Cadillac 2009 Escalade EXT - Manual (Page 304)

Global Positioning System (GPS)
The navigation system determines the position of the
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 the vehicle using
signals sent by the GPS Satellites of the United States
Department of Defense. When the vehicle is not
receiving signals from the satellites, a symbol appears
on the map screen. Refer to Symbols on page 4-16.
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 front dash of the vehicle.
• Satellites are being repaired or improved.
• After-market glass tinting has been applied to the
vehicle’s windshield.
Notice: Do not apply after-market glass tinting to
the vehicle’s windows. Glass tinting interferes
with the system’s ability to receive GPS signals and
causes the system to malfunction. The window
might have to be replaced to correct the problem.
This would not be covered by the warranty.
For more information if the GPS is not functioning
properly, see If the System Needs Service on page 4-56
and Problems with Route Guidance on page 4-55.
Vehicle Positioning
At times, the position of the vehicle on the map may
be inaccurate due to one or more of the following
reasons:
• Road system has changed.
• Vehicle is driving on slippery road surfaces such as
in sand, gravel, and/or snow.
• Vehicle is traveling on winding roads.
• Vehicle is on a long straight road.
• Vehicle is approaching a tall building or a large
vehicle.
• Surface streets run parallel to a freeway.
• Vehicle has just been transferred by a vehicle
carrier or a ferry.
4-54