My ZIO wasn't able to access data out of the box, and their tech support walked me through this process. I'm posting it here in case anyone else has the same problem.

  1. Dial ##4357*. RTN menu will appear.
  2. Select View.
  3. Scroll to bottom and select Reset. Phone will reset.
  4. When it comes back up, dial *228. After programming, phone will reset again.
  5. At this point, my phone refused to reboot, and displayed "mARM Err Fatal" in the top left corner of the screen. I did a hard reset by removing and replacing the battery.
  6. After this, the phone started normally and voice, text, and data were all working!


Simply doing a factory reset from the mass storage / USB menu did not fix my problem, but this reset did. Hope this info helps someone else.