Last Updated on July 23, 2022 by Mathew Diekhake

Recently Sony rolled out a new Android 4.4.4 KitKat over the air update for the Xperia Z1, Z1 Compact and Z ultra that comes with the build number of 14.4.A.0.157. You can check out everything to know about the firmware here. We covered the release upon the first release. Once you have updated to the latest software you may be looking to gain root access. Root is the sure way to unchaining the devices system internals and opening it up so that the end-user can get the most out of the device without the default factory restrictions imposed by the manufacturer. The Japanese phone-makers always install restrictions that stop us from achieving the devices true potential. Anyway, by following just a few quick steps thanks to a guy named Waledac over at XDA, you can unlock the system internals and start installing custom ROMs and applications that are not available from the Google Play Store.

Firstly let’s run through the essentials so that you know what you need. The guide works for all smartphones that received the aforementioned firmware version OTA update. If you are running the latest software version in the title then it does work for you regardless of your devices model number. You can check the model number by navigating to the Settings > About phone > Build Number.

Android 4.4.4

Details of Note

  • You must backup the data on the phones before starting. You run the risk of losing phone contacts, settings, SMS text messages, videos, pictures, music and more unless you make copies of the data. Take advantage of applications available from the Google Play Store such as helium for Android, SMS Backup+ and Holo Backup. If you have your own personal favorite method of making copies of the data, it’s fine to follow that through. You don’t need to use the apps we are mentioning. They are purely our recommendation.
  • Check that you have enough battery power reserved before starting the steps. You will connect to a computer for some of the steps, therefore, the battery will charge up using the USB charging feature that most modern-day smartphones have. Nevertheless the last thing you can afford to have happen is the phone shutting down from a lack of battery power before the flashing finishes. If the phone shuts down during the guide it can soft-brick the device. Check you have enough power before starting by observing the battery stats icon from the status bar. You want to have at least 50% power.
  • The steps are for advanced Android users only. Don’t try to unlock the system internals unless you know what you are doing. You will void the manufacturer’s warranty by following it through. The only way the remaining warranty works again is if you flash the stock software over the top again.
  • Do not install future OTA updates with root access. Doing so always risks bricking the handset. You want to wait for the file to become available and flash the file manually. Even if you notice future software updates arriving as a notification over the air, you don’t want to confirm and install them. Phone carriers and device manufacturers have little interest in making it safe for you to flash OTA’s over root access since they don’t want  you unchaining the operating system. Don’t let it turn you off since it’s simple to fix by installing manually.
  • You must turn the phone on and enable USB Debugging Mode from the Developer Options menu. The menu is not hidden in KitKat so you’ll have no trouble locating it from the Settings menu. Earliers version of Android 4.2 Jelly Bean had the menu hidden. Users had to unlock it by tapping on the build number seven times. As fun as that was, they quickly got rid of it since it was causing far too much stress from people desperately attempting to enable USB Debugging.
  • Make sure you are running the firmware version mentioned in this post.

How to root the 14.4.A.0.157 firmware on Sony Xperia Devices

1. Download the following files onto your computer:

2. Download the Sony Flashtool here.

3. Open and run the flash tool.

4. Flash the C690X_14.4.A.0.108_KernelOnly.ftf file.

5. Leave the flash tool.

6. Apply root on the phone using the rootkitXperia_20140719.zip.

7. Extract rootkitXperia_20140719.zip.

8. Install the Sony PC Companion.

9. The PC companion will install the ADB Drivers.

10. Leave the PC Companion.

11. Run the install.bat file.

12. Run the flash tool once again, only this time flash the C690X_14.4.A.0.157_KernelOnly.ftf file.

Your Sony Xperia Z Ultra or Z1 devices are now ready to have the root applications installed on it. If you’ve unlocked the bootloader, you might be able to use one of the root applications like the ROM Manager to check out some custom ROMs that can be installed. If there are any available, you won’t need a custom recovery image for that.

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