16-inch MacBook Pro Bluetooth issue

I'm also facing this issue since accidentally connecting an old BT dongle I had inserted into the USB ports of an old monitor that I had to connect to my macbook.

Instant BT failure.

Also, I'm on a 13" MBP from 2019 (the one with the 4 thunderbolt ports from March I think).

However, none of the fixes claimed here have worked for me. I don't know if the issue is my BT dongle (actually, the one that caused the issue in the first place) or if I'm doing something wrong, but nothing has fixed it for me.

Can anyone double-check the dongle?

I used the following BT adapter to fix the issue:

Device vendor ID (VID): 1131 (which is "Integrated System Solution Corp." or "ISSC")

Product ID (PID) = 1004.

The reported Bluetooth standard supported by this dongle is 2.0.

As others have pointed out, do notice however that while bluetooth is back to a working state, System Report still says that the WLCore versions are null, that the Airport Utility is not installed and the Bluetooth Explorer still references the -3903 error..

I've tried reinstalling the last update but the error still persists. Did anyone manage to get rid of the error by reinstalling MacOS? Even if totally wiping the disk is required?

Couple of us are having the same issue, used a USB device with bluetooth attached on a MBP 16 and then the internal bluetooth stops working.

Plug the USB device with bluetooth back in and the devices all work again.

Anyone found a way resolve this ?

I had exactly the same problem (down to every detail) and I think I just found a solution.

I'm also using a CalDigit dock and USB bluetooth stick and I'm on my second MBP 16. The first was replaced under AppleCare after the bluetooth module became apparently dead.

The built-in bluetooth came back to life by running system diagnostics (hold down D during boot). After the subsequent restart, without the USB bluetooth adapter attached, I noticed that bluetooth was seeing some devices in the area but still not connecting to anything. I deleted and re-paired my Magic Mouse 2 and Magic Keyboard 2 - now all is working again.

Thanks for sharing Simon, have tried running the Diagnostics and deleting the bluetooth devices and repeering and it didn't working for me.

For others that are interested I have a support ticket open with Apple and have provided diagnostics and logs to help troubleshoot the issue.

Still running my extra dongle for now, will share what I find !

Same issue here. When I open "About this Mac -> System Report -> Bluetooth", I am seeing "Discoverable: Off" and "Connectable: No" - this seems strange. These turns into "On" and "Yes" when I enable Bluetooth sharing, but it does not resolve the issue. Still no devices could be connected to Bluetooth. Even external bluetooth dongles does not work.

I don't exactly have identical problem, however I found that MBP 16' Bluetooth's issues are heat related. Whenever machine heats up, Bluetooth starts to lag and/or disconnect. It's especially irritating when using Magic Keyboard, since it's input starts to lag a fair bit under load. For instance - it's virtually unusable during export of photos from Lightroom and for a while afterwards.

Latest update from Apple Support recommended removing an App related to RS232, a Kernel extension and trying a clean install.

Removed the app and FTDI kernel extension, restarted and cleared the NVRAM and the bluetooth is still not working.

It did fix the issue where in the sys info the wrong vendor showed up in the bluetooth section.

Next did a new install on the same MBP using an external hard disk, ( no apps or extra drivers installed ) and it still cannot detect any bluetooth devices.

Also tried the suggestion above of diag mode and deleting all the devices etc, did not make a difference.

I have the exact same problem with my Macbook Pro 16 inch. Did SMC reset, NVRAM reset, diagnostics said everything was fine. I ran the bluetooth explorer tool from the xcode additional tools and the Bluetooth module was just gone. Very weird, went to the Apple Store and the guy looked at me and said: I never have seen this problem ever before 😅. They are going to do diagnostics now and I hope they will come with a solution, because it is only 4 weeks old.

Thanks Swift3004, keep us posted !

My case is still open with Apple and the support team is chasing engineering for an update.

They have suggested repairing mine now, but it is only 6 weeks old and I don't think it is actually a hardware issue so pushing them to figure it out !

Hi, I got an update from the Apple Store. Turned out it is indeed a hardware problem and they are going to replace the whole logic board now. That should definitely fix the problem. But I am kind of scared to use the Bluetooth dongle again. I saw a terminal command you could execute to prevent the Bluetooth controller from switching automatically, but not sure if that works. I have to wait now until they have replace the logic board. Hope they are fast

Thanks, Apple Support has said its a hardware issue to me too. Booked in at an Apple Repair Center for them to look at it on Friday. I suspect it will be the same approach of replacing the logic board.

I found a project that will reflash the Broadcom Bluetooth module. Its a bit complex and so getting some help, will let people know if it helps - https://github.com/the-darkvoid/BrcmPatchRAM

Latest updated, and its good news !

Booked in to a Apple Authorised Repair centre, fully expecting my MBP 16 to need to spend a few days with them and parts to come from Australia to NZ.

The service guy was super helpful and ran two diagnostics on it - one called EFI and the other Mac Resource Inspector.

These are only accessible via the special WiFi network in store and not the same as we can access by holding D while booting.

They both upload results to Apples support tools for the repair centre to see online and he showed me the results.

It said the Bluetooth Module passed and the MAC address was sane.

Then after a clean boot and a delete of the /Library/Preferences/com.apple.Bluetooth.plist file my MBP 16 would pair with the techs keyboard.

Then we tested with my mouse and keyboard in store and they worked, so far its been working for 4 hours perfectly !

Hope this helps someone else save time.

Meanwhile the USB Bluetooth dongle is being locked away and never used again on the MBP 16

Hi, so I finally got my MacBook back and it works great. The command I found was quite helpful, I can pass it through to my virtual machine without macOS picking the usb Bluetooth dongle up and use it.

The command is this just paste it into terminal AT YOUR OWN RISK:

sudo nvram bluetoothHostControllerSwitchBehavior=never

to restore to default run this AT YOUR OWN RISK:

sudo nvram -d bluetoothHostControllerSwitchBehavior

Reboot after you set this variables