DISC 5448431 - Caterpillar

Low Accuracy (GPS)
The GPS receiver is generating positions with errors that exceed the current "GPS Error Limit" set in the AccuGrade System.Probable Causes
Power was cycled to the GPS receiver.
Poor satellite geometry due to the position of the GPS satellites or from physical obstructions
Poor radio coverage
Radio receiving corrections from other base stations
The machine is a long distance from the base station
Fault with GPS receiver
Incorrect "GPS Error Limit" set in the AccuGrade System (consult your supervisor)
Insufficient satellitesIsolating The Problem
Confirm that the power to the GPS receiver is normal and that the connectors are secure.
Ensure that the antenna cables are not damaged and that all connectors are secure with no pins that are bent or broken.Refer to Testing and Adjusting, "Electrical Connector - Inspect"
Check the "Sky Plot" dialog in order to view information regarding satellites. Refer to Troubleshooting, "Diagnostic Capabilities".
Check the "GPS Diagnostics" information. Refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Operational Problems" for details on running receiver diagnostics. Verify the antenna values for "Satellites Used", "PDOP" and "GPS error". For accurate GPS positions to be generated you need 5 or more satellites and the "PDOP" less than 7. As the "PDOP" decreases and the number of "L1" and "L2" satellites increase the GPS error will decrease.
Ensure that the GPS receiver is not obstructed by buildings, trees, or other objects that would impair the line of sight for the GPS receiver.
Verify that the "Integrity" is over 85 percent on the "Radio Data Link" screen. Intermittent corrections can result in increased GPS position error.
Confirm that the "GPS Error Limit" is set at the correct value. If the type of work you are performing permits, you can adjust the "GPS Error Limit" to be greater than the current "GPS position error" as seen in the diagnostics.Note: Always consult the supervisor before you change the "GPS Error Limit".V. Low Accuracy (GPS)
The GPS receiver is tracking satellites and sending the position data to the display in an appropriate format, but the receiver is generating an autonomous GPS position solution.Probable Causes
Base station GPS receiver configuration, power, or cables
Base station radio configuration, power, or cables
Machine GPS receiver configuration
Machine radio configuration, power, or cables
Fault with GPS receiver
Jamming of the radio, this may be caused by close proximity to a powerful transmitter such as a radio, microwave, or a cell phone tower
Receiving corrections from another base and radio networkIsolating The Problem
Unplug your base radio and see if your machine radio will synchronize. If the machine radio does synchronize, there is a duplicate data radio network causing interference.
Change your radio network for all radios on the site.
Check the GPS status of any other machines on the site. If these machines also show the "V. Low Accuracy" message, start troubleshooting the base station.
Verify that the machine radio has power. Refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Machine Radio" for more information on the data radio diagnostics.
Verify that the machine radio is synchronized to your network (orange and green lights illuminated). If the radio is not synchronized, use the "Machine