TROUBLESHOOTING

iPhone Update Error 4013

By iPhone Update Editorial Desk · Reviewed September 19, 2026

DO THIS FIRST

Change the cable and USB port first. Error 4013 is usually a dropped connection during a firmware write, not a dead logic board.

What you are seeing

Finder, Apple Devices, or iTunes reports error 4013 while updating or restoring.

Why this happens

The restore daemon lost the device while writing NAND. Hubs, damaged cables, and ports that cannot supply stable USB data are the common cause.

Do this in order

Use an Apple or MFi cable plugged directly into the computer, not a hub or monitor port.
On Windows, try another USB port. On Mac, try a different USB-C port.
Force-restart the iPhone, reconnect, and choose Update before Restore.
Disable security software that intercepts USB devices, then retry once.
If 4013 repeats on two cables and two ports, try Recovery Mode Update on a second computer.

If it is still broken

Persistent 4013 across computers can be hardware. That is an Apple Store or AASP diagnosis, not another identical restore on the same cable.

Questions this page actually answers

Does 4013 mean the NAND is failing?

Sometimes, after cables and ports are ruled out. Do not jump to board repair on the first occurrence.

Should I use DFU immediately?

No. Recovery Mode Update is the next step. DFU Restore erases data and is later.

Next useful pages

Sources

Prepared by the iPhone Update Editorial Desk. Independent technical reference. Not affiliated with Apple Inc.