What is iPhone error 4003?
iPhone error 4003 is an error that usually occurs during an update or restore via iTunes. It could either be a software issue or a USB issue. The error may occur when there is an issue with the USB port, cable, dock, or hub. You may also experience the error if the device gets disconnected during the restore.
How can you fix iPhone error 4003?
Some of the solutions to this error include troubleshooting USB connection.
Please see our in-depth walk-through solutions below.
1. Troubleshoot USB connection
iTunes may diagnose that a faulty or low-speed USB cable or a software is interrupting the communication between iTunes and the devices when iPhone error 4003 occurs. Please see the guidelines below that might help fix the problem.
- Remove all USB device except your mouse and keyboard.
- Use another high-speed USB cable, to determine if your USB cable is faulty.
- Try a different dock connector or no dock, to determine if your dock is faulty.
- Do not use USB extension or computer case USB ports. The USB extension might be slow in term of data transfer. Use USB port directly connected to the motherboard.
- Close all software that can interrupt the USB connect, such antivirus and virtualization apps.