SnOwbreeze 2.4 just released for iOS 4.3.1 to jailbreak iDevice. After jailbreaking with it you can unlock it with the help of Ultrasnow 1.2. The baseband which this Ultrasnow will support are: 01.59.00 / 04.26.08 / 05.11.07 / 05.12.01 / 05.13.04 / 06.15.00. But this is not compatible with 02.10.04 / 03.10.01 / 04.10.01 / 05.14.02 / 05.15.04.
For iPhone 3GS Only: How to Update iPhone 3GS to 06.15.00 Baseband for Unlock:
Step 1: First of all you will have to jailbreak your iPhone 4 or 3GS using Sn0wbreeze 2.4. Instructions for jailbreaking iOS 4.3.1 using this new version of Sn0wbreeze for iOS 4.3.1 are exactly similar to the last release. Simply follow our detailed step by step guide posted here to jailbreak iPhone 4, 3GS, iPod touch 4G / 3G and iPad running the latest iOS 4.3.1 firmware.
Step 2: Once done with the jailbreak, you can now unlock your iPhone on the supported basebands using Ultrasn0w 1.2 from Cydia. To do this:
* Start “Cydia” on your iPhone.
* Touch on “Manage” tab on the bottom.
* Now touch on “Sources”.
* Touch on “Edit” and then on “Add”. You will be prompted to enter a url source as seen in the screenshot below. Type “http://repo666.ultrasn0w.com” and touch on“Add Source” to add this repo if you haven’t already.
Cydia will now automatically update your sources by following a series of automated steps.
* After installation is completed. Search for “ultrasn0w 1.2” in Cydia and install this application. This app will automatically unlock your iPhone so that you can use it with any carrier.
Step 3: Now simply restart your iPhone and voila! you should now have a fully unlocked iPhone 4 or 3GS, running iOS 4.3.1 !