iPhone Sync Session Failed to Start Error – Can’t Sync iPhone 4 with iTunes 12

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Computer Repair Sacramento CA – Jonathan Warner Knowledge Base: Steps to resolve iPhone sync session failed to start error message when you can’t sync iPhone 4 with iTunes.

iPhone Sync Session Failed to Start Error – Info

This error usually occurs when when trying to sync iPhone with iTunes.

iTunes will show your iPhone device as connected. If iTunes WiFi Sync is enabled, it will be available from your device settings menu. But, iTunes sync fails to start. The session seems to begin, but iPhone sync stuck step 1 of 6 (in my case). After a couple of minutes, it times out and the iPhone sync session failed to start error appears. As a result, you can’t sync iPhone 4 with iTunes over WiFi or when using a iPhone sync cable.

Here are steps that usually resolve this issue. The error resolution steps are arranged in modules. Try the modules one at a time as some early steps may actually fix the problem. If you still can’t sync iPhone 4 with iTunes, move on to the next module in order.

iPhone Sync Session Failed to Start Error – Module 1

Confirm that your iPhone is listed in iTunes under Devices in the left side.

Summary: Reboot All

  1. Restart iPhone
    1. How to power off and restart iPhone:
    2. Press and hold the sleep wake button (iPhone top right)
    3. When the the Slide to Power Off message appears, slide the button to the right
  2. Reboot computer
  3. Open iTunes – Try to sync iTunes to iPhone

iPhone Sync Session Failed to Start Error – Module 2

Summary: Update All

  1. Update iTunes to the latest version (if necessary)
  2. Update iPhone software to the latest version (if necessary)
  3. If any updates were applied, reboot computer and restart iPhone.
  4. Open iTunes – Try to sync iTunes to iPhone

iPhone Sync Session Failed to Start Error – Module 3

Summary: Delete iPhone Backups and Reset Sync History

Reason: Each time you sync, iTunes does not create new backup files, it only overwrites or appends old backups. If a backup become corrupt, it can cause an iTunes sync error even result in a iTunes sync failed.

  1. Open iTunes – Open Preferences
    1. How to Open iTunes Preferences:
    2. Windows: Click Edit on the menu bar, click preferences, Click the Device tab
    3. Apple Mac: Open iTunes – COMMAND + , (comma) to open preferences, Click the Device tab
  2. If multiple devices appear under Device Backups, select the correct one.
  3. Click Delete Backup button
  4. Click Reset Sync History button (if applicable)
  5. Close iTunes
  6. Restart iPhone (instructions above)
  7. Reboot computer
  8. Open iTunes – Try to sync iTunes to iPhone

In most cases, the above steps will resolve the iPhone sync session failed to start error and fix iPhone sync problems.

Need further iPhone help or personalized iPhone training? Contact Jonathan for Computer Repair Sacramento CA today!

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12 thoughts on “iPhone Sync Session Failed to Start Error – Can’t Sync iPhone 4 with iTunes”

  • Zemma

    Just wanted to say thank you! I bought a new iPhone 5 today and my iPhone 4s wouldn’t back up to my desktop (which I need to do to transfer apps, etc.) Was getting the ‘sync fail’ message…module 1 did it! Restarted the old phone and the old desktop and it synced. Sometimes simple really does work. 🙂

  • Jonathan Post author

    Hi Chris, in trying to fix the iPhone Sync Session Failed to Start Error, I haven’t encountered that particular behavior before, were you able to resolve it?

  • Chris

    Thank you! I deleted the backup devices and rebooted both units, the iPhone and PC, then when iTunes started up it suddenly asked me to authorize the computer, which I did and it went from sync to back up 4 of 8. The only annoying thing is that it takes so long to sync. It’s been 30 minutes and it’s still at the same 4 of 8. Should I worry, or let it keep going. And how long will that take? Is this normal? Thanks again for sharing your expertise with us. Much appreciated!

  • Jeff

    Thank you so much for this (I have clipped it in Evernote in case i need to read it again some day!); this problem has been really irritating given I have a lot of new music I have been looking forward to hearing!!

    For the record, I went into DFU mode, then deleted the backup and this worked like a charm. : )

  • Jen

    Thank you so much for these, this has happened to me multiple times and most of the time these work, but for anyone reading this and it hasn’t worked for them, you can end the iTunes task by pressing Ctrl+Alt+Delete and selecting Task manager, then right click on iTunes or iTunes.exe and ending the task. Then, reopen iTunes and hopefully your phone/iPod will sync.

  • Shane Nowlin

    Excellent feedback forum! I’m most impressed to say the least, and your steps to resolve these most grueling issues are well detailed. 10/10 service and support help.

    P.S. This did resolve my issue with my iPhone and I thought it was a nice touch that your website resolutions you posted had more than one method for the same problem, that way it may work for different circumstances and different people. =]

  • Thanks for this clear and helpful information.

    Thanks for this clear and helpful information.

  • Gambit Charles

    none of the steps above resolved my issue. My ipad syncs with no problem. Yet my iphone can’t seem to sync and this message would display “sync failed to start.”