An odd thing happened the other day when I disconnected my battery to install my foglights! When I reconnected the battery connection, the navigation system asked for the code. I entered the code, but after about 10 min of trying to obtain signal, it timed out and asked me to disconnect the battery and try again. I remembered last time this happened, I turned of the ignition then turned it back on to enter the code. However, this time I had to get to work so I didn't want to fiddle around with it. After parking for a few hours, I turned on the engine and low and behold, the navigation came on without the code again. I checked the radio because I know I did not enter the code for it earlier, and it too worked! What the heck?

 

It may have not fully reset the system. I think the power needs to be lost to the radio and nav for a certain length of time before it will ask for the code again.

 

the dealer told me that when u disconnect the battery there is still juice in the capacitors but they slowly drain. maybe a few minutes or so. in order to totally drain the system you need to disconnect the battery and touch the positive and negative terminals together. this will drain the capacitors in an instant

 

I just pulled the fuse then re-inserted it and was asked for my code.