Here is a procedure I copied from another post of which someone was nice enough to share. I'm sure he will speak up if he wants his name advertized..... I'll let him have the pleasure. Keep in mind, I'm sure this is not mean't for the normal public and I would recommend not changing anything you are not comfortable with. Viewing is one thing, but monkeying around may be at your own risk. I found an error with my Nav and I'm sure it was because I was playing around with trying to get the disk out... I did so, tried to copy it unsuccessfully several times because even though I burnt the disks just fine, it wouldn't read them. I was able to clear the error code and did a recheck and now it checks out ok. I was also able to find the elusive audio level indicators we have been looking for for so long and although you can test and even record yourself and play it back, I didn't find a sensitivity setting per se to adjust. I also notice a cool procedure to back up all your nav settings, and restore them back if ever needed, but you need some kinda "tool".. if you don't have it, it gives you an error saying... hey you don't have the tool! There is alot to look at and I'm not sure what all I'm seeing and what good someone can do with it. You can see gps figures, coordinates, settings etc and it looks like if you tried hard enough, you could probrably screw something up without too much trouble.. so I didn't tinker with any of that. You can also look at battery voltages as well as many other items. Here are the instructions on how to access the screen: As follows: Power up (if not already up),Push display and hold, turn headlights on and off completely, three times. A display screen will then come up, hit display (on the screen), hit menu, According to the person who shared this info, You can also drive with the screen in this mode, you will not have access to the other info. In order to get rid of this display you have to power down. If needed, this also works in Accessory mode too.