning tone sounds.)
d. The sensor does not operate properly because a foreign
matter sticks to the sensor.
e. The wipers are operated at high speed (including high
speed operation with the wiper lever in the “AUTO” position.)
NOTICE
If the preset speed automatically cancels out for other
than the above reasons, do not operate the dynamic
radar cruise control. Although it is no problem to
continue driving, have your vehicle checked by your
Lexus dealer at the earliest opportunity.