I have the same issue with greyed-out BT settings as many others. I have tried a lot of things like flashing different firmware versions of the BT module, erasing its stored data and verifying that the module itself is working fine via supertestmode. My final conclusion is that not the module is faulty but the pioneer software that controls it. I am pretty sure that it could be fixed by replacing the files inside the folder USER\RW\SETUP\BT with the ones from a working unit.

Does somebody have a backup copy of his unit available and could provide these files (esp. BTUNIT.DAT)? Or would somebody be so kind to copy them via supertestmode?

Just put the attached file in the root of an SD-Card, navigate to \USER\RW\SETUP, mark BT for copy, navigate to \SD and select paste.

TESTMODE.KEY

First make sure that your parking brake is detected as set. Go to Settings / Navi Settings / Connection Status  and make sure it says Parking Brake is On. When Off, some settings and functions are grayed.

4 hours ago, RonS said:

First make sure that your parking brake is detected as set. Go to Settings / Navi Settings / Connection Status  and make sure it says Parking Brake is On. When Off, some settings and functions are grayed.

Thanks Ron, but it is not an issue with the parking brake. As I said, I did a lot of tests including direct access to the parrot module via AT-commands and it is all fine. It is just the communication with the Pioneer BT application software that does not work. Somehow the settings in USER\RW\SETUP\BT\BTUNIT.DAT got messed up. That's why I need this file from a working unit. 

1 hour ago, morus said:

Thanks Ron, but it is not an issue with the parking brake. As I said, I did a lot of tests including direct access to the parrot module via AT-commands and it is all fine. It is just the communication with the Pioneer BT application software that does not work. Somehow the settings in USER\RW\SETUP\BT\BTUNIT.DAT got messed up. That's why I need this file from a working unit. 

On my Z110-BT it is in /USER/SETUP/BT.  Here's mine but I don't know if it will work. Did you try just copy/deleting yours and see it it could be recreated?

BTUNIT.DAT