3GS Reboots 8 minutes into phone call - Replace mobilewatchdog file on iOS5 - Help?

Mar 2, 2009
I have had problems in the past on IOS 4.x.x with my iPhone 3gs randomly rebooting during phone calls. Usually this happens around 8 minutes into the call.
The Apple forums and interwebs are littered with discussions on this. The fix for me and many others was replacing the mobilewatchdog.bundle file as follows: -


For whatever reason - I don't understand - but this DEFINITELY fixes the problem.

I've been quite happy using my phone again for a good number of months having carried out this fix... until I Upgraded to IOS5

I'd forgotten all about this problem..... only to be reminded today, 8 minutes into a phone call.
I've checked by making a couple of calls since and yep - it does it every time.

The only problem is.... the file structure appears to be different under IOS5. I can't find the mobile watchdog.bundle to replace -

Has it moved?
Does it still exist?

If not... anyone else having the same trouble and know of a fix for this?
In all fairness, it's a right pain in the ass. The phone is pretty much unusable due to this.

I'd be really grateful if anyone can help with this.


Jun 21, 2010
Far from an expert here, but never heard of this problem. When you upped to iOS 5 did you set it up as a new phone?
If it is still doing it, I would do a restore as a new iPhone and see if that helps.
I hate using the "do a restore" idea, but that may be your best bet. ?


New Member
Oct 22, 2011
Hi i had the same problem and i couldnt fix it BUT i founded a way to go back to your latest iOS mine Was 4.3.3 i have an iPhone 3GS 32g and i went back to that iOS WITHOUT Ecid's because i forgot to save mine so maybe i can help u out if you wanna go back to an older version
Mar 2, 2009
Thanks for answers so far....

Restoring as new iPhone won't work. It appears to be an issue with the battery from what I can tell and the replacing of the Mobilewatchdog file used to work on 4.x.x

I don't want to downgrade back to IOS4 but have my ECIDs saved with Cydia so can do if I have to.