Like other members, I've had problems with my 04 tls navigation system. I disconnected the battery to do a audio system install and keep getting the "please check your disc" error afterwards. I have three questions regarding this problem

1. What contents of the navi does the dvd disc control?
I've started the car without the dvd disc and only get the "please check your disc" message.
I've started the car with the dvd disc and it say now downloading for 4 seconds then give the check disc error.

2. Does the fact that it tries to download with the navi disc installed mean the dvd rom is working and it's a bad disc?

3. Has any members had this problem fixed by using a more updated disc?