Chevrolet 2011 Corvette Navigation System Navigation Manual page 82

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 of the vehicle.
Satellites are being repaired or
improved.
After-market glass tinting has
been applied to the vehicle's
rear windshield.
For more information if the GPS
is not functioning properly, see
and
.
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.
The current position calibration
is set incorrectly.
The vehicle is traveling at high
speed.
The vehicle changes directions
more than once, or when the
vehicle is turning on a turn table
in a parking lot.
The vehicle is entering and/or
exiting a parking lot, garage or a
lot with a roof.
The GPS signal is not received.
A roof carrier is installed on your
vehicle.