2004 Lincoln Navigator Owner Guide 4th Printing - Page 251

Driving The system detects obstacles up to a maximum range of 20 feet (six meters at speeds above 2 mph [3 km/h]) or 10 feet (3 meters at speeds below 2 mph [3 km/h) behind 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 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. The extended rear park assist is automatically enabled when the gear selector is placed in R (Reverse) and the ignition is ON. A park assist control in the message center allows the driver to disable the extended rear park aid only when the ignition is ON, and the gear selector is in R (Reverse). Always keep the sensors (located on the rear bumper/fascia) free from snow, ice and large accumulations of dirt (do not clean the sensors with sharp objects). These elements may cause the system to operate inaccurately. If the vehicle sustains damage to the rear bumper/fascia, leaving it misaligned or bent, the sensing zone may be altered causing inaccurate measurement of obstacles or false alarms. 251 2004 Navigator (nav) Owners Guide (post-2002-fmt) USA English (fus)