Service Mode: GPS
Selecting GPS from the service mode menu displays the version information menu for the GPS receiver integrated into the navigation computer.
Selecting < Return returns the system to the service mode menu. Selecting Function brings up a functions menu for the GPS. From the functions menu, the GPS status and tracking information can be checked.
GPS Status Check
Selecting GPS Status on the GPS functions menu displays the status menu of the GPS system. The status menu shows the current position in latitude and longitude, the approximate altitude and the time and date (always displayed in Greenwich Mean Time (GMT)).
The ground speed and heading can be checked when the vehicle is in motion. The indicated ground speed should be the actual vehicle speed in m/s and the heading should be the actual direction of travel in degrees.
The Rec Stat/Pos Src element is used to check that the GPS system is functioning correctly. The Rec Stat window displays one of the following:
- POS - The system has a current position fix. This indicates that the GPS system is working normally. The Pos Src window indicates the type of position fix (2D or 3D) and the number of satellites being received.
- TRACK
- The system is tracking a number of satellites. This indicates that the system is working normally but does not yet have enough information to determine the position of the vehicle. Check that there is nothing obstructing the GPS antenna's 'view' of the sky.NOTE: When exposed to satellites for the first time, the GPS system can take up to 15 minutes to determine the position of the vehicle.
- COMERR - There is a communication error between the GPS receiver and the navigation computer
- SEARCH - The system is searching for satellites. If this is displayed it may mean there is a failure in the GPS system. First check that there is nothing obstructing the GPS antenna's 'view' of the sky. Check the connections between the GPS antenna and the navigation computer.
GPS Tracking Information
Selecting the GPS Tracking Information from the GPS functions menu displays the satellite being received on each channel together with a signal level. The menu also displays the number of satellites that are currently being received and the Almanac status.