Updating to MacOS Monterey on MacBook Pro 2015, Firmware problem

Are you using a third party SSD in this laptop? macOS 12.x Monterey will refuse to install the first time if a third party SSD is installed internally. Reinstall the original Apple OEM SSD and install macOS Monterey so the laptop's system firmware gets updated. Once you do this, then you can reinstall the third party SSD internally and upgrade to macOS Monterey.

If you don't have the original Apple OEM SSD, then you can try to manually trigger the system firmware update by using the following instructions which I got from the OP in this Reddit post and in this other article.

https://www.reddit.com/r/MacOS/comments/qm3rv0/macos_monterey_update_without_the_original_apple/

https://tinyapps.org/blog/202110270700_monterey-third-party-ssd.html

These instructions are just having you temporarily disable System Integrity Protection (SIP) so you can extract the firmware updater from the Monterey installer app and tell the laptop's NVRAM to boot the firmware updater so it will update the laptop's system firmware. The "bless" command at Step #15 is what tells the laptop to boot that firmware file which causes the firmware updater to run at boot. It is the Monterey installer which is preventing the firmware updater from running.

The instructions in those two articles are a bit confusing, so I will try to rephrase them here with a bit more detail. You do this at your own risk. If something goes wrong, your laptop may become a useless brick.

Make sure your power adapter is connected to the laptop and providing power to it. It would be best if the battery is at 100% charge level as well just in case you lose power or the charger gets disconnected during this process.

Check your laptop's system firmware is at 195.0.0.0.0 or greater. You do this by holding the Option key while clicking on the Apple menu & selecting the first item. On the right pane look "System Firmware Version" or "Boot ROM Version". If this version number is not greater than or equal to 195.0.0.0.0, then just stop since you cannot update the system firmware using this method.

If your System Firmware or Boot ROM version is 195.0.0.0.0 or greater, then follow these steps:

0) Write down the "Model Identifier" for your laptop (should be the second item on the right pane of the System Profiler). You will need this value later on. I believe it should be either "MacBookPro11,4" or "MacBookPro12,1" depending on whether you have the 15" or 13" (2015) model.

1) Boot into Recovery Mode using Command + R. You will hold these two keys down immediately after hearing the startup chime.

2) Launch the Terminal app from the Utilities menu on the menu bar

3) Enter the following command to disable System Integrity Protection (SIP). This is just temporary & will be re-enabled later.

csrutil  disable

4) Quit the Terminal app and click the Apple menu to select "Restart..." to boot back into macOS normally.

5) Copy the following path into the Clipboard (highlight the following line and press Command + C, or select "Copy" from the Edit menu):

/Applications/Install macOS Monterey.app/Contents/SharedSupport

6) Click on the Finder's "Go" menu & select "Go to Folder ...". Paste the contents of the Clipboard into the window that just opened, then click the "Go" button. This will open a Finder window which should show a single file "SharedSupport.dmg".

7) Double-click the "SharedSupport.dmg" file to mount it.

8) Open the "com_apple_MobileAsset_MacSoftwareUpdate" folder.

9) Copy the only .zip file within that folder to your Downloads folder (the file is about 11.49GB in size)

10) Once the file is copied, Eject the mounted "Shared Support" item by clicking the eject button for it on the Finder's Sidebar

Continued in my next post since I exceeded the 5,000 character forum limit........

if the message says something like 'a firmware update is required', it may just be letting you know that it will FIRST update the firmware, THEN install the software.

What is the EXACT wording of the message?

¿what is the date of your most recent Trusted backup, and by what method?

If something goes wrong, you may need that backup.

Continued.....

11) Within the Downloads folder, double-click the .zip file you just copied in order to extract the contents.

12) Now open the folder that was just created (it will have the same long name as the .zip file). Then navigate to the folders within it: AssetData/boot/EFI/EFIPayloads.

13) Now you need delete all files within the "EFIPayloads" folder except for the one file which matches your laptop's "Model Identifier" which you wrote down at the beginning. The "Model Identifier" is abbreviated in these file names so "MacBookPro11,4" will be "MBP114" and "MacBookPro12,1" will be "MBP121". Make sure only the file with the abbreviated model identifier for your laptop is left within this folder.

14) Double-check the name of the remaining file matches the "Model Identifier" for your laptop. If you choose the wrong file, then you will end up with a brick for a laptop.

15) Launch the Terminal app and begin typing the following (or better yet copy & paste the next line into the Terminal app. Make sure there is at least one space after "--firmware ".

sudo  bless  --mount  /  --verbose  --recovery  --firmware  

16) Go to the Finder so you can drag & drop the firmware file still remaining from Steps 13 & 14 onto the open Terminal window. This will append the correct path of the firmware file on the line you typed in Step 15. You will end up with a line looking something like this (keep in mind this is just an example of what it will look like since the path to the firmware file will be slightly different for you depending on your username & firmware file for your specific Mac). Do NOT Copy & Paste this example (I did make an intentional name change for the path in my example so people don't accidentally brick their Mac by copy & pasting this example. This is only meant to give you an idea of what you should see.

sudo  bless  --mount  /  --verbose  --recovery  --firmware  /Users/hwtech/Downloads/9844b3b223z74d3d37d1d366b898d39442ccc28bg/AssetData/boot/EFI/EFIPayload/MBP114.fd

17) Press the "Return" key to submit the command once you are sure it is correct and you have the correct firmware file to match the "Model Identifier" for your laptop.

18) You will be prompted for your admin password. Nothing will appear on the screen as you type the password. Press the "Return" key to submit your password.

19) Press the Caps Lock key so the Caps Lock LED lights up.

20) Click the Apple menu and select "Shutdown ..."

21) Once the laptop completely powers off the Caps Lock LED should go out. Make sure the power adapter is connected to the laptop, then power on the laptop. The laptop should run the firmware updater to update the laptop's firmware. Your laptop may reboot a couple of times.

22) Once the laptop boots into macOS, go to the System Profiler and verify the "System Firmware" or "Boot ROM" version is now greater than when you checked before starting with Step #0.

23) Now reboot into Recovery Mode using Command + R so you can launch the Terminal app within Recovery Mode and issue the following command to re-enable SIP again:

csrutil  enable

24) Quit the Terminal app, and select "Restart ...." from the Apple menu.

25) You should now be able to run the macOS 12.x Monterey installer without any issues if the system firmware was successfully updated.

Make sure you are willing to accept the risk that selecting the wrong firmware file can brick your Mac making it completely unusable. Even when using the correct firmware file, there is always a risk to firmware updates going wrong. Losing power, or interrupting the process can cause the system to become a brick. Sometimes the firmware update process will fail due to a latent hardware issue that has gone undetected. Even Apple caused some people's 2014 MBPro laptops to become bricks when originally installing macOS 11.0 Big Sur at launch....Apple later prevented the 2014 MBPros from updating to Big Sur until Apple released a fixed version several months later.

https://www.google.com/search?q=macos+installer+firmware+update+bricks+macbook+pro+2014&sourceid=chrome&ie=UTF-8

The firmware is stored in a private store on the processor card, so removing the drive after a firmware update does NOT remove the updated firmware.

You might also be able to buy a used genuine Apple SSD (any size) for EXACTLY this model Mac from a seller on eBay, but there are some risks there as well. Some sellers are very savvy, other are completely clueless about what they are selling, and its condition. If you choose this route, buy only under conditions that a non-functional device can be returned for refund.

Grant Bennet-Alder wrote:

You might also be able to buy a used genuine Apple SSD (any size) for EXACTLY this model Mac from a seller on eBay, but there are some risks there as well. Some sellers are very savvy, other are completely clueless about what they are selling, and its condition. If you choose this route, buy only under conditions that a non-functional device can be returned for refund.

The OP must be extremely careful to get an Apple SSD made for this exact model 2015 laptop. While Apple SSDs from 2013 to 2017 all have the same Apple proprietary SSD connector, but macOS will refuse to work at all with some of them (personal experience) even though the same SSD will work perfectly fine with Linux. Definitely important to select a seller who advertises all the technical details & to confirm the SSD is guaranteed to work on the 2015 model or get a full refund.