Update Galaxy S3 GT-I9300T to Android 4.1.2 TDUEMJ1 Official Firmware

There’s a new way you can enjoy your Galaxy S3 GT-I9300T: by updating it to Android 4.1.2. This procedure and how to perform it are shown in today’s guide.

By upgrading your smartphone, released in May 2012, you will get to enjoy the full benefits of an official firmware called TDUEMJ1. This tool was launched this November for users of this handset living in the following two countries: Australia (Telstra carrier) and New Zealand.

While the firmware meant for the first country comes with an activated KIES, the one for New Zealand doesn’t have its KIES activated. In other words: if you live in Australia you can update your phone via Samsung’s KIES, but you can’t do that if you live in the other country.

You can update your smartphone without bricking it even you run a custom ROM. Our tutorial is aimed at all of our readers who don’t want to upgrade their device via OTA or KIES.

But we must warn you beforehand that this update will have an impact on your smartphone if the latter’s been rooted: the root access will be revoked and the system partition will get erased; however, the internal and external SD cards will not end up damaged. The most important data on your handset will avoid being deleted.

Here is what the new firmware brings to your Galaxy S3 I9300T: Google Now, mini applications, sync and connect email updates, all share, touch anticipation and free style widget, group cast, a new keyboard, pop up play, extended vsync timing, a fixed frame of 60 fps, triple buffering and automatic adjustment for the size of widgets.


Everything you need to know to prepare your phone for the update is delivered below:

  • locate USB Debugging and turn it on;
  • download from this page and flash, on either your laptop or PC, USB drivers for your smartphone;
  • should your phone’s battery status tell you that you must charge your battery, do it;
  • make a couple of backups (a full NANDroid one, too, via this guide);
  • make sure you disable, on your handset and laptop, the software that protects the 2 devices against security problems;
  • download the Jelly Bean 4.1.2 TDUEMJ1 (the Australia Telstra version and the New Zealand version ) and Odin;
  • your PC or laptop must run only Windows as it operating system.Galaxy-S3-GT-I9300T


  1. After the files have been downloaded where we told you to download them, you should unzip them both and then press and simultaneously hold the following buttons to enter in Download Mode: Power + Home + Volume down.
  2. Now find the Odin. After you locate it, you have to open it as Admin on your notebook or comp. What should come next is this: plug the S3 to the laptop via the phone’s USB cable.
  3. If the devices don’t encounter a successful connection, meaning you don’t see an ID:COM box in yellow and an “Added!!” message, you need to install those USB drivers one more time or use a another USB port. Then tap PDA and opt for a file which has CODE in the name.
  4. Now you should tap Phone, opt for a file with MODEM in the name and then tap CSC. When done, choose a file with CSC in its name, click on PIT and opt for a file which should feature .pit in the name.
  5. The time to begin the flashing of the new firmware is drawing near. But first, activate F. Reset Time, Auto Reboot and Re-partition. Now is the time to commence the installation we mentioned, so tap “Start“.
  6. The flashing will take a couple of minutes to end, so wait a bit. Any moment now, your Galaxy S3 I9300T will reboot. In a couple of seconds, your smartphone’s screen will show “Pass“.
  7. [sc name=”banner-jos”]You need to end the tutorial by disconnecting the Samsung I9300T from your laptop. To fully enjoy the goodies that come with the Android 4.1.2 TDUEMJ1, you have to go to it by tapping Settings, looking for About Phone and then selecting this option. And that’s it!

Is the new firmware disappointing and you want to have the old one restored? You can do that by using the NANDroid backup which is going to revoke the upgrade process.

If you don’t like something about the way the procedure went or you have trouble performing our steps, you can leave a comment below.