iPhone Dev-Team has just released redsn0w 0.9.6RC9 untethered jailbreak for iOS 4.3.1 along with PwnageTool 4.3. This PwnageTool can jailbreak iOS 4.3.1 on iPhone 4, 3GS, iPad (1st-gen), iPod touch 4G/3G, Apple TV, and at the same time will help retain the old baseband for iPhone 4 and 3GS users so that they can unlock using the existing version of Ultrasn0w.
Jailbreak iOS 4.3.1 Untethered With PwnageTool 4.3
Step 1: Download PwnageTool 4.3 for Mac.
Step 2: Download iOS 4.3.1 firmware. Move all these files to the desktop.
Step 3: Launch PwnageTool and connect your iDevice via USB. This opens a pop-up with the copyright information, click OK to get started.
Step 4: Browse for iOS 4.3.1 firmware for your device.
Step 5: Now select “Build” to start creating custom 4.3.1 firmware file.
Step 6: PwnageTool will now create the custom .ipsw file for your iPhone, iPad or iPod touch which will be jailbroken.
Step 7: Now follow the following steps to enter DFU mode using PwnageTool:
* Hold Power and Home buttons for 10 seconds
* Now release the Power button but continue holding the Home button for 10 more seconds
* You device should now be in DFU mode
Step 8: Start iTunes, click on your iOS device icon from the sidebar in iTunes. Now press and hold left “alt” (option) button on Mac, or Left “Shift” button if you are on Windows on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and then release this button.
This will make iTunes prompt you to select the location for your custom firmware 4.3.1 file. Select the required custom .ipsw file that you created above, and click on “Open”.
Step 9: Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at this stage and don’t do anything silly. Just wait while iTunes installs the new firmware 4.3.1 on your iOS device. Your iOS device screen at this point will be showing a progress bar indicating installation progress. After the installation is done, your iOS device will be jailbroken on iOS 4.3.1.