I can't get into the map on my pioneer avic d3

The AVIC D3 is not pioneers best. The navigation side of the unit is wearing out. The slider slot in the dvd and other moving parts are wearing down fractionally and that is all it takes for the unit to no longer read the high density map data discs. The map disc is a dual layer 8.5gb disc and it is just about max out. (The disc must be in the unit for the navigation to work.) This is a lot of information and the unit must be able to read every bit of data on the disc or it will error out. All it takes is the fractional wear to mess up the tracking of the laser over the disc and cause problems reading the data on the disc. When the unit spins and spins, it is working hard to read something on the disc and will eventually error out if it can't. Also a fingerprint or tiny spot on the disc will prevent the unit from reading the disc. (Clean with a drop of water and soft cotton cloth even if it looks clean.) The data is information or instructions telling the unit what to do, and if it misses any information it will go crazy and error out. This is very different from music or video/movies that just play and if a spot is on the disc it will just be a fuzzy picture or static from that spot. If you have a disc your system likes, take care of it. I say likes because every disc has fractional differences in data location on the disc. (This is tolerance) That fractional difference could make or break the ability of your unit to read the map disc. So one possible fix is trying different disc to see if your unit will like one of them. Still eventually this also will die. These units are beyond their life cycle and the dvd drive is operating on borrowed time. I hope this helps.