Unlock iPhone 4 & iPhone 3GS on iOS 4.3.1 with Ultrasn0w 1.2

After jailbreaking your iPhone 4 or iPhone 3GS using Sn0wbreeze 2.4b1, you can unlock your iPhone on iOS 4.3.1 using Ultrasn0w 1.2. For those who don’t know, Ultrasn0w and MobileSubstrate was broken on iOS 4.3 and iOS 4.3.1 due to Apple’s ASLR security feature but thanks to Msft.Guy (@msft_guy) who made Ultrasn0w Fixer for iOS 4.3 GM open-source which led DjayB6 (@DjayB6) and iH8sn0w (@iH8sn0w) to port it to iOS 4.3 and iOS 4.3.1 final version.

Unlocked iPhone 4

Supported Basebands:

  • iPhone OS 3.0 » 04.26.08 » iPhone 3GS
  • iPhone OS 3.1 » 05.11.07 » iPhone 3GS
  • iPhone OS 3.1.2 » 05.11.07 » iPhone 3GS
  • iPhone OS 3.1.3 » 05.12.01 » iPhone 3GS
  • iOS 4.0 » 05.13.04 » iPhone 3GS
  • iOS 4.1 » 01.59.00 » iPhone 4
  • iOS 4.0.1 » 05.13.04 » iPhone 3GS
  • iOS 4.0.1 » 01.59.00 » iPhone 4
  • iOS 4.0.2 » 05.13.04 » iPhone 3GS
  • iOS 4.0.2 » 01.59.00 » iPhone 4
  • iOS 4.1 » 05.14.02 via 06.15.00 » iPhone 3GS
  • iOS 4.2 » 05.15.04 via 06.15.00 » iPhone 3GS
  • iOS 4.3 » 05.16.01 via 06.15.00 » iPhone 3GS [How-To]
  • iOS 4.3.1 » 05.16.02 via 06.15.00 » iPhone 3GS [How-To]

Unsupported Basebands:

  • iOS 4.1 » 02.10.04 » iPhone 4
  • iOS 4.2 » 03.10.01 » iPhone 4
  • iOS 4.2.1 » 03.10.01 » iPhone 4
  • iOS 4.3 » 04.10.01 » iPhone 4

Steps to Unlock iPhone 4 & iPhone 3GS on iOS 4.3.1:

  1. Open Cydia on your jailbroken iPhone.
  2. Cydia 1.1 (Home)

  3. Tap on the Manage tab at the bottom of Cydia. You will see three sections i-e Packages, Sources & Storage. Choose Sources sections to add Ultrasn0w source.
  4. Cydia (Sources Section)

  5. If Ultrasn0w repo is already added to your Cydia, jump to step 6 otherwise continue to step 4 below.
  6. Cydia (Without Ultrasn0w)

  7. Click on Edit button at the top-right and then click on Add button on the top-left. Enter http://repo666.ultrasn0w.com as Cydia/APT URL and click on Add Source button.
  8. Ultrasn0w Repository

  9. Let Cydia to add Ultrasn0w repo to your current Cydia sources. Once done, click on the Return to Cydia button to get back to Sources section. Tap on the repo name and then tap on Ultrasn0w tool.
  10. Cydia (Updating Sources)

  11. Now you will see Ultrasn0w repo in your Sources section.
  12. Ultrasn0w Repo Added

  13. Click on Install button on the top-right to install Ultrasn0w tool.
  14. Install Ultrasn0w 1.2

  15. Once Ultrasn0w tool has been installed, click on Restart Springboard button and your iPhone should catch your carrier signals automatically.
  16. Restart Springboard

Note: If your iPhone fails to pick signals after installing Ultrasn0w 1.2, reboot your iPhone after restarting Springboard. The trick worked for me!

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  • Guilherme

    Hello, I have an iphone 3GS IOS 4.3.3(8J2) bb 06.15.00 with the redsn0w 1.2.5 and I get no signal. It recognize the chip but don’t get any signal. Any idea of what can I do??? Plz.
    Thanks very much in advance

    • Patrick


      Have you installed latest version of Ultrasn0w? If yes then your SIM card could have been blocked by your carrier. If you go to Settings -> Phone and see SIM Applications then it means your iPhone is unlocked. Also try to put the SIM card of some other carrier and see if it works. Last but not the least, rejailbreak if u have SHSH blobs saved.

  • Anish

    i want to unlock iphone 3G i have baseband 5.15.04 n version 4.2.1 and i have jailbreak it by useing redsn0w but dont know how to unlock it u seen pretty smart can ya help me!!!to unlock this iphone pliz n i also have cydia in the iphone 2 so any ideas you got to unlock this pliz n thnx 2

    • Pramod

      Since your on BB 05.15.04, this cannot be unlocked as of now. So you’ll need to do is update your BB to an iPad’s BB and then unlock it. All you need to do is to tick the Install iPad BB option from Redsn0w and re-run the process. Follow this guide: http://bit.ly/lccwoE
      Make sure that you DO NOT tick Install Cydia as you are already jailbroken.

  • Mark

    After my old 3GS got a bit wet and locked into a reset loop, I upgraded it from a 3.something version that was successfully unlocked, to 4.3.3. This unknowingly also upgraded the baseband to 05.16.02. After several tries with redsn0w to give it an unlocked IPSW, I used sn0wbreeze, which upgraded the baseband to the iPad baseband, 06.15.00. A problem throughout though, has been that I can’t load Ultrasn0w onto it, because the Wi-Fi setting is grayed out and unavailable. Without Wi-Fi, no Cydia store, etc. I tried using Ultra Pusher, but that didn’t work (crashes every time). Any suggestions on how to get back Wi-Fi? Or does this sound like a hardware problem as a result of the moisture?

    • Wolverine

      Yes, its a hardware issue with the baseband chip of your iPhone. As Wifi and Bluetooth are a part of baseband chip, so they wont work until bb chip get replaced. However some people *luckily* managed to escape this issue by hard-resetting their iPhone. Anyways, if you wan to install Ultrasn0w 1.2.3 without Wifi, use this guide http://bit.ly/mEpZ8z

      • Mark

        The guide didn’t work, as I had the same problems as many others: not installing, not checked in Cydia, etc, even after installing your other .debs. I cannot get into verbose mode, because I can’t install SSH stuff through Cydia (no Wifi), plus I doubt I’d know what to do with a verbose mode when I got there anyway. I really just want to get the phone working as a phone, at least until I can get the bb chip replaced (is that even possible?) So if I can get the unlock working, it would be a miracle.

        • Wolverine

          Download OpenSSH.DEB http://www.mediafire.com/?yngjlqdiqhi and place it in AutoInstall directory. You do not have Wifi? Use SSH tunnel http://bit.ly/gzY37I Once you got terminal access, place Ultrasn0w DEB in AutoInstall directory and use the following commands at terminal:
          dpkg -i /var/root/Media/Cydia/AutoInstall/ultrasn0w.deb

          • Mark

            I loaded Openssh.deb into the autoinstall directory, and then later afc2add.deb, and they both show up in Cydia as unchecked, like the ultrasn0w.deb file. So this seems to be a problem with Cydia not actually installing anything, and until that’s solved, or the chip gets fixed, it might just be truly cut off.

          • Wolverine

            I will personally recommend you to find a free Wifi hotspot near your home and install Ultrasn0w directly using Cydia. If your laptop has a Wifi card, create an ad-hoc connection to share your internet connection over Wifi. Btw, have you tried SSH tunnel http://bit.ly/gzY37I (Even if OpenSSH and Afc2add is not checked -> Ignore it for time being)

  • Dj4man

    Also, When i tried to install ultrasn0w the first time and when i uninstalled it i got a message saying COULD NOT ACTIVATE CELLULAR DATA NETWORK

    Ultrasn0w is only 14.4Kb in size. Is that a bit too small for an unlock file??

    I have re-installed ultrasn0w, ensuring ENABLE 3G was off. I didnt press RESTART SPRINGBOARD. I just held power button until SLIDE TO POWER OFF came on and turned it off that way to reboot.


    • Wolverine

      The size of Ultrasn0w is fine. Just read the reply to the above comment of urz.

  • Dj4man


    I have followed the guide and jailbroke the phone and updated the BB to 06.15 and installed Ultrasn0w 1.2.3 and still dont have any signal. Just says NO SERVICE. the iPhone said this before doing the jailbreak, hence why I want to unlock it!

    I have even manually added the DEB file via iPhone Explorer. Not working with O2 or Orange.

    Under Settings:General:About It does show which sim I have in under Carrier (O2 10.0 or Orange) But yet under Network it always shows Not Available?!?!

    Is the phone goosed? It have made one good 3GS out of 2 broken ones.

    • Wolverine

      As far as i know, there could be 6 possibilities:

      1. You upgraded the baseband of your factory unlocked iPhone 3GS
      2. You selected the wrong bootrom version while upgrading your bb to iPad bb
      3. When you installed Ultrasn0w, “Enable 3G” option in Settings app was turn ON
      4. You never rebooted your iPhone after installing Ultrasn0w
      5. You upgraded Cydia before installing Ultrasn0w (Ultrasn0w should be the first one which should be installed) (Worked for many)
      6. This tip is stupid one (as Redsn0w 0.9.6RC16 JB is untethered) but some people reported that after booting into tethered mode (Using Redsn0w), they managed to get rid of this issue.

      • Dj4man

        1. The phone wouldn’t accept Orange before doing any jailbreak on it.

        2. This handset does have the newer bootrom.

        3. I think Enable 3G was on when I installed ultrasn0w.

        4. I have rebooted handset many times.

        5. Cydia was put on the handset by Redsn0w. How can I put ultrasn0w on without cydia

        6. Does that mean using Redsnow again to jailbreak the handset but only selecting the Tethered boot option??



        • Wolverine

          According to this dude http://bit.ly/kICsCd Diptup, he tried to install Ultrasn0w offline and it never worked for him. So he installed over Wifi and it worked like a charm.

          According to this dude http://bit.ly/lMW5Ay Ulhas Dhuri, he can only clamp to network when Enable 3G option is OFF.

          I am trying to gather some facts why this problem is happening to so many people…

          • Dj4man

            Just moved house and finally got the net back on. Any further joy with any searching Wolverine?

            Really want to use this handset but cant. :-(



          • Pramod

            As of now, Ultrasn0w installation via Wi-Fi is the best option. Installation of UltraSn0w manually works well too but chances of working is minimal. :(

  • twinny

    just but changed the baseband, and added ultrasnow, just have no service? what can i do ?

  • vick

    hello i have an iphone 3gs version 4.3.1 and modem firmware 05.16.02 !! i wanted to unlock the phone as i already jailbreak the phone using redsnow. i tried using ultrasnow to unlock it on cydia by there was no carier and no service. wat i did was just to modify and remove the ultrasnow again. im confused and dont know wat to use to unlock the phone…. i want it simfree. can anybody with some good knowledge help???

    • Wolverine

      Follow this guide http://bit.ly/gBOM7o and upgrade your baseband 05.16.02 to iPad baseband 06.15.00 and then unlock your iPhone. You might lose your GPS functionality after upgrading your current baseband to iPad baseband.

  • Olivia


    I did as you suggested regarding the hard reset but the phone is still stuck at the apple logo. Also, I am using a mac so do you have a link where I can get iBooty fro mac?

  • john

    how about bb 05.16.02?? still need to upgrade to ipad bb?? because i didnt get the carrier signal..

    • Wolverine

      Yep John! You must upgrade to iPad baseband first to use Ultrasn0w!

      • John

        Thank you.. Is there any update in future to avoid upgrade to bb ipad?? Just wanna know

        • Wolverine

          No ETA but Dev-Team is working on a new NCK unlock method which might unlock 05.16.01 and 05.16.02 baseband along with other iPhone 4 bbs.

          • John

            Thank you…

  • Brian

    I am still confused…I have a 3GS jailbroken and unlocked on ios 4.0.1 with baseband 05.13.04. If I now use snowbreeze to upgrade to ios 4.3.1 do I also need to update the baseband to 06.15.00 in order to unlock or should I preserve the 05.13.04 baseband? Thanks in advance ^^

    • Wolverine

      No. No need to upgrade to iPad baseband. You can directly unlock your baseband through Ultrasn0w. Cheers!

  • peter yang

    What about iPhone 3GS 4.3 baseband 05.16.01? Can it be unlocked using this method? I cannot find it either in supported or unsupported list. I’m stuck with this. Help please…

    • Wolverine

      Yes you can unlock but not directly. You must upgrade your baseband to iPad baseband using this guide. I just updated by post and added both basebands in supported list. Thanks for telling.

      • peter yang

        So, I have to lost my GPS function. Too bad! Thanks so much ;)

  • AngelCos

    thanks..! xD
    Now I can rest… haha

  • AngelCos

    Hello, first.. my English is not very good.. excuse me for that!

    well.. i jailbreak and Hacktivate my 3GS with Sn0wbreeze.. i don’t have de carrier original, and can’t find one. ok

    i want to use SAM, but dont know the steps.. i try first clicking “Revert Lockdownd to Stock” in Settings>SAM.. but just sey “stockify Failed”, so, try too reinstall “stockify” but still not working.

    after i try using Redsn0w.. but just work whit OS 4.2.1.. anyway i use it.. when select the “Deactivate” option, and do the process (DFU, next, next..) apparently works.. but when it ends and reboot, the iphone stay always on apple screen.

    my question is: is there any way to work SAM whit sn0wbreeze on OS 4.3.1?

    • Wolverine

      SAM is broken on iOS 4.3 and iOS 4.3.1 due to Apple ASLR security feature. Hope it will be fixed soon by iH8sn0w. Stay tuned.