As we have untethered iOS 5.1.1 jailbreak now, we can safely upgrade our iPhone 4 GSM and iPhone 3GS to iOS 5.1.1 and then unlock it using this method. This guide requires two tools, one is called Sn0wbreeze and another is Ultrasn0w. However, ultrasn0w is not updated yet to support iOS 5.1.1. For this purpose we will use an Ultrasn0w fixer.
Requirements:
- iPhone 4 with baseband 01.59.00
- iPhone 3GS with baseband 05.11.07, 05.12.01, 05.13.04 and iPad baseband 06.15.00
- Sn0wbreeze 2.9.5
- Ultrasn0w
- Ultrasn0w Fixer for iOS 5.1.1
Note: This guide is not compatible with iPhone 4S because there is no tool available which can preserve the baseband of this phone.
Part One – Installing the Custom Firmware with Preserved Basedband on iPhone
The first part of iOS 5.1.1 unlock for iPhone 3GS and iPhone 4 involves the installing of custom iOS 5.1.1 firmware having preserved baseband. Because we want to use a SIM from unofficial carrier, we will also hacktivate the firmware during this process. To accomplish the first part, we will use the latest version of Sn0wbreeze.
Step 1: First of all download iOS 5.1.1 for iPhone 4 and iPhone 3GS. This is an optional step but it is better to save the iPSW on your local hard disk.
Step 2: Download Sn0wbreeze 2.9.5.
Step 3: Unzip Snowbreeze and launch it.
Step 4: If you have already downloaded iOS 5.1.1, browse to the location where you saved it or download the iPSW file.
Step 5: Ater sn0wbreeze identifies the iPSW file, click Next button.
Step 6: If you want to preserve the baseband only but don’t want to jailbreak and add cydia to it, select the “Baseband Preservation Mode”, otherwise select the “Simple Mode”.
Step 7: At this stage it will ask you whether you want to hacktivate or not. Select “Yes” because we want to use the SIM card from unofficial carrier.
Step 8: Sn0wbreeze will build the custom firmware for you.
After Snowbreeze has created the custom firmware, use the “iREB” menu from the top of Snowbreeze to put your device into pwned DFU mode.
Once your device is in Pwned DFU mode, launch iTunes to restore this custom firmware on your iPhone.
Part 2 – Installing Ultrasn0w from Cydia to Unlock iOS 5.1.1
Because the official Ultrasn0w doesn’t support iOS 5.1.1 yet, so first we’ll have to install the Ultrasn0w fixer iOS 5.1.1 and then install the actual Ultrasn0w.
Step 1: After you have restored custom iOS 5.1.1 on your device, launch Cydia and add the following repo “http://repo.iparelhos.com/” by going to Manage -> Sources -> Edit -> Add.
Step 2: Search for Ultrasn0w fixer for 5.1.1 and install it.
Step 3: Now search for Ultrasn0w and install it too.
Step 4: Reboot your device.
Your device is not now unlocked on iOS 5.1.1 along with untethered jailbreak on your device.
This worked great for me!!! IPhone 3Gs Thank you very much!!!
Unknown error occured 1600. how to fix this??
thanks..
Possible reasons:
1) The device was not in pwned dfu mode before the restore process. Re-run iREB and try again. You can also download the separate iREB app from iH8sn0w for this purpose.
2) Have you ever downgraded the iOS using this PC which you using right now? If yes, please check the hosts file and make it sure there is no entry for Cydia server. The best solution for this problem is to use another PC/Mac where you never used TinyUmbrella and didn’t change the Hosts file. After preparing the custom iOS file and putting your device into pwned DFU mode, you can use Mac machine to restore it.
3) The USB on your PC which you are using to connect your device was PC is not real 2.0 USB. Try another usb port on your PC.
Sorry, a typo-error. I have corrected it.
What do you mean about this statement on your last post?
“Your device is not unlocked on iOS 5.1.1 along with untethered jailbreak on your device.”
Do you mean that even if we install ultrasnow on our iphone it will remain lock?