MobileMe: Troubleshooting iPhone or iPod touch sync issues

Resolution

Important: You should make a back up copy of your data before proceeding with troubleshooting.  

Basic troubleshooting

If you make changes during any of the steps below, try syncing again with MobileMe on your iPhone/iPod touch. 

1. If you are syncing calendars or contacts, view the data on MobileMe Calendar or MobileMe Contacts. If the data does not appear to be correct there, the issue is not with your iPhone or iPod touch.  If you are syncing using a Mac, see this article for more information.  If you are syncing using a PC, see this article for more information.
2. Make sure your iPhone or iPod touch is up-to-date with the latest software.  iPhone OS 3.1 or later is recommended for all MobileMe members using an iPhone or iPod touch.  More information about the iPhone OS 3.1 update is available here.
3. On your iPhone/iPod touch, make sure you are able to connect to the Internet.  For example, open Safari on your iPhone/iPod touch, then browse to http://www.apple.com .  MobileMe requires an Internet connection to sync.  (A 3G or WiFi connection is recommended during setup or when following many of the steps below; they may require several minutes via an EDGE connection.)
4. Confirm that a sync is not already occurring.  If a sync is occurring, the activity spinner (in the status bar) will display while looking at Safari Bookmarks (if Bookmarks are currently syncing), Calendar (if calendars are currently syncing), or Contacts (if contacts are currently syncing).  If a sync is occurring, wait for the sync to complete, and then see if your data is up-to-date.  
5. Make sure you are looking at your full set of contacts or calendars.  When configuring your MobileMe account in iPhone OS 3.1, you will have a choice to Merge or Don’t Merge your data.  If you choose Don’t Merge, your MobileMe data is kept separate from the data that was already on your device.  In Contacts/Calendars, tap the button in the upper left corner until you are able to see all Groups or Calendars, and verify that you are looking at your MobileMe data. 
6. Confirm that you are able to get your MobileMe Mail on your iPhone/iPod touch.  If you receive an alert message when attempting to get your MobileMe Mail on your iPhone/iPod touch, your account may not be configured correctly, or you may not have a reliable internet connection.  If the alert message is about your username or password being incorrect, go to the next step.
   
7. Verify your MobileMe account is configured correctly on your iPhone:
   
   
   1. On the home screen, tap Settings > Mail, Contacts, Calendars.
   2. Tap Fetch New Data, and make sure Push is turned On.  Tap Mail... to go back one screen.
   3. Tap your MobileMe account.
   4. Tap Account Info and check the Address field.
   5. Verify that your address appears correct (it should appear as your MobileMe email address, such as membername@me.com or membername@mac.com).  If your account does not appear as expected, see the “Delete and re-add your MobileMe account” under the Advanced Troubleshooting section below.
   6. If you received an alert about your username or password during step 6, delete and re-enter your MobileMe password, and then check your Mail again.  If your still receive the same message, try logging into www.me.com .  If you are unable to log in, see this article.
   7. If your account does appear to be entered correctly, go back one screen and confirm the sliders for the data that you want to sync are set to On.
       
8. Verify that your iPhone/iPod touch is connected to the MobileMe service.  To confirm this, visit http://www.me.com/account from a computer and click Find My iPhone.  Because Find my iPhone relies on the same connection as MobileMe Sync, your device should be listed as "Online" for as long as it has an active Internet connection.  If the device does not appear as expected, please see this article about troubleshooting Find My iPhone. 
9. Restart your iPhone or iPod touch: Hold the power button until "slide to power off" appears.  Slide to power off.  After it is off, press the power button to turn it back on.
10. Wait an hour and try again.  Apple may temporarily disable an account from syncing with MobileMe if it is determined that an account may be taking longer than normal to sync.  By waiting an hour and trying again, this allows for the previous sync to complete.  If you find your account encounters the issue again, go to the Advance troubleshooting section. 

Advanced Troubleshooting

If the above steps do not resolve your issue in iPhone OS 3.1, you can try these advanced troubleshooting steps:

Turn all syncing off and then back on

From the home screen, tap Settings > Mail, Contacts, Calendars, and then tap your MobileMe account. Tap the sliders off for each account that your are syncing.  If prompted to do so, tap Keep on My iPhone/iPod touch.  Turn your iPhone/iPod touch off and back on, then re-enable syncing.  If prompted to do so, choose Merge with MobileMe.  Wait a few minutes, and try syncing again. 

Isolate the issue to a specific data type

If the above did not resolve the issue, once again turn off all syncing, and then test each data type one at a time.  For example, if Contacts syncs successfully, but Calendars does not, focus your troubleshooting on Calendars. 

If you have isolated the issue to either Contacts or Calendars that are not syncing successfully (one works, the other does not), see this article recommendations about how to clean up that data on your Mac or PC, as it is likely causing the issue.

Delete and re-add your MobileMe account

If none of the above steps resolve the issue, make sure you have a copy of all Contact, Calendar, and Bookmark data on your iPhone saved on your Mac/PC.  From the home screen, tap Settings > Mail, Contacts, Calendars, and then tap your MobileMe account.  Tap Delete Account. (If prompted to do so, choose Delete from My iPhone.) Restart your iPhone/iPod touch.  After it restarts, on the Mail, Contacts, and Calendars screen, tap Add Account > MobileMe, and set up your account again.