If you have a MacBook Pro from 2016 onwards and you have Touch Bar, your Mac does not have a single processor, but two. Well, the Touch Bar at least in the 2016 and 2017 models (we will see what happens in the future) has a separate chip from the central chip of your Mac. For this reason, the steps we usually take when we sell or transfer a technological equipment and Obviously we want to leave no trace of us anywhere, this time it is not enough to completely erase the hard drive. Apple recommends that you do the following.
Therefore, as the Touch Bar collects information, We must perform some actions from the terminal, to ensure that personal information does not travel in our old team. In principle, this data is stored securely in Secure Enclave. If you are looking for information on the Apple page about how to delete the information from the Touch Bar, you will not find more than one guide to use the Apple bar. Instead, you can always go to a guide support which invites us to take a few steps from the terminal and delete the information from the Touch Bar. To do this, you must follow the following steps:
You can erase any information stored by Touch Bar before selling or giving away your MacBook Pro.
First, start from macOS Recovery: Press and hold Command-R on your keyboard immediately after pressing the power button to turn on your Mac, or immediately after your Mac begins to restart.
When the macOS Utilities window appears, choose Utilities> Terminal from the menu bar. Type this command in Terminal:
xartutil --erase-allPress ESC, type Yes, when asked if you are sure, and then press ESC again. Finally, choose Terminal> Exit Terminal and proceed to the next step.
If you have sold your MacBook Pro with Touch Bar and you have not done these steps, nothing should happen, but it does not hurt to do so.