Since Sony patched the root exploit on the new Jelly Bean 4.2.2 firmware (10.3.1.A.0.244) for Xperia Z, the old root method won’t work. It requires some tricks to achieve root access on the new firmware. However, for all those who have already updated their Sony Xperia Z smartphone with the latest Jellybean 4.2.2 Android OS (build number 10.3.1.A.0.244) and wish to root the device for more control over it can now root the device without much hassle.
Thanks to a simple and accessible technique by an xda-developer DooMLoRD. He discovered a method to root Xperia Z on Jelly Bean 4.2.2 firmware (10.3.1.A.0.244) and this work on both locked and unlocked bootloaders.
The trick is by using the older kernel for which the root works and then root the device and then flash back to the newer kernel. Read below guide to know how it is. This is only for Xperia Z (C6602/3) FW 10.3.1.A.0.244!
b. XperiaZ_C660X_KernelOnly_10.3.A.0.423_Generic_NL.ftf (old kernel) and XperiaZ_C660X_KernelOnly_10.3.1.A.0.244_BE.ftf (new kernel) – Download it from source here.
Warning: Keep in mind that rooting your device will void its warranty. Also, do below guide at your own risk. We’ll not take any responsibility if anything went wrong while doing this. Also, don’t forget to backup your device.
1. Download Sony flashtool into your computer and install it (download link at the end of this article).
2. After installation, navigate to C:\Flashtool\drivers folder and install “Flashtool-drivers”. Check the box of your device model and Flashmode Drivers.
3. Connect your Xperia Z to computer via USB cable.
4. Copy the downloaded XperiaZ_C660X_KernelOnly_10.3.A.0.423_Generic_NL.ftf (old kernel) and XperiaZ_C660X_KernelOnly_10.3.1.A.0.244_BE.ftf (new kernel) to flashtool/firmwares folder in your computer.
5. On Flashtool, click the lightning icon and click flashmode, then “ok”. You should see a new window.
6. On the right pane, check “Data, Cache and Appslog” boxes if you wish to wipe the device before flash, otherwise leave it unchecked.
7. Now, at source folder, browse and select the old kernel “XperiaZ_C660X_KernelOnly_10.3.A.0.423_Generic_NL.ftf ” in the flashtool/firmwares.
8. Press flash button to start flashing and follow the instructions: 1). Unplug your device from PC, 2). Power off your device, 3). Enter to Flash Mode on your device by press and hold Volume Down button while connect your device with USB cable to computer and 4). Connect your device back to computer with USB cable.
9. Wait until the flash process to complete. You should see “Flashing finished” from the flashtool. Reboot your device.
10. On computer, close the flashtool (this is very important!) and connect your device to computer in USB debugging mode.
11. Extract the downloaded DooMLoRD_Easy-Rooting-Toolkit_v18_perf-event-exploit.zip into a new folder on your PC.
12. Double click on the “runme_file” in the extracted folder in Step 11. This will root your device.
13. After rooting, repeat steps 5 – 9 using XperiaZ_C660X_KernelOnly_10.3.1.A.0.244_BE.ftf. These steps will flash back the stock 10.3.1.A.0.244 kernel to your device.
Finally, download a root checker and check your device’s root status.