Syn3 Updater will automatically detect the best install mode for your specific use case based on the information you provide during configuration
There are 3 install modes that will be referred to as Autoinstall, Reformat and Downgrade, downgrade is basically the first 2 combined.
By default Syn3 Updater will use Autodetect this is the automatic detection mode, this can be overridden by changing the value in the Settings Tab however unless you know what you are doing you should keep this at Autodetect.
Below is a brief description of what each mode does and the pros and cons to them.
Autoinstall
This is the standard SYNC update procedure, think of it like a simple windows update or phone update. It simply copies the new files to the eMMC (storage) and then replaces the existing file or files with it.
Pros
The "official" method
Works well for simple single package upgrades or small package collections such as a APPS update with maybe 2 or 3 other packages
Cons
Not great for upgrading the entire operating system and maps at the same time as there isn't enough space to store all this at one time, there are workarounds but if a reformat is possible this is preferred by CyanLabs
You can't use this method to go from 1.x , 2.x or 3.0 to 3.4
You run in to MEM_ERR's often on smaller sized APIM's due to the above mentioned reasons
Can leave behind some residual packages for
Doesn't indicate what the installation is actually doing, just shows "Installing"
Reformat
This uses a official (all packages must be signed by ford) tool that was leaked in to the wild, this tool will do what essentially a format and re-install of your computer would do, it completely removes all (almost) data and reformats the eMMC (storage) ready for a fresh configuration. Literally without this leaked package none of this would be possible.
Pros
Complete fresh wipe, no left over data or anything to slow or clog the system
Can be used to upgrade from 1.x, 2.x and 3.0 to 3.4
Faster to install than a standard AutoInstall (assuming you want to install the whole system), Maps updates can take over an hour via AutoInstall but if done via a reformat it won't take more than 1 hour for the entire EU package.
You have a progress bar of what is actually happening rather than just saying "Installing"
It skips any ESN checks allowing for maps to be installed without the correct ESN licenses
Cons
The tool was blacklisted and is not usable if you are on version 3.4.19274 or above, it will result in PKG_ERR04. People believe this is blacklisted not because ford decided to block it but rather that it can result in a black screen on cars that have a certain screen as the drivers have changed, it's likely there is a newer package that ford use but it's unlikely to be leaked any time soon.
If you want to install a single package, let's say Gracenotes, you won't be able to without reinstalling the entire operating system again.
Doesn't work on certain 2020 screen/APIM combinations, more specific information is still being investigated by CyanLabs and other communities
Downgrade
This is a hybrid method combining parts of the AutoInstall and Reformat as one. Essentially when reformat is used it will downgrade your post 3.4.19274 SYNC to 3.3.19052 this allows for the reformat tool to be used. once at this stage everything is the same as the reformat.
Pros
Allows for using the reformat tool on 3.4.19274+
Same as Reformat
Cons
Sometimes you don't have enough storage space to downgrade to 3.3 from 3.4.19274+ which can require various troubleshooting, luckily this has been made more automated in the Utility tab of Syn3 Updater 2.0
How Syn3 Updater chooses
NOTE THAT IF YOU HAVE MY20 PROTECTION ENABLED, THIS WILL FORCE AUTOINSTALL AND THE BELOW DIAGRAM IS OBSOLETE
