Lexus GS430 User Manual page 428

STARTING AND DRIVING
If no vehicle is running ahead of you:
1 Cruising at a fixed speed: If there is no vehicle detected
ahead, your cruising speed is maintained at the preset
speed from about 45 km/h (28 mph) to about 135 km/h (85
mph). The preset speed is displayed in the
multi−information display. For the vehicle speed setting,
see "Setting operation " on page 408.
If a vehicle is detected ahead of you:
2 Deceleration cruising function: If a slower moving
vehicle is detected ahead of you, your vehicle cruising
speed decreases within the range of about 40 km/h (25
mph) to about 135 km/h (85 mph). The multi−information
display shows the preset speed, the detected vehicle
ahead and selected vehicle−to−vehicle distance. If your
vehicle gets closer to the vehicle ahead because of
insufficient automatic deceleration, then the warning tone
warns you to also manually apply brakes.
3 Follow−up cruising function: After deceleration, your
vehicle cruising speed changes in proportion to the speed
of the vehicle ahead to maintain an appropriate distance
from your vehicle to the vehicle ahead.
vehicle−to−vehicle distance can be changed. For details,
see "Changing vehicle−to−vehicle distance setting" on
page 412.
4 Acceleration cruising function: If the vehicle ahead
changes lanes, your vehicle cruising speed will be
gradually increased up to the preset speed, and your
vehicle resumes fixed−speed cruising.
404
Under certain conditions where the vehicle in front
slows drastically, or is stopped, the dynamic radar
cruise control will neither warn you nor decelerate. The
driver must depress the brake pedal to slow down,
ensuring collision
vehicle−to−vehicle distance is maintained.
When vehicle−to−vehicle distance control mode is activated,
you must still be attentive to road and traffic conditions. Should
your vehicle speed decrease below about 40 km/h (25 mph),
the dynamic radar cruise control will shut off, requiring you to
apply the brakes to slow. When a vehicle ahead slows
suddenly, stops or a vehicle cuts in front, the system may slow
your vehicle abruptly, but the automatic braking will cease if the
speed decreases below about 40 km/h (25 mph) requiring the
driver's manual application of brakes.
The
CAUTION
avoidance or that sufficient