Nav will be backlit but never goes to the screen to enter code? Only twice has that screen up and didn't have the code to enter it. Pull the positive off batt to see if that would help. It hasn't. Any input?

 

Try taking the dvd unit out from the trunk and cleaning the interior with alcohol. It's not that hard, there's a DIY around on the forum somewhere if you need help. I would say try a different nav dvd but I don't think that's relevant to your problem, try it any hows. Also you can take it to a dealer and have them diagnose it but i'm pretty sure they're gonna overcharge you. Worst comes to worst you'll most likely gonna have to replace the whole dvd unit in the trunk or have it repaired. I'm having similar problems with mine and none of my research really led me to a solution besides replacing it or sending it in for repair.