An unofficial PwnageTool version have been released to jailbreak iPhone 3GS iOS 4.1. If you have updated your device to iOS 4.1, thenJailbreak iPhone 3GS iOS 4.1 you could use this guide to jailbreak iPhone 3GS (Old Bootrom) on Mac OS X or you could downgrade to the old iOS 4/4.0.1/4.0.2 firmware then jailbreak it again.

NOTE: You would have to activate your iPhone 3GS using an officially supported SIM or the phonebook SIM card trick before you unlock the phone as hacktivation is not supported by this PwnageTool. Also you should proceed to the steps at your risk. Do the steps carefully that you don’t make any mistake.

1. Download PwnageTool from http://www.megaupload.com/?d=VZ52C0AY and the iPhone 3GS iOS 4.1 firmware from here.

2. Connect your iPhone 3GS to the computer and take a backup of it in iTunes so that you could restore back your settings later.

3. Launch PwnageTool.

4. Choose your iPhone 3GS with iOS 4.1 and go forward.

5. PwnageTool will detect the iOS 4.1 firmware. Move forward.

Jailbreak iPhone 3GS iOS 4.1

6. When PwnageTool ask you ” Do you have an iPhone contract that would activate normally through iTunes? “, click on “No” if you are not on an officially supported carrier. Click on “Yes” only if you are having an officially supported carrier on your phone like the AT&T. PwnageTool will now begin to create the IPSW file.

7. During the process, when asked to to authenticate your account, ignore that and install the ” iOS4.1Jailbreaker installer package ” which came along with the PwnageTool you downloaded earlier. Now go back to the prompt you ignored in the last step and enter the password and go forward so that PwnageTool finishes the iOS 4.1 custom firmware building process. When the process is completed, a ” ihaz Success! ” message will be shown.

8. Now open iTunes and select your iPhone 3GS in it.

9. In Windows, hold the Shift key and in Mac OS X, hold the option key and click on ” Restore “.

10. Browse to the iOS 4.1 ipsw file that PwnageTool cooked earlier and let iTunes do the rest of the iPhone 3GS iOS 4.1 jailbreak process. After the process is finished, your phone will automatically reboot and it will be jailbroken on iOS 4.1.

11. If a 1004 or 1015 error is shown, just ignore them. But if your iPhone 3GS gets stuck in Recovery Mode, then the TinyUmbrella software could help you solve this problme by escaping your iPhone from it. Download it for Windows or Mac OS X, run it and the click on “Kick Device Out of Recovery” button.

NOTE : If Cydia shows a blank white icon, then add the repo ” http://apt.saurik.com/cydia-3.7 ” in Cydia to solve it.