Present Location Display Error; Error Due To Having Changed A Tire; Correcting The Map Matching Vehicle Position Sensor - Eclipse AVN2454 Owner's Manual

Helpful tips
3. Accuracy and error

Present location display error

In order to find the exact position of the present location, this device uses compiled data
from the GPS satellite, vehicle speed sensor and vibration gyro sensor. Because each of
these contains a margin of error, the present location indicated may not coincide with your
actual positioning.
If the indication is different from the actual positioning, the present location displayed can
be corrected. Park the vehicle in a safe place first before proceeding.

Error due to having changed a tire

The device calculates the distance traveled by the vehicle using a speed sensor (in
proportion to the tire rotation). The following situations would result in a significant error that
may render proper present location positioning impossible.
•When using a sub-standard tire
•When driving on a snow covered, gravel road or any slippery road
•When the tire air pressure is incorrect
•When using new tires (the distance correction coefficient setting can be changed and
adjusted)

Correcting the map matching vehicle position sensor

Map matching is a system that compares present location positioning data from the GPS
and other sources with information concerning all the roads driven on until now in order to
correct the present location onto the most appropriate road. This device corrects the
present location data compiled from a combination of independent navigation and satellite
navigation and matches it with the shape of the road.
However, there may be instances when the present location error cannot be avoided and
the position indicated on the map does not coincide with your actual positioning even after a
correction using map matching.
Also, driving along a road whose actual shape differs from the map data may result in a
vehicle position mark misalignment.
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