Lincoln 2004 Town Car Owner's Manual page 198

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 objects to avoid damaging the vehicle.
The system may not detect smaller objects, particularly those close to
the ground.
Certain add-on devices such as large trailer hitches, bike or
surfboard racks and any device that may block the normal
detection zone of the extended rear park aid system may create false
beeps.
The system will assist the driver in detecting certain objects while the
vehicle slowly moves in reverse at speeds less than 6 mph (10 km/h).
The system is not effective at speeds greater than 6 mph (10 km/h) and
may not detect certain angular or moving objects.
The system detects obstacles within approximately 16 feet (five meters),
at speeds above 2 mph [3 km/h]) behind the rear bumper with a
decreased coverage area at the outer corners of the bumper. If vehicle
speed is below 2 mph (3 km/h), the system detects obstacles within
approximately 10 feet (three meters) behind the rear bumper with a
decreased coverage area at the outer corners of the bumper. In the
figure, the smaller objects behind the vehicle represent the near-vehicle
and bumper corner coverage area of the park aid system and the large
object represents the extended coverage area. As you move closer to the
obstacle, the rate of the tone increases. When the distance to the
obstacle is less than 18 inches (45.0 cm), the tone will sound
continuously. If the system detects an object that is approaching the
vehicle at such as rate that rapid braking is required, a very high rate
tone will sound. If this tone is heard while reversing, the driver is
advised to slow down immediately until the tone either changes to a
slower rate or stops. While receiving a warning the radio volume will be
reduced to a predetermined level. After the warning goes away, the radio
will return to the previous volume. The radio volume may be overridden
using the radio volume control.
REVIEW COPY
2004 Town Car (tow), Owners Guide (post-2002-fmt) (own2002),
Market: USA_English (fus)
Driving
197