2010 Lexus HS250h Basic Information Before Operation / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

209
2-4. Using other driving systems
2
When driving
Driving in vehicle-to-vehicle distance control mode
This mode employs a sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead and to judge the distance between
your vehicle and those the vehicle ahead of you.
Note that vehicle-to-vehicle distance will close in when traveling on long
downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehi-
cle distance can also be set by operating the vehicle-to-vehicle distance con -
trol.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automatically
decelerates your vehicle. When a grea ter reduction in vehicle speed is nec-
essary, the system applies the brakes. A warning tone warns you when the
s
ystem cannot decelerate sufficiently to prevent your vehicle from closing in
on the vehicle ahead.

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2-4. Using other driving systems
Example of follow-up cruising 
When following a vehicle driving slower than the set speed
The system continues follow-up cruising while adjusting for changes in the
speed of the vehicle ahead in order to maintain the vehicle-to-vehicle dis -
tance set by the driver.
Example of acceleration 
When there are no longer any vehicles ahead driving slo
wer than the
set speed.
The system accelerates until the set speed is reached. The system then
returns to constant speed cruising.
Approach warning
When your vehicle is too close to a vehicle ahead, and sufficient auto-
matic deceleration via th e cruise contr
ol is not possible, the display will
flash and the buzzer will so und to alert the driver. An example of this
would be if another driver cuts in fron t of you while you are following a
vehicle. Apply the brakes to ensure an appropriate vehicle-to-vehicle dis -
tance.

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2-4. Using other driving systems
2
When driving
Selecting conventional constant speed control mode
Dynamic radar cruise control can be used as conventional cruise control
if you select constant speed control mode.
Press the “ON-OFF” button to
activate the cruise control.
Press the button again to deacti-
vate the cruise control.
Vehicle-to-vehicle distance con -
trol mode is always reset when the
“PO
WER” switch is turned to ON
mode.
Switch to constant speed con -
trol mode. 
(Push the lever forward and
hold for appr
oximately one sec -
ond.)
Constant speed control mode indi-
cator will come on.
Adjusting the speed setting:

P. 2 0 7
Canceling and resuming the speed
se
tting:
P. 2 0 8

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2-4. Using other driving systems
■Dynamic radar cruise can be set when
●The shift position is in D.
●Vehicle speed is above approximately 30 mph (50 km/h).
■Switching modes
The mode cannot be switched to constant speed
control mode if vehicle-to-vehicle
distance control mode has been used. Th e mode also cannot be switched from
constant speed control to vehicle-to-vehic le distance control mode. Turn the sys-
tem off by pressing the “ON-OFF” bu
tton, and turn it on again.
■Accelerating
The vehicle can be accelerated normally. After acceleration, the set speed resume.
Ho

wever, during vehicle-to-vehicle distance control mode, the vehicle speed may
decrease below the set speed in order to maintain the distance to the vehicle
ahead.
■Automatic cancellation of vehicle-to-vehicle distance control
Vehicle-to-vehicle distance control driving is automatically canceled in the follow -
ing situations:
●Actual vehicle speed falls below approximately 25 mph (40 km/h).
●VSC is activated.
●The sensor cannot operate correctly because it is covered in some way.
●The windshield wipers are operating at high speed.
If vehicle-to-vehicle distance control driving is automatically canceled for any other
r
eason, there may be a malfunction in the system. Contact your Lexus dealer.
■Automatic cancellation of constant speed control
The cruise control will stop maintaining the vehicle speed in the following situations:
●Actual vehicle speed is more than approximately 10 mph (16 km/h) below the
set vehicle speed.
At this time, the memorized set speed is not retained.
●Vehicle speed falls below approximately 25 mph (40 km/h).
VSC is activated.

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2-4. Using other driving systems
2
When driving
■Vehicle-to-vehicle distance settings
Select a distance from the table below. Note that the distances shown correspond
to a vehicle speed of 50 mph (80 km/h). Vehicle-to-vehicle distance increases/
decreases in accordance with vehicle speed.
■Radar sensor and grille cover
Always keep the sensor and grille cover clean to ensure that the vehicle-to-vehicle
distance control operates properly. (Some obstructions, such as snow, ice and plas-
tic objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is canc eled if an obstruction is detected.
■Warning lights, messages and buzzer s for dynamic radar cruise control
Warning lights, messages and buzzers are us ed to indicate a system malfunction or
to inform the driver of the need for caution while driving. ( P. 493, 502, 505)
■Approach warning
In the following instances, there is a possibility that the warnings will not occur:
●When the speed of the vehicle ahead ma tches or exceeds your vehicle speed
●When the vehicle ahead is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●At the instant the accelerator is applied
Distance optionsVehicle-to-vehicle distance
LongApproximately 160 f t. (50 m)
MediumApproximately 130 ft. (40 m)
ShortApproximately 100 f t. (30 m)
Grille cover
Radar sensor

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2-4. Using other driving systems
■Certification
For vehicles sold in the U.S.A.
FCC ID: HYQDNMWR004
This device complies with Part 15 of the FCC Rules. Operation is subject to the fol-
lowing two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may
cause undesired operation.
FCC WARNING
Changes or modifications not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
Radio frequency radiation exposure Information:
This equipment complies with FCC radiatio n exposure limits set forth for an uncon-
trolled environment.
This equipment should be installed and op erated with minimum distance of 20 cm
between the radiator (antenna) and your body.
This transmitter must not be co-located or operating in conjunction with any other
antenna or transmitter.
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicl e-to-vehicle distance control. 
Be aware of the set speed. If automatic deceleration/acceleration is not appropri-
ate, adjust the vehicle speed, as well as the distance between your vehicle and vehi-
cles ahead by applying the brakes etc.
■Cautions regarding the driving assist systems
Observe the following precautions. 
Failure to do so may cause an accident resulting in death or serious injury.
●Assisting the driver to measure following distance 
The dynamic radar cruise control is only in tended to help the driver in determin-
ing the following distance between the driver’s own vehicle and a designated
vehicle traveling ahead. It is not a mechanism that allows careless or inattentive
driving, and it is not a system that can assist the driver in low-visibility conditions. It
is still necessary for driver to pay clos e attention to the vehicle’s surroundings.

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2-4. Using other driving systems
2
When driving
CAUTION
●Assisting the driver to judge proper following distance 
The dynamic radar cruise control determ ines whether the following distance
between the driver’s own vehicle and a designated vehicle travelling ahead is
appropriate or not. It is not capable of making any other type of judgement.
Therefore, it is absolutely necessary for the driver to remain vigilant and to deter-
mine whether or not there is a possibil ity of danger in any given situation.
●Assisting the driver to operate the vehicle 
The dynamic radar cruise control has no capability to prevent or avoid a collision
with a vehicle travelling ahead. Therefore, if there is ever any danger, the driver
must take immediate and direct control of the vehicle and act appropriately in
order to ensure the safety of all involved.
■To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON-OFF” button when not in use.
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise contro l in any of the following situations.
Doing so may result in inappropriate sp eed control and could cause an accident
resulting in death or serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered with rain, ice and snow
●On steep downhills, or where there are sudden changes between sharp up and
down gradients. 
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, sn ow, sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in
front of you. As the sensor may not be able to correctly detect these types of vehi-
cles, the approach warning (P. 210) will not be activated, and a fatal or serious
accident may result.

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2-4. Using other driving systems
CAUTION
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane
■Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the foll owing conditions as the radar sensor may
not be able to correctly detect vehicles ahead, and a fatal or serious accident may
result:
●When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor
●When your vehicle is pointing upwards (c aused by a heavy load in the trunk etc.)
●When the road curves or when the lanes are narrow
●When steering wheel operation or your position in the lane is unstable
●When the vehicle ahead of you decelerates suddenly
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function correctly and could result in an accident.
●Keep the sensor and front grille cover clean at all times. 
Clean the sensor and front grille cover with a soft cloth so you do not mark or
damage them.
●Do not subject the sensor or surrounding area to a strong impact. 
If the sensor moves even slightly off position, the system may malfunction. If the
sensor or surrounding area is subject to a strong impact, always have the area
inspected and adjusted by a Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding
area.
●Do not modify or paint the sensor and grille cover.
●Do not replace them with non-genuine parts.