16-inch MacBook Pro Bluetooth issue

Hi,

I have been able to solve this exact problem by:

1. Shutdown the Mac completely
2. Plugin any supported usb bluetooth dongle while Mac is off
3. Start the Mac and login to the system
4. Use bluetooth to find and connect to some bluetooth device (propably optional step)
5. Remove the usb bluetooth dongle
6. Internal bluetooth started to work again normally

Also if this doesn't work first time you might want to repeat few times and try combinations where you shutdown the Mac with and without the dongle and startup the same way with and without the dongle.

--

Before this I also did following:

1. Reset NVRAM
2. Reset SMC
3. Reset the bluetooth module
4. Remove bluetooth.plist
5. Used bluetooth explorer.app
6. Booted to recovery (CMD+R) on startup

--

I think this is somekind of firmware related problem where call to re-enable internal bluetooth is not executed properly in certain situations leaving the bluetooth in unusable state.

Solution in my case was insipired by similar headphone jack problems on older models where Mac thought that jack was plugged in and disabled onboard speakers even if no jack was connected.

I've got the same issue and this is the first day of owning my Mac.

I have been able to get limited connectivity back by doing the following:

• Plug in the BT dongle
• Connect my wireless mouse to dongle BT
• Disconnect dongle
• Connect mouse via lightning cable
• It then shows as charging in the BT preferences list
• Disconnect cable
• Put mouse on top of keyboard (over the touch display bar thingy seems best)

By doing this I get very bad, laggy movement and clicking, like it has a super weak signal.

I also paired to my phone this way and tried sending a file to it from the Mac. It always failed to connect at all unless phone was rested on keyboard. I managed to send a photo across at 1-2kb/s.

First off, thank you so much for finding a fix. My 2019 16" MBP's bluetooth has been broken since December with no help from Apple's support.

I had the same experience as Jamie - my first dongle did not work, but the second and third I tried did. The version appears to be important: the non-working dongle was identified as version 1.00 in the system info report, but the working ones identify at versions 19.15 and 88.16. The shape is not a consistent indicator - my working and non-working dongles both use the same small semicircular shape, but come up with different versions.

Interestingly, I cannot re-break my BT now with a CSR 4.0 dongle. It temporarily breaks, but by just resetting the bluetooth module, I can get the onboard BT to restart. I plan on keeping one of the dongles as an insurance policy.

For reference, here are the dongles I have tried from Amazon's US site.

1. Not working, YCDTMYCDTMY Ultra-Mini Semi-Circle USB2.0 Small Black Bluetooth Receiver
2. Working: Wireless USB 2.4ghz EDR Bluetooth 2.0 Dongle Windows Vista/XP/2000 Plug and Play
3. Working: StarTech.com Bluetooth Adapter - Mini USB Adapter - Bluetooth 2.1 - Class 1 EDR - Bluetooth Receiver (USBBT1EDR2),Black

Hi,

I noticed right away when I took my new MacBook Pro out of the box as new that some older bluetooth devices (2 years older than my Mac) do not work perfectly with this machine. I have intermittent cutouts of bluetooth audio time to time and total failures of bluetooth link when switching between high quality audio on phone audio on the same device.

I generally think that everything that runs via bluetooth is kinda problematic and can't be trusted to work 100% of time.

Have you tried these:

• Turn your bluetooth devices completely off one at the time and check if one of them is causing inteference that stops other devices from working

• It's not bad idea to try turning off WLAN APs etc and try out if that fixes the problem

• Move to other area with the devices to rule out local inteference from other equipment

--

In past I have solved various wireless transmission problems caused by:

• Microwave oven
• Air Conditioners
• TV
• Printers
• Wireless mouses
• "Tuned" WLAN APs
• Radio amateur equipment

They are not that uncommon that one might think.

I have also seen multiple cases where someone have built bluetooth jamming devices that are designed to make bluetooth unusable at given area and one of them who I have talked with told that they stumbled upon it by accident while fiddleing with device firmware.

--

I also have the exact same problem (connected CSR BT 4.0 dongle through a dock, bluetooth stopped working). I tried Antihawks method with two different dongles, but was not successful.

1. I tried a cheap dongle (https://vod.ebay.de/vod/FetchOrderDetails?itemid=191930036075&transid=1745988835009&ul_noapp=true), could not see any bluetooth devices at all, but repeated the procedure over and over again. After one of several restarts my Macbook Pro could suddenly see my iPhone without the external dongle connected and even connect to it, but after closing the connection I could not reproduce this success.
2. Ordered another dongle (Startech Bluetooth Adapter USBBT1EDR2 USB) and tried it. This time I could easily find my devices (iPad, iPhone), but I never got to the point where the internal module would find any devices after I unplugged the dongle. I did SMC resets, reset the bluetooth module, NVRAM reset, deleted the .plist, booted into safe mode, but nothing worked.

I am really desperate right now as I invested a lot of time (and money) in solving a problem that should be solved by the manufacturer of a 6000 EUR professional notebook that is still under warranty. I have to use the device on a daily basis to do my job and cannot give it away even for 3-4 days and I am really annoyed by the fact that every apple employee I talked to could not offer any solution for this problem.

Maybe anybody here has a hint what I could try to make it work? Was it important for you guys to connect to Android devices or could you also make this solution work by connecting to Apple devices?

Any help is highly appreciated.

Thank you!

Happy to finally delete this page from my bookmarks.

Here's what worked for me. You will need a device that can pair via Bluetooth for data transfer (audio only didn't work for me) such as a Windows PC or Android Phone.

1. Turn on Bluetooth
2. Reset SMC
3. Reset BT Module and remove devices in BT debug menu (option+shift+click)
4. Power off
5. Plug in 2.0 BT dongle
6. Power on. At this point your dongle should be picked up by the OS.
7. Grab your second device and attempt to connect to MacBook using Bluetooth
8. macOS prompts connection code, cancel connection
9. Remove dongle
10. Done

At first I had this issue:

You will see very soon if your dongle is working or not because it has to be directly recognized by mac. If you see that when you connect your dongle your Bluetooth icon changes temporary to an error icon it won't work. Your dongle has to be able to search for devices.

I managed to make it work by making multiple attempts of connecting/disconnecting and rebooting with/without the dongle connected. You will know it's working because other devices can pick up your Mac.

Best of luck, and don't give up. If you got your hands on a 2.0 BT dongle already, give it one more try.

Eternally grateful to @AntiHawk who figured this out, Apple should send you a check ;)

Boris was incredibly kind to send me the dongle that could fix the problem from Switzerland to the Netherlands. Once I received the dongleI undertook the following steps to make it work:

1. sudo nvram bluetoothHostControllerSwitchBehavior=always
2. Unplug all Bluetooth dongles
3. Turn off Bluetooth
4. Reboot the MacBook (I turned it off and back on)
5. Log in
6. Plug the Bluetooth 2.1 dongle in
7. Verify that it works by seeing names of Bluetooth devices pop up in the Bluetooth settings window
8. Take the Bluetooth dongle out
9. The MacBook's internal Bluetooth module is now once again working.
10. sudo nvram bluetoothHostControllerSwitchBehavior=never

Thank you so much, Boris, for helping a complete stranger. That gesture alone means more to me than actually having helped solve my problem.

Hi guys,

I was having the same issue, described in this thread. Fortunately, being very impatient (waiting for the dongle to arrive), I read up on nvram executable, it seems there is a way to list all variables using 'nvram -p' command. I noticed that BluetoothInternalController description was referencing my external dongle. For the next step I issued a command to delete all firmware variables and restart the Mac with following commands (remove external dongles before performing this):

• sudo nvram -c
• sudo reboot

I know that some of you might say that it's something that I should not have not done, but it seems to me that after restart, all firmware variables were regenerated anyways (and BluetoothInternalController has a correct value. Now my internal Bluetooth is discovering devices and working as expected, without any dongle manipulation!

I've just managed to fix this issue in a strange way, and without requiring any BT 2.0 dongle.

Background (don't know if it's mandatory for the fix):

I was affected by this problem for a couple of months, after reading the answers in this thread I've tried buying this dongle and tried AntiHawk's fix:

https://www.ebay.com/itm/Small-Portable-Bluetooth-2-0-USB-Dongle-Adapter-For-Laptop-PC-Win-XP-Win-7-Win-8/353265753062?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

But it did not help (and my mac couldn't even use it to find any devices).

I've tried plugging in and out several times, but still didn't work.

I've then ran this command:

sudo nvram bluetoothHostControllerSwitchBehavior="never"

And kept it this way while trying to find a new dongle to purchase.

Several days later, I've tried the steps I mention below in this post (without even using the BT 2.0 dongle), and it magically started working.

I have no idea if the fact I've managed to fix this issue is related to the fact I've previously did plug the BT 2.0 dongle or not, but I'm posting my method here so others will try it too, with or without having previously using BT 2.0 dongle.

Would love to hear if this method worked for anyone else.

My steps were as follows:

• Open terminal and run these commands: (Let bluetoothd continue to run in the terminal window)

sudo nvram bluetoothHostControllerSwitchBehavior="always"
sudo nvram -p
bluetoothd

• Open the bluetooth menu and try connecting to a device.
• Everything works 🤯
• Closing the terminal window (terminating the running bluetoothd command).
• Running this command to prevent future problems:

sudo nvram bluetoothHostControllerSwitchBehavior="always"

• Everything still works.

The same thing happened to me too. I have a brand new 16-inch MacBook Pro and, when I connected my CSR BLE Dongle through the CalDigit adapter, my internal Bluetooth module stopped working. I did everything that has been suggested in this thread but no luck so far. I was also using a Virtual Machine....

For more reference, I also found using Bluetooth Explorer that it's reporting an error:

Initializing Bluetooth...
Bluetooth Support Initialization complete.
updateChainPower error: -3903
2020-04-09 14:36:34 +0000 Apple80211Get(APPLE80211_IOC_BTCOEX_MODE) returned error -3903
updateChainPower error: -3903

And, using a free App named BlueSee, I can see my devices but with a terrible RSSI (both devices were on top of my keyboard during the test):

I had the same problem with a 2019 27' iMac. I plugged in the CRS USB Bluetooth dongle and after that my bluetooth became a lot unstable. The mouse was literally unusable and when using the AirPods the connection would drop randomly. I did a lot of research but nobody found a solution.

I did all of the following:

-Restore bluetooth module

-Delete .plist preferences

-Reset SMC

-Reset NVRAM

-Reinstalled macOS - To a previous version (Mojave) and to the newest one (Catalina)

-Run hardware diagnosis - Everything was fine

Nothing worked, bluetooth continued to fail and drop. I even talked to Apple Support and neither them could help me. All was leading to a hardware issue but I refused to believe a simple usb dongle messed up the hardware itself.

As someone stated before, the problem in Bluetooth Explorer was showing up as the following error: updateChainPower error: -3903, which means that the bluetooth module is not receiving enough power to maintain a stable connection. That seemed strange so I decided to check on System Report to see if Wi-Fi and Bluetooth loaded well. As I expected, the Wi-Fi tab was showing null on all Software Versions. 

That, somehow, light a bulb in mi brain and I thought about the EFI partition as the EFI is the one that has to preload all the firmware data information to pass it to the operating system. I tried to edit the EFI partition but it seemed impossible without erasing all of the disk, so that is what I did.

The first time I reinstalled the OS I didn't erase all of the disk but only the one that contains the operating system so that explains why a fresh install wasn't working. I ran diskutil to erase all the contents of the hard disk including the EFI partition. Now, with a completely fresh disk drive, I installed macOS and the problem got fixed because the EFI partition was now created from scratch with all of the configuration files needed. Now, bluetooth and Wi-Fi work like a charm without problems.

tl;dr.

Delete manually the EFI partition completely and reinstall macOS from scratch, that restores configuration files on the boot loader that make bluetooth working again.

Dalogan72 wrote:

I posted the link yesterday, so people can even buy it from Amazon.

https://www.amazon.co.uk/gp/product/B00IMQ58NI/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 did not show whether it is CSR. Can you connect it and check System Report?

The USB dongle in AntiHawk's screen is a CSR.

This was the module that I purchased from Amazon:

https://www.amazon.co.jp/gp/product/B00WUUZSMI?pf_rd_r=GP9PRYD1573FK2DNNZB8&pf_rd_p=98c49dab-e38e-4b01-90d8-75eabcf3cdee

The module is unbranded but it shows up as: Bluetooth V2.0 Dongle 0x0a12 0x0001.

I got both my MacBook Pro 16" and 13" working again. I had purchased a Bluetooth 2.0 dongle from Amazon:

https://www.amazon.co.jp/gp/product/B0044BYEGW/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

This one was functional as it would search in Windows but when connected to the Mac, it wouldn't search for any Bluetooth Devices.

I then purchased this one:

https://www.amazon.co.jp/gp/product/B000YHUR0M/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Yeah, this one was more expensive but It was a branded product. This one worked perfectly. I paid $26.00 for it.

The USB details of the dongle are:

Anyway, thank you very much for posting this information. You have saved me another trip to the Apple Store and weeks without the Laptop.

Jamie

jamiefromkirkcaldy wrote:

For number 2, can you post a couple of screenshots from the System Information when the No 2 dongle is plugged in?

If you can also post a screenshot from the USB section when you click on the USB Dongle.

That will give us a little more information to see the exact chipset and version.

Hi Jamie,

glad you asked! Here is a picture showing chipset etc. of the second module (Startech Bluetooth Adapter USBBT1EDR2 USB):

Maybe one of you has found a working module in Germany? Or is anybody willing to send me their proven to work module to Germany? Of course I would pay the shipping, buy a beer and send it back after fixing my Mac.

Cheers!