sensor Lexus GS430 2006 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2006 PROD. (OM30786U) Service Manual

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406
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.
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.

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409
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 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. 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.
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 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.

STARTING AND DRIVING
410In 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.
3 Resetting to a faster speed
Press the control lever upward in the ”+ RES” direction and
hold it. The displayed speed will increase in increments of 5
mph (for the U.S.A.) or 5 km/h (for Canada). Release the lever
when the desired speed is attained. The vehicle will gradually
increase to the displayed speed.
Depressing the accelerator pedal and pressing the control
lever downward in the “– SET” direction will not reset to a faster
speed. At this time the set speed falls by 5 mph (for the U.S.A.)
or 5 km/h (for Canada).
CAUTION
When the vehicletovehicle distance control is on (on
followup cruising), your cruising speed is regulated in
proportion to the speed of the vehicle ahead, so
increasing the preset vehicle speed using the control
lever does not accelerate the vehicle. However, if the
vehicle ahead leaves the lane, your cruising speed will
increase up to the preset speed because the preset
speed has been set higher using the control lever.
Confirm the setting on the multiinformation display.

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415
The approach warning may not turn on even if the
vehicle drives closer to the vehicle ahead in the
following conditions:
♦ Your vehicle and the vehicle ahead are cruising at
almost the same speed.
♦ The vehicle ahead is cruising at a faster speed than
yours. (The distance between the vehicles will
become longer.)
♦ Pay special attention to the very slow vehicle at the
end of the line in heavy traffic or at the tollgate.
♦ Immediately after the speed setting.
♦ The accelerator pedal is depressed or immediately
after the release of the accelerator pedal.(g) Millimeter wave radar sensor
G31019a
 1 Millimeter wave grille cover
2Millimeter wave radar sensor
The millimeter wave radar sensor is used for
vehicletovehicle distance control cruising. When the
millimeter wave radar sensor is disabled for some reason,
the warning message appears on the multiinformation
display. For details, see “Vehicletovehicle distance
control mode failure warning” on page 417.

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416
CAUTION
To ensure that the dynamic radar cruise control system
will function properly while driving, observe the
following:
Always keep the millimeter wave radar sensor and
grille cover clean. When cleaning, use a soft cloth
and be careful not to damage the sensor and grille
cover.
 Avoid strong impacts around the millimeter wave
radar sensor. An incorrect millimeter wave radar
sensor alignment will result in system malfunction.
A special device is required to adjust the millimeter
wave radar sensor alignment. Be sure to have the
sensor adjusted by your Lexus dealer.
 Do not disassemble the millimeter wave radar
sensor.
 Do not affix a sticker (including a transparent sticker)
or attach an accessory around the millimeter radar
sensor or the grille cover.
 Do not modify or paint the grille cover. When
replacing the grille cover, be sure to use a genuine
grille cover.
For vehicles sold in U.S.A.
FCC WARNING
Changes or modifications not expressly approved by the
party responsible for compliance could void the user’s
authority to operate the equipment.
FCC RF exposure information
This device complies with the FCC RF exposure
requirements.
For vehicles sold in Canada
Operation is subject to the following two conditions;
(1) this device may not cause interference, and
(2) this device must accept any interference received, including interference that may cause undesired
operation of the device.

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417
(h) Vehicletovehicle distance control mode failure
warning
G31020
If there is trouble
somewhere in the dynamic radar cruise
control while the vehicle −to−vehicle distance control mode is
on, the ”CRUISE” indicator light in the instrument cluster
flashes, the master warning light comes on and the warning
tone sounds, and one or more of the following warning
messages will appear on the multi −information display.
 “CLEAN RADAR SENSOR”
 “CRUISE NOT AVAILABLE”
 “CHECK CRUISE SYSTEM”
If any warning message shown above appears, the preset
speed automatically cancels out.
G13073
If the system cannot easily measure the
vehicletovehicle distance because of a dirty millimeter
wave radar sensor or grille cover while the dynamic radar
cruise control is on, the above message appears.
If this message appears, clean the sensor and grille cover with
a soft cloth and try setting the preset speed again. If the dirt
is removed without cleaning, the system will automatically
enter the “RADAR READY” mode. If the system does not enter
the “RADAR READY” mode even after cleaning or the
message remains on the display, the system might be
malfunctioning. Although it is no problem to continue driving,
contact your Lexus dealer.

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436
Install all 4 tires of specified size at appropriate
pressure: The antilock brake system detects vehicle
speeds using the speed sensors for respective wheels’
turning speeds. The use of tires other than specified
may fail to detect the accurate turning speed resulting
in a longer stopping distance.“ABS” warning light
G31080
 1 U.S.A. 2Canada
GS430—The light comes on when the engine switch is
selected in “IG −ON” mode. If the anti −lock brake system and
the brake assist system work properly, the light turns off in a
few seconds after the engine is started.
GS300—The light comes on for a few seconds when the
engine switch is selected in “IG −ON” mode. It indicates the
anti− lock brake system and the brake assist system work
properly.
If either system malfunctions, the light comes on again.
When the “ABS” warning light is on, the anti− lock brake system
and the brake assist system do not operate, but the brake
system still operates conventionally.

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450
Precollision sensor
The millimeter wave radar sensor detects vehicles or
objects near or on the road your vehicle is traveling and
determines the possibility of a collision based on the
object position, vehicle speeds and the course you are
traveling.
The pre− collision sensor will operate when the vehicle speed
is about 5 km/h (3 mph) or over.
G31019a
 1 Millimeter wave grille cover
2Millimeter wave radar sensor
The millimeter wave radar sensor is installed in the front grille
of the hood.
The millimeter wave radar sensor cannot detect plastic objects
such as pylons, and may not detect people, animals, bicycles,
motor cycles, trees, snowbanks, etc. as objects with which
your vehicle may collide.
CAUTION
To ensure that precollision system will function
properly while driving, observe the following. Failure to
follow these instructions could reduce the
effectiveness of the precollision system in case of
vehicle accident:
 Always keep the millimeter wave radar sensor and
grille cover clean. When cleaning, use a soft cloth
and be careful not to damage the sensor and grille
cover.
 Avoid strong impacts around the millimeter wave
radar sensor. An incorrect millimeter wave radar
sensor alignment will result in system malfunction.
A special device is required to adjust the millimeter
wave radar sensor alignment. Be sure to have the
sensor adjusted by your Lexus dealer.
 Do not disassemble the millimeter wave radar
sensor.
 Do not affix a sticker (including a transparent sticker)
or attach an accessory around the millimeter radar
sensor or the grille cover.
 Do not modify or paint the grille cover. When
replacing the grille cover, be sure to use a genuine
grille cover.

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451
Precollision seat belts (Front seat belts only)
When the precollision sensor detects an object or
vehicle with which your vehicle might collide and
determines that a collision may be unavoidable, the seat
belts are quickly drawn back by the retractors to enhance
the effects of the seat belt pretensioners. The
precollision seat belts also work as well when hard
braking.
The pre −collision seat belts will operate in the following
conditions:
 When the approaching speed in regard to the object or the
vehicle exceeds about 30 km/h (18 mph).
 When the front seat occupants wear the seat belts.
In the following conditions, the seat belts are quickly drawn
back by the retractors regardless of the possibility of the
collision:
 When the vehicle is spinning or cannot take a turn properly
at more than about 15 km/h (10 mph).
Precollision brake assist system
When the precollision sensor detects an object or
vehicle with which your vehicle might collide, and
determines that a collision may be unavoidable,
depressing the brake pedal provides more powerful
braking according to the amount of pedal depression.
The pre−collision brake assist system will operate when the
following all conditions are met.
 When the vehicle speed is about 30 km/h (18 mph) or over.
 When the brake pedal is depressed.
 When the approaching speed in regard to the object or the
vehicle exceeds about 30 km/h (18 mph).
If the brake pedal is kept depressed before the sensor’s
determination of unavoidable collision, the pre −collision brake
assist system will operate soon after the sensor’s
determination.

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Adaptive variable suspension control (GS430
only)
When the precollision sensor detects an object or
vehicle with which your vehicle may collide, and
determines that a collision may be unavoidable, the
adaptive variable suspension adjusts the damping effect
on the shock absorbers and regulates the vehicle not to
pitch forward so much.
The adaptive variable suspension will operate when the
following all conditions are met.
When the vehicle speed is about 5 km/h (3 mph) or over.
 When the approaching speed in regard to the object or the
vehicle exceeds about 30 km/h (18 mph).
Precollision system failure warning
G31079
Precollision system warning light
The light warns that there is a problem somewhere in the
precollision system.
The light comes on when the engine switch is selected in
“IG−ON” mode. If the system works properly, the light goes off
after a few seconds.
If the light does not come on when the engine switch is selected
in “IG−ON” mode, have your vehicle checked by your Lexus
dealer.
If the system has a problem, the pre− collision system warning
light comes on or blinks. At this time, the master warning light
comes on, a warning tone sounds, and either of the following
messages appears on the multi−information display.
 PCS DISABLED NOW
 CHECK PCS