Cadillac 2008 Escalade Navigation System Owner's Manual page 52

Global Positioning System (GPS)
The navigation system determines the position of your
vehicle by using satellite signals, various vehicle signals,
and map data.
At times, other interferences such as the satellite
condition, road configuration, the condition of the vehicle
and/or other circumstances can interfere with the
navigation system's ability to determine the accurate
position of the vehicle.
The GPS shows the current position of your vehicle
using signals sent by the GPS Satellites of the United
States Department of Defense. When your vehicle is not
receiving signals from the satellites, a symbol will
appear on the map screen. Refer to Symbols on
page 2-7.
This system may not be available or interferences may
occur if any of the following are true:
•
Signals are obstructed by tall buildings, trees, large
trucks, or a tunnel.
•
Objects are located on the rear shelf.
•
Satellites are being repaired or improved.
•
After-market glass tinting has been applied to the
vehicle's rear windshield.
2-38
Notice: Do not apply after-market glass tinting to
the vehicle's windows. Glass tinting will interfere
with the system's ability to receive GPS signals and
cause the system to malfunction. You might have
to replace the window to correct the problem.
This would not be covered by your warranty.
For more information if you are experiencing a problem,
see If the System Needs Service on page 2-40 and
Problems with Route Guidance on page 2-39.
Vehicle Positioning
At times, the position of the vehicle on the map may be
inaccurate due to one or more of the following
reasons:
•
The road system has changed.
•
The vehicle is driving on slippery road surfaces
such as in sand, gravel, and/or snow.
•
The vehicle is traveling on winding roads.
•
The vehicle is on a long straight road.
•
The vehicle is approaching a tall building or a large
vehicle.
•
The surface streets run parallel to a freeway.
•
The vehicle has just been transferred by a vehicle
carrier or a ferry.