If you are using the Sony Xperia T2 Ultra Dual D5322 and have updated to the latest Android 5.0.2 Lollipop with firmware build root 19.3.A.0.470, you might be looking to open the system internals with root access. I’ll show you how to do that now by downgrading. Understand that this is taking you back down to stock KitKat and then created a pre-rooted flashable Lollipop firmware. It’s a long guide but at the moment there’s no shorter guide. In future you might want to look for a One-Click method.

before starting the guide I recommend you read our list of essentials for the Xperia T2 smartpohone. That way you have the T2 prepared with everything you need, you know the risks involved regarding the T2 and everything else.

Sony Xperia T2 Ultra

You should backup the current data and OS using the usual backup method you have. You can use the built-in backup feature to store data to the internal SD card. That way if you have to apply a factory reset you can do that and still have the data stored. You can also use third-party application to store other data such as call logs, SMS texts, pictures, movies, music files, Settings, phone contacts and more.

You cannot take a NANDroid backup until you have a custom recovery image installed. A NANDroid is the far easier method for taking a backup since it takes a mirror image snapshot of the ROM. You can take the NANDroid using TWRP Recovery on CWM Recovery.

Enable the USB Debugging Mode on the T2 by navigating over to the Settings > Developer Options > USB Debugging. A check in the box indicates that it is on and you don’t have to confirm that command. Once you leave the Settings it remains on automatically.

If you do not see the Developer Options menu, that usually means it needs unlocking. To unlock it you must tap the build number seven times from the About Device menu. Don’t worry, this is not changing the mode of your Xperia smartphone. It’s just unlocking a new menu that Google called “Developer Options”. It is not a special developer mode.

You must use a Windows PC and setup ADB and fastboot with Android SDK. You can check our guide for installing Android SDK and ADB and Windows.

How to root Xperia T2 Ultra Dual D5322 on Android 19.3.A.0.470 5.0.2 Lollipop

  1. Downgrade to Android 4.4.2 KitKat by downloading the FT file here.
  2. Use the Flashtool to flash the above file to your Xperia device.
  3. Unlock the bootloader if you don’t have the bootloader unlocked already.
  4. Download the TWRP Recovery you will want as your custom recovery for flashing custom ROMS later.
  5. Rename the TWRP file after you download to boot.img
  6. Transfer the boot.img over to the Fastboot folder on your PC. That’s the one you should setup along with ADB and Fastboot as part of the Android SDK guide.
  7. Completely power down the T2 smartphone by holding in the Power button for 10 seconds and then releasing.
  8. reboot the T2 in Fastboot Mode by pressing and holding the Volume Up button in while connecting the T2 to the computer with USB.
  9. Right-click the mouse and hold the Shift key in a blank white area inside the fastboot folder and select to open the command window from the new menu that’s on the screen.
  10. Type the first command and hit enter: fastboot devices
  11. Type “fastboot flash boot boot.img” and hit the enter key.
  12. Lastly, type: “fastboot reboot” after the flashing finishes and your Xperia will reboot.
  13. Download the SuperSU to the desktop of the computer.
  14. transfer that SuperSU file (zipped) to the internal SD card.
  15. Completely switch off the Xperia smartphone and reboot to recovery mode: tap the Volume Down button at the Sony boot logo after turning it on to Enter the recovery mode.
  16. Now you are inside the custom TWRP recovery and not the stock recovery. Go to the menu and tap over the “install” option and upload the SuperSU zip. Now confirm you want to install that SUperSU and wait until it’s done.
  17. Navigate back to the main recovery menu and select the Reboot > System option.
  18. Download the Dual recovery on the desktop.
  19. This time you want to extract the Dual recovery zip file on the desktop, plug your Xperia T2 into the computer and run that installer program.

Now you have downgraded and rooted that Android 4.4.2 KitKat again.

If you want to go on from there you can download the PRF Creator tool from XDA Developers and create a pre-rooted .470 FTF firmware. Now you transfer that zip file after it’s done in the PRF creator tool  over to the internal SD card of your Xperia. Make sure it’s in the root directory of the SD card. Now open the NDR Utils app to reboot your device into the custom TWRP recovery. Flash the pre-rooted firmware you created by selecting the “install” option from the main recovery menu. From there you must open the Flash tool once more and flash the 470 FTF and exclude the system only from the Flashtool options.

After you complete that you have the rooted Android 5.0.2 470 Lollipop firmware build with Dual recovery installed.