How to unlock your iPhone 4 running on iOS 4.1 using ultrasn0w

As you may well know, it is not possible right now to unlock your iPhone running stock iOS 4.1 unless you have upgraded from 4.0 using the Pwnagetool. To unlock a phone means to remove it’s carrier restriction. Unlocking is technically reversible so you don’t have to worry about voiding your warranty too much. If your phones start acting weird you can restore it through iTunes and send it to be repaired, but only if you actually can restore it, that is, if it works to the point that it can be restored. Legally, you can unlock your phone, it is not protected under the DMCA agreement but it can void your warranty if the seller finds out. Also important to note is the fact that some carriers have no problem with unlocking, to be sure just call them and ask. Some even unlock the phones themselves for a fee.

This tutorial is only for iPhones running on a cooked 4.1 firmware. Why can’t you unlock your phone you may ask? Well, if you update to iOS 4.1 using iTunes it will update your baseband as well, thus making it impossible to unlock. The baseband is essentially the modem firmware that your iPhone uses to connect with the antennas owned by the carrier. It would seem that the carriers purposely mess with the Baseband version to keep their clients from unlocking their iPhones and switching to a different mobile service provider. But don’t stress out, you can unlock it but you have to do one extra thing, which is updating the phone’s firmware using a program called PwnageTool which will update the firmware without updating the firmware. Click here for a complete tutorial on how to do that. 

 

Note: While this is not mandatory or required it would be good if you can sync and backup your iPhone with iTunes to make sure you’ll save all your important data (photos, music, documents, settings and contacts)

Step 1. Make sure that you are running the correct cooked 4.1 firmware. If you do not know how to create a cooked firmware please click here.

Step 2. Once you are sure that you meet the special requirement posted in step 1, you need to launch Cydia

Step 3. Now that Cydia is up and running do a search for Ultrasn0w and install it. But make sure the version is 1.1-1. If the version is different you just need to refresh Cydia’s sources.

Step 3. The last step is rebooting your phone. After it’s done rebooting you should have an unlocked iPhone running iOS 4.1 firmware!

 

Feel free to comment if you have a problem, the crew at iOSdoc.com will make sure that you’re voice will not go unheard.