Why is the Sat Nav not working?

Bmw 328ci e46 radio with built in sat nav stuck in a high volume?

• The radio on my bmw 328ci e46 with built in sat nav stuck in a high volume with side buttons, volume control/mute button, CD player and changer stop working. This happened after I've changed a battery. I can't knock off the radio at all or even change the channel! The navigation works.TV works but with the sound still coming from a radio The only way to mute the thing is to take off the fuse wich turns off the whole screen. This drives me really mad. Any ideas?

• Answer:

  As I have already stated try doing an overnight battery reset by removing the negative battery terminal and hope for the best when you re-attach the terminal. Other than this, re-programming/coding of the audio system is the next step along with checking for fault codes with a BMW GT1. Since you failed to mention the year of the car (there are so many E46's) I can not specifically tell you if a GT1 with software version 44 or an SSS/Istap variant can do coding for your car. After doing a battery reset and coding, with the radio still stuck, then parts replacement may be needed based on whatever fault code is in store (along with the proper diagnostic measures).