On the covered Apple iPhone or iPad, 2009 means Apple lists 2009, with 2000, 2001, 2002, 2005 and 2006, among the errors that point to the USB connection, cable, port or computer. First, use the cable that came with the device.
Try in this order
0 of 9 completedWhat to do first
ReversibleUse the cable that came with the device.
Correct only the documented fault domain
ReversibleApple's USB checks, trying again after each: use the USB cable that came with the device, or another Apple-certified cable; switch to a different USB port on the computer, but not the port on a keyboard, which often lacks the power to update or restore; and try a USB port on a different computer. Apple's steps to try first: install software updates on the Mac, or update iTunes or the Apple Devices app on a Windows PC, then follow the steps for your error number.
Use the cable from the box and a rear port
ReversibleApple's restore-error guidance for 2009 starts with the original USB cable, then a different USB port on the computer. Keyboard USB ports often lack the power for a restore, so plug straight into the computer.
Try another computer and the current software
ReversibleSwitch to a different computer if you can, and make sure the Mac or Windows PC runs the latest system and Apple Devices or iTunes.
Use recovery or DFU mode
ReversibleIf the normal restore keeps failing, putting the phone in recovery mode, or DFU mode for a deeper connection, often lets the restore finish.
Try the other side of the computer
ReversibleMoving the cable from a front port to a rear port, or from one side of a laptop to the other, can change the electrical conditions enough for an unstable restore to finish.
Avoid hubs and adapters
ReversibleA USB hub or a USB-C adapter can drop the connection under the heavy data flow of a restore, so use a direct cable. If your computer only has USB-C, use a cable that is made for it rather than an adapter.
Test the cable and port with a second device
ReversiblePlug the same cable into a different iPhone or iPad, or another USB device, to see whether the cable itself is sound. A cable that works for charging may still fail under the heavy data load of a restore.
Close other programs that use USB
ReversibleQuit backup tools, phone managers and any program that polls the device. A second program talking to the iPhone during the restore can interrupt it and set 2009.
Evidence ledger
Sources behind this answer
Exact questions
Common questions about “Apple iPhone or iPad code 2009”
What does 2009 mean on a Apple iPhone or iPad?+
Apple lists 2009, with 2000, 2001, 2002, 2005 and 2006, among the errors that point to the USB connection, cable, port or computer.
Does iPhone error 2009 mean the phone is broken?+
Usually not. It means the computer lost its connection to the phone during the restore, which is most often the cable, the port or interrupted software.
Can security software cause error 2009?+
Yes. Security software that interrupts the connection is one of the listed causes; turn it off for the restore and back on afterwards.
Can a USB hub cause error 2009?+
Yes. Connect the phone straight to the computer with no hub or dock in between, because a hub can drop the connection during a long restore.
Will I lose my data if the restore fails with 2009?+
A failed restore can leave the phone in recovery mode. Data that was backed up to iCloud or the computer can be restored afterwards, which is why a backup comes before any restore.
What does error 2009 mean?+
Apple lists 2009, with 2000, 2001, 2002, 2005 and 2006, among the errors that point to the USB connection, so the link between the device and the computer is the suspect.
Why does it fail partway through?+
A restore moves a lot of data, and a connection that holds for a few minutes may fail under the load, which is why a better cable or port helps.
Is it a software problem?+
Rarely; updating the computer and the Apple app is worth doing, but the cable and the port are the likelier cause.
Will recovery mode help?+
It can, because it bypasses a damaged operating system, but the connection still has to be stable.
Is 2009 related to 4013?+
Both belong to Apple's list of USB-related errors, but they appear at different moments, with 2009 usually as the connection drops.
Should I try a different Apple ID or network?+
No, 2009 is a physical connection problem, so the account and the network are not involved.
Does it help to restart the device first?+
Yes, restart the computer and the device before you try again, since it clears stale USB state.
What if it happens every time?+
Try a second computer, since a faulty port or driver on the first computer is a common cause.