Lexus 2004 LS430 Owner's Manual page 354

STARTING AND DRIVING
D 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 serious injury or death. (In this
case, automatic braking will not work.) If there is a
vehicle detected ahead, the delay in deceleration
timing could cause serious injury or death.
D When the warning tone sounds frequently (because
acceleration or deceleration was repeated or
sufficient vehicle-to-vehicle
maintained), an appropriate vehicle speed cannot be
attained, resulting in serious injury or death.
D 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 serious injury or death.
334
Dynamic laser cruise control—
Certain conditions make vehicle detection difficult or
impossible.
D As this system operates by detecting primarily the
reflectors of the vehicle ahead, the distance cannot
be accurately detected in the following cases,
resulting in improper vehicle-to-vehicle distance.
distance was not
D The vehicle ahead has higher ground clearance,
which means that the placement of the reflectors
is in a higher position.
D The rear section of the vehicle ahead is extremely
dirty.
D The vehicle ahead or other vehicles around you
are flinging up water or snow.
D Excessive exhaust gas (black smoke) is coming
from the vehicle ahead or other vehicles around
you, obscuring your front view.
D Protective film is attached to the reflectors on the
vehicle ahead, or reflectors are not installed on the
vehicle ahead or are damaged.
D Heavy luggage which is loaded in your trunk or on
top of your rear seats is raising up the nose of your
vehicle.
CAUTION