FORD 1999 Windstar - Manual (Page 68)

This system is not designed to prevent contact with small or
moving objects. The system is designed to provide a warning to
assist the driver in detecting large stationary objects to avoid damaging
the vehicle. The system may not detect smaller objects, particularly
those close to the ground.
The RSS will assist the driver in detecting certain objects while the
vehicle slowly moves in reverse at speeds less than 6 km/h (4 mph). The
RSS is not effective at speeds greater than 6 km/h (4 mph) and may not
detect certain angular or moving objects. The weather may also affect
the function of RSS. RSS may have reduced performance, or be activated
in inclement weather.
The reverse sensing system detects
obstacles within approximately
1.8 meters (5.9 ft.) of the rear
bumper with a decreased coverage
area at the outer corners of the
bumper, (refer to the figures for
approximate zone coverage areas).
As you move closer to the obstacle,
the rate of the tone increases. When
the distance to the obstacle is less
than 25.0 cm (10 in.), the tone will
sound continuously. If the system
detects a stationary or receding
object further than 25.0 cm (10 in.)
from the side of the vehicle, the
tone will sound for only 3 seconds.
Once the system detects an object
approaching, the tone will sound
again.
Controls and features
68