Updating the various databases is one of the more frustrating aspects of the G1000. The procedure is buried in Appendix B of the Garmin G1000 Pilot Guide and has to be followed precisely or Red X's appear on the CAS and the plane is AOG. It is also equally annoying that a $3M jet can be AOG because of a $5 SD that Garmin does not document how to backup onto another $5 SD card. Might as well use 5 1/4" floppy drives.

In any case, here is a simplified version of the procedure:

1. Pull all three cards lower SD cards from the screens, labeling them if not already done. Note that these are the Garmin cards - generic SD cards will not work.
2. Use Jeppesen JSUM to write Nav Data to generic SD card- this can be any SD card.
3. Use Jeppesen JSUM to write Charts to MFD lower card- this card must be an official Garmin SD card.
4. Use Fly.Garmin.com to write Obstacle and SafeTaxi to MFD card (both updates can be done on same session by enabling "Advanced Installation Options" on "Update Device" page, then checking "Install" for all - this will be the standard procedure in a future version of the G1000 software. This operation is concerned "beta" for now, yet has worked every time so far).
5. Repeat step 4 for each of the dedicated Garmin SD card removed from the PFDs.
6. Insert all three lower cards into screens.
7. Insert SD with Nav Data in top slot of PFD 1.
8. Pull the CBs for the MFD and PFD2, remembering there are two for each screen, one on each side of the cockpit.
9. Power up airplane and avionics, select "Yes" when prompted to update NavData on PFD1.
10. Once PFD Nav Data write is complete, move Nav Data card to MFD upper slot (temporarily removing diagnostics SD card until this step is done), then push in both MFD CBs, select "Yes".
11. Once MFD Nav Data write is complete, move Nav Data card to PFD2 upper slot (and replace diagnostics SD card in MFD upper slot), then push in both PFD2 CBs, select "Yes".
12. Once PFD2 Nav Data write is complete, remove Nav Data SD card, and store until next cycle.
13. Verify DB status in AUX chapter of MFD, ensure CAS box is not covered with red "X", which signifies a DB mismatch. DB mismatches can occur because of expiration date and coverage area. If the database cycle is correct, but Red X's still appear on the CAS, verify that the coverage area of all three devices are precisely the same.

Note that Garmin allows multiple writes of the same database on multiple Garmin SD cards. The Garmin web site does not keep track. Jeppesen allows only a fixed number of writes. If a mistake is made and the database must be re-written, then a call must be placed to Jeppesen Tech Support to reset the download / programming counter in JSUM.