This is a common problem with the A320 series MMRs, kept us busy for a few nights!
Essentially; "The MMR expects to be connected to the GPS network for at least 3 minutes every 512 weeks (approx 9 years) to update the internally stored initialisation date. Therefore, if the difference between the initialisation date and the date provided by the GPS satellites is greater than 512 weeks, the MMR believes itself to have been powered down for longer than is acceptable and the GPS-week-rollover algorithm, which is not equipped for such an event, calculates a date in error"
The "connected to the GPS network" cannot be done on-wing.
Depending on your MMR manufacturer, there are two TFUs from Airbus;
Thales MMR: 34.36.31.009
Rockwell Collins MMR: 34.36.33.001.
With the Thales MMR there is a 'quick fix' that resets the GPS date and fixes the issue, by taking a 'Healthy' MMR from another aircraft (instructions in the TFU).
Last edited by T.R Haychemu; 17th Sep 2012 at 12:43.