Recurrent Bluetooth problem when I connect to Thunderbolt display

I also have this problem running on a Macbook Pro Retina Late 2015.

Bluetooth preferences shows:

You can't open the "Bluetooth" preferences pane because it is not available to you at this time.

To see this preferences pane, you may need to connect a device to your computer.

And Bluetooth shows up as "Not Available":

I ran Apple Diagnostic Tool and it told me that I had a defective bluetooth module (hardware issue) and instructed me to contact Apple for a replacement. And so I did.

But the second Macbook I got from them also had this issue. Resetting the SMC is just a temporary workaround.

I'm suspecting it has something to do with the thunderbolt ports. They seems to cause some bluetooth failure when connected/disconnected..

Also, the problem is present in Bootcamp (Windows 10) installation as well. The Bluetooth module shows up as installed but with wrong drivers in "Device Manager".

Trust me, I would've posted the answer if I had it. Have you reported this to Apple Support?

I have the same problem with the same specs as you; on OS X El Capitan, version 10.11.5, on a MacBook Pro Retina Early 2015.

I realise if I start the my MacBook Pro without connecting to the Thunderbolt display first, it will not have the bluetooth problem. But if I start the MacBook Pro with the Thunderbolt display connected, then the bluetooth failure would appear the moment it start up. Also if this happens, if I shut down and start up again with the Thunderbolt display disconnected, then the bluetooth is back to normal without the need to do a SMC reset.

Previously I did the PRAM and SMC reset but the bluetooth error persists.

I am also still looking for a permanent solution better than disconnecting the Thunderbolt display initially. Anyone have any idea?

Anyone discover a solution to this? I just replaced a late-2013 15" rMBP with a brand new mid-2015 15" rMBP. The 2013 had no problems connected to the TBD, but like all of you, the 2015 has bluetooth when disconnected, but looses bluetooth when started up connected to the TBD. Very frustrating! Wondering if the new Sierra beta fixes the issue? Then again, the 2013 is being sent with my son to college...maybe I should send the TBD too and replace it with a new monitor and Thunderbolt dock. It's just the convenience of the TBD and all it's ports. And money. Sigh.

Answering my own question, it does appear that this issue is fixed under Sierra. I should have checked beforehand, because I did have beta 2 on an external drive. With the 2015 15" rMBP connected to the Thunderbolt display running under 10.11.6, I had no bluetooth. I booted into the Sierra beta 2 and had bluetooth. I then updated to beta 3 (while still connected to the TBD) and after the restart, still had bluetooth. So it appears the solution is to wait, or run the beta.

Mid 2015 15-inch Retina MacBook Pro here running Sierra 10.12.5 and I have that exact same issue.

Very annoying.