Jailbreak iPhone iOS 4.3.1 with PwnageTool

PwnageTool 4.3 provides an untethered jailbreak for iPhone 3GS, iPhone 4 GSM, iPod Touch 4G, iPod touch 3G, iPad, and Apple TV 2, all running iOS 4.3.1.

This guide is geared towards jailbreaking iOS 4.3.1 on iPhone 4 and iPhone 3GS because PwnageTool is able to preserve baseband for iPhone carrier unlocks. If you are simply looking for a jailbreak and do not need to use an unlock, you will find jailbreaking iOS 4.3.1 using redsn0w is easier.

How to Jailbreak iOS 4.3.1 using PwnageTool

PwnageTool 4.3 allows you to jailbreak iOS 4.3.1 while preserving unlocked iPhone baseband. This guide assumes you have not upgraded the iPhone to iOS 4.3.1 yet:

1. Download PwnageTool 4.3
2. Download iOS 4.3.1 firmware
3. Launch PwnageTool 4.3
4. Select the “Expert mode” button at the top
5. Select “iPhone” from the PwnageTool menu
6. Click the Next button, then browse and select the iOS 4.3.1 firmware you downloaded earlier, click Next again
7. Click on “General”
8. Important for unlockers: Check “Activate the phone” if you rely on iPhone unlock, this is not necessary for official carrier use
9. For now, ignore the Cydia package installations and click next
10. From “Custom package settings” select to install “Cydia” by checking it, click next, then click “Build” to create a custom IPSW file
11. Save this custom IPSW file to your desktop or another place you can easily find it, this is what you will restore to for jailbreaking your iPhone
12. After the custom IPSW is built, you will be asked to connect your iPhone to the computer to enter into DFU mode
13. Plug in your iPhone and follow the instructions for DFU mode: Hold Power + Home for 10 seconds, release power but continue to hold Home for 10 seconds. PwnageTool will notify you when it has detected your iPhone in DFU mode
14. Now launch iTunes
15. iTunes will notify you that it has detected an iPhone in recovery mode. Option click on the “Restore” button within iTunes to bring up the firmware restoration option
16. Select the custom IPSW file that you created with PwnageTool
17. iTunes will now restore the iPhone to the PwnageTool jailbroken IPSW firmware, this may take a few minutes

When iTunes is finished, the iPhone will boot into a jailbroken iOS 4.3.1. You can verify the jailbreak worked by looking the Cydia icon on your iOS homescreen.

If you completed the jailbreak properly, your baseband will also have been preserved allowing you to unlock iPhone 4 or 3GS running iOS 4.3.1 using ultrasn0w 1.2.1. Installing the ultrasn0w carrier unlock is simple, but you must have iPhone 4 or iPhone 3GS on baseband 01.59.00, 04.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00 in order to work.