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Blog Editor Note: We thought GPS week rollover problems were all done with…

Passing this along as part of our public education and “protecting GPS/GNSS users” missions.


Published 14 December 2021

Summary of issue

The Maritime & Coastguard Agency would like to make operators aware that products with Furuno Global Positioning System (GPS) chips for position or UTC (Coordinated Universal Time), may produce an error on January 2nd, 2022. The problem affects products listed in Annex 1 and includes navigation and communication equipment.

Stand-alone Furuno GPS receivers and equipment using Furuno GPS chips, could produce data that is 19.7 years in the past, therefore generating errors in both the GPS position and date (19th May 2002).

The 19.7 year date error may result in instability in positioning, causing position errors, including failure of GPS position acquisition, etc.

Actions to take

  1. Cold-start the equipment through the operating menu. The procedure for each affected equipment is stated in Annex 2. Please note, although you should reacquire the GPS position, date information cannot be restored by cold-starting;
  2. If GPS position is not reacquired after cold-starting, the problem may stem from failure of the equipment itself not from GPS week number rollover. If this is the case, contact a nearby Furuno authorised marine electronics dealer;
  3. To restore the correct date for the models with an available remedy, contact a nearby Furuno authorised marine electronics dealer to replace the GPS receiver inside the device or update the software/firmware (both for a fee);
  4. If there is no available remedy for your model it is likely that the equipment will need replacing entirely. If this is the case, contact a nearby marine electronics specialist.

Owners are responsible for the correct operation and maintenance and should contact Furuno for advice.

Further information

See Furuno UK website for the latest information: