AvMap GeoPilot II - Manual (Page 76)

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15.3 TroUbleShooTInG
The following is a brief guide to some of the problems you may experience while using the Geopilot
II with common solutions.
15.3.1 Power
no Power — The power connections are loose or not fully engaged. Make sure all Power Cable
connections are secure. Make sure the power supply is operating properly. Check the fuse located
at the end of the cigarette plug. (To open unscrew the middle circle at the tip of the adaptor.)
15.3.2 GPS fix
Position fix doesn’t change — The signal from one or more satellites has been lost; the positioning
information displayed is the most recent available.
Position fixes vary a lot — GPS accuracy is affected by several variables, the most prevalent of
which are the geometric quality of the fix. Therefore, the specified accuracy of 15 Meters RMS
in 2D is statistical, not absolute and assumes the absence of Selective Availability which was
discontinued in April 2000.
The Geopilot II is not obtaining position fixes — If the Geopilot II is using an internal GPS
Receiver, proceed to the GPS status screen:
>‘MENU’ 1 sec. + “GPS PAGE” + ‘ENT’
Review the number of satellites in use. If zero, check that the antenna has a clear view of the
sky and that the connections have been made properly. If less than four satellites are in use, the
GPS receiver may have difficulty receiving a fix. Try repositioning the antenna. A GPS fix requires
a minimum of three satellites and a poor Signal Quality on one or more satellites may preclude
receiving a position fix.
Verify the user setting for Fix Source is listed as Internal GPS:
> ‘MENU’ 1 sec. + “SYSTEM SETUP” + ‘ENT’ + “FIX SETUP” + ‘ENT’ + “FIX SOURCE”
+ ‘ENT’ + “INTERNAL GPS” + ‘ENT’
If the Geopilot II is using an External GPS receiver, proceed to Fix functions screen:
> ‘MENU’ 1 sec. + “SYSTEM SETUP” + ‘ENT’ + “FIX SETUP” + ‘ENT’
Verify that the Fix Source is listed properly (External NMEA) as indicated in the System Setup section
(see Chapter 14) and that the Baud Rate is set correctly for your GPS receiver (the Geopilot II
requires 9600- Baud Rate). Verify that the data cable connections are proper.
external device is not responding — The data port is not turned on or is not outputting messages
in the correct format. Refer to the external device’s user guide to determine the correct message
format. Check the Installation Settings menu and make any necessary changes. The Geopilot II
may not be properly connected to the external device. Check all connections to be sure they are
correctly made and secure.
navigate feature does not work — Blanks are displayed in the navigation data fields until a GPS
fix has been obtained; this usually occurs within a few Minutes. Also a Flight Plan must be active
to display values for navigation-related information (such as Cross Track Error) and you must be
travelling at least 2 Knots to display values for velocity-related information (such as GS). Activate
a Flight Plan and/or increase your speed.
fluctuations in positioning and navigation data — Small fluctuations in positioning and velocity-
related navigation is normal.
15.3.3 When nothing else Works
The list above should allow you to solve most of the operating problems you are likely to encounter.