WARNING â€“ These instructions are provided as is and what worked for me. As others have warned, and so do I: USE AT YOUR OWN RISK! YOU MUST HAVE THE ORIGINAL or COPY OF THE ORIGINAL AVIC-D3 NAVIGATION/MAP DISC(S) TO PERFORM THE DIRECTIONS LISTED IN THIS POST. With that said, I have just had to fix my GPS Navi software on my AVIC-3D, yet again. I have owned the Pioneer AVIC-D3 for 10 years since it was first released. Each time I have had to replace the battery in my vehicle and a number of times for unknown reasons, the GPS Navi software/programming has â€˜crashed.â€™ I know the disconnection of the power is the obvious reason when the batteries were replaced, yet I still have had a few â€˜unknownâ€™ times when the GPS Navi crashed. The only other thing I could add is I have satellite radio and have noticed various times when 'Updates' happened while listening. I presumed these were updates for the satellite radio module. I canâ€™t say for sure the loss of GPS Navi did or did not have anything to do with these updates. I do know that one time I lost the GPS Navi the day after I saw the satellite radio module updating. Iâ€™m not saying that this is or is not a cause for these Insert appropriate disc issues, but I suspect it could be 'a' cause just like the battery/power disconnect. Whatever it is, the GPS Navi software becomes corrupted and makes it necessary to be reloaded. THE PROBLEM Although, the GPS Navi programming would be lost, all other functions (AM/FM radio, satellite radio, CD, and DVD) remained working. For me, it has only been the GPS Map Navigator, splash screen, and background screens which quit functioning. The irritating part was I would have to manually reset all of the other settings. This included the time, volume settings, colors, splash screen, etc. This is because the main settings to the unit are controlled through the GPS Navi screens. Prior to the Insert appropriate disc message, to solve the problem all I would have to do, while in NAV mode, was insert one of the original map discs and the unit would reload the GPS Navi software automatically. Then I would manually change the settings. Then, BOOM, one day I started getting the Insert appropriate disc message and the map discs were no longer recognized by the unit. The discs were not damaged and I was able to make backup copies with a standard DVD disc copier program. The copies did not work either. Thru investigation on the web, I concluded the problem was not with the â€˜discs.â€™ Too many people were having the same problem, yet none of the different solutions on the web worked. At least not for me. As I stated above, the other functions of the unit remained working. All my AVH presets, except for the light and screen colors were not lost either. For me, it has only been the GPS Navi maps and associated functions which quit functioning. HERE IS HOW I OVERCAME THE PROBLEMS: Note - You must have an AVIC-D3 remote control to enter and modify the unit thru the TESTMODE MENU. I have a CD-R55 remote. There are 2 side switches on this remote. On one side is a small AVH/AB switch. This switch needs to be set to AVH. On the other side is a DVD/TV/AVH switch. This switch needs to be set to DVD. As stated in UnSoundBaxtaâ€™s post above: On the front of the AVIC-D3 console, hold down the Eject button and using a paperclip press the hard reset button immediately to the right of the Eject button. Keep holding the Eject button until the â€œPlease press the [RESET] buttonâ€ message is displayed. Next, enter 81837208 on the keypad of the remote. If the side switches of the remote are set correctly, you will hear a beep every time you enter a number. When you successfully enter the number code a password screen will appear for a couple seconds and then will automatically change to the first TESTMODE MENU screen. Note â€“ You should NOT have to enter a password. As UnSoundBaxta also stated, the controls on the remote to navigate the TESTMODE MENU(S) are: 2 = up; 4 = left; 5 = enter/select; 6 = right; 7 = Navi; 8 = down; and C = BACK button. NOW THIS IS WHERE THE DIRECTIONS ARE DIFFERENT On the first TESTMODE MENU, press the down (8) button twice to highlight 3. Format FLASH drive then press Enter (5) button to select. This clears the AVIC-D3â€™s corrupted navigational software. Wait for the unit to finish formatting the drive. Next, press the right (6) button and go to the second TESTMODE MENU. Press the down (8) button five times to highlight 6. Program forced write. Press the Enter (5) button. The System program will be highlighted. Press the Enter (5) button again. Press the down (8) button to highlight 2. DVD/CD-ROM and press the NAVI (7) button. Wait for the software to be 100% uploaded. Turn your vehicle key to the off position. Wait 5 seconds and turn the key back on. The AVIC-D3 should recognize the already inserted original map disc and re-install the GPS Navi program to itâ€™s original state. Answer the startup questions thru the touch screen and voila the GPS Navigational functions/map are operational again. Some additional notes: The AVIC-D3 requires the original GPS Navi software to be functional before update software/maps can be installed. When the unit â€˜crashesâ€™ like this, I have found you have to install the original map disc software before you can install the subsequent updates. I did try to force the maps into memory like UnSoundBaxta stated in his post. The unit indicated it had 100% upload, yet I still have to put the map DVD into the ROM unit for the GPS maps to function properly. I believe when this model was made, it was not cost effective and the memory chips too large to have 7+ gigabytes of memory on board to hold all data from the map disc. I believe the forcing of the maps function in the TESTMODE MENU screens is to load the 'directory' of the DVD map disc into memory and not the complete data on the DVD disc. Finally, if you havenâ€™t ever loaded your own background/splash screen pictures onto the unit, you should try it. There are 3 separate screens you can customize. Itâ€™s neat to have a picture of your choosing as the splash screen that comes up every time you start the unit and as backgrounds on the player and map screens. Just burn JPG files of your choosing onto a CD. Then use the upload functions in the GPS Navi System menus. I hope you find this post helpful.