Toyota Lexusc Owner's Handbook Manual page 488

CAUTION
To avoid accidents, always keep the laser radar sensor
glass clean and never allow it to be covered with icicle
or any substance, so it can detect the vehicle in front.
(See "(k) Laser radar sensor" on page 478.)
STARTING AND DRIVING
CAUTION
Do not rely excessively on dynamic laser cruise control.
Observe the following precautions in order to avoid
serious injury or death:
D Under certain conditions where the vehicle in front
slows drastically, or is stopped, the dynamic laser
cruise control will neither warn you nor decelerate.
You must depress the brake pedal to slow down,
ensuring collision avoidance or that sufficient
vehicle-to-vehicle distance is maintained.
D Do not use dynamic laser cruise control in the
following conditions:
In bad weather (such as rain, fog, snow, sandstorms
or direct sunlight, or when raindrops or snowflakes
get on the laser radar
vehicle-to-vehicle distance will not be measured
accurately.
When using the windshield wipers at high or low
speeds the dynamic laser cruise control turns off.
On roads with heavy traffic or sharp bends, an
appropriate speed cannot be maintained and an
accident may occur.
sensor glass), the
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