How To Unlock iPhone 4 On iOS 4.3.1 With UltraSn0w

Snw0breeze 2.4 now supports ultraSn0w unlock for the iPhone 4 and 3GS users (for old basebands only). Those of you who have jailbroken your iPhone 4 and 3GS (old basebands only) on the iOS 4.3.1 using Sn0wbreeze 2.4 and are dependent on an unlock can now use ultraSn0w to unlock their device on this latest firmware thus being able to use any desired carrier.

Follow the below mentioned instructions in order to unlock and jailbreak your iPhone 4 and 3GS running on the iOS 4.3.1

Points to be noted before proceeding further with the guide :

  • Sn0wbreeze 2.4 supports ultraSn0w unlock for basebands (01.59.00 / 04.26.08 / 05.11.07 / 05.12.01 / 05.13.04 / 06.15.00).
  • ultraSnow has no compatibility with the following bands (02.10.04 / 03.10.01 / 04.10.01 / 05.14.02 / 05.15.04).
  • iPhone 3GS users will now be able to upgrade to 06.15.00 under the Unlocks section in Expert.
  • You may loose your GPS if you upgrade your iPhone 3GS baseband to the 06.15.00 iPad basband.
  • If your iPhone relies on an unlock then please do not update to the stock iOS 4.3.1 yet as there is no unlock available for it.
  • Sn0wbreeze is a tethered iOS 4.3.1 jailbreak for the iPhone, iPad and the iPod Touch.

How to update iPhone 3GS to 06.15.00 baseband for unlock :

Unlocking your iPhone 3GS using ultraSn0w 1.2 requires it to be jailbroken with 06.15.00 baseband. A complete guide is available here (with PwnageTool) and here (for Redsn0w) to upgrade your iPhone 3GS baseband to 06.15.00 and jailbreak it on the iOS 4.1 or 4.2.1 before you begin following the below mentioned steps.

Step 1 :

  • Jailbreak your iPhone 4 / 3GS using Sn0wbreeze  2.4 .
  • Detailed step by step instructions are available here in order to jailbreak the iPhone 4, 3GS, iPod Touch 4G / 3G and the iPad running the latest iOS 4.3.1 firmware.

Step 2 :

On completion of the jailbreak process, you can now unlock your device on supported basebands using ultraSn0w 1.2 from Cydia :

  • Start Cydia on your iPhone.
  • Now touch on Manage tab located at the bottom.
  • Next, touch on Sources.
  • Touch on Edit and then Add.
  • On being prompted to enter a url source, enter the following : http://repo666.ultrasn0w.com
  • Now touch on Add Source.
  • Cydia will automatically update all your sources by performing a series of automated steps.
  • Once the installation is over, search for ultraSn0w 1.2 in Cydia and install the application.
  • The application works automatically to unlock your iPhone so that you can use it on any carrier of your choice.

Step 3 :

Just perform a restart on your iPhone and that’s it. You now have a fully unlocked iPhone 4 / 3GS.