I haven't come across your particular radio before. You'll need to see if you can find the user manual for your system as I'm thinking there's maybe a separate code for the navigation system too..
If you can get the system to request another code somehow, I'd guess it would be a 5 digit code request, I'd put in this code :- 24531.
Sorry, I'm just guessing here, but I have come across other navigation systems needing two codes..