Lexus 2003 LS Owner's Manual page 276

STARTING AND DRIVING
5 Resuming the preset speed
If the preset speed has been cancelled, when you push the
lever up in the "RES/ACC" direction while "RADAR READY"
shows up on the multi–information display and at a vehicle
speed of about more than 40 km/h (25 mph), the speed set
prior to cancellation will be restored.
During follow–up cruising, if there are no vehicles running
ahead because they have changed lanes, your vehicle will
accelerate gradually up to the preset speed. At this time,
pushing the control lever upward in the "RES/ACC" direction
will quickly speed up your vehicle in vehicle–to–vehicle
distance control mode.
CAUTION
A Deceleration
cruising
warning do not operate when the vehicle ahead is at
a stop or driving very slowly
A While vehicle–to–vehicle distance control (follow–up
cruising) is on, acceleration and deceleration are
automatically performed in proportion to the speed
of the vehicle ahead detected. However, if the vehicle
ahead of you decelerates abruptly or if another
vehicle cuts in ahead of you, your vehicle may collide
with the vehicle ahead unless you manually depress
the brake pedal to slow down your vehicle. If you
need to accelerate because the vehicle ahead or you
changes lanes, then depress the acceleration pedal.
262
function and approach
A Depending on the road configuration (curved roads,
left and right continuous curved roads, driving at the
start or end of the curve, narrow driving lanes due to
road construction) or your vehicle condition
(steering wheel maneuvering, position in the lane or
unstable driving because of an accident or
breakdown), vehicles in other lanes or surrounding
objects will be detected, resulting in a control failure
or the activated approach warning. This may also
result in a very close distance between vehicles due
to a failure to detect the vehicle ahead. Maneuvering
the steering wheel in response to a violent lateral
wind will cause similar conditions.