How to unlock Bootloader on Sony Xperia Z Ultra

How to unlock Bootloader on Sony Xperia Z Ultra

Bootloader is a little program that runs on your phone when power up , Actually  locked bootloader is  a factory restriction. If you want customize your phone by  installing custom kernel, Flashing Custom Rom , Flashing Custom recovery or rooting then you have to unlock bootloader. in this post we will give full guide with pictures to unlock Bootloader on Sony Xperia Z Ultra.  we use Official way unlock boot loader on your phone.  as wel as we discuss errors of unlocking boot loader on below the guide.

Why Is Bootloader Locked?

Android is an open source OS but Usually android device comes with locked bootloader because manufacturers want control modifications on theirs phones.  So, they lock the bootloader on their phones. when locked bootloader, it is very impossible to Flash Custom Recovery or Custom Rom  or root as well as end up with bricks

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Can I unlock bootloader on Sony Xperia Z Ultra? 

Yes you can but you can unlock the boot loader for certain releases. So check your self.

1. Type *#*#7378423#*#* and Dial. 
2. Tap Service info” go to  “Configuration ” go to  ” Rooting Status.
3. If Boot loader unlock allowed says ” Yes” then you can follow below guide.

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Unlock Bootloader on Sony Xperia Z Ultra

Step 1,

• First, Back up your Data becuase after unlock you will lose your data
• First, you should know your iMEi Number. If you don’t know then find imei
• Download and install Sony Xperia Z Ultra USB drivers

Step 2,

• Turn on USB debugging option on your Sony phone.
• switch off your Sony Xperia Z Ultra by pressing power button

Step 3,

• Press and hold Volume up and connect Sony phone to your computer/laptop. had better use original USB data cable. 

Step 4,

• go to Sony unlock bootloader page and find your Sony Xperia Z Ultra device on the list.

• accept Terms & conditions and Submit
• then you received email from that site. and there is a link to official Site. click that link

Step 5,

• Now enter your imei number (which we told you to write down. )

• accept Terms & conditions and Submit
• next page, We will able to see your unlock code. Copy it

Step 6,

• Now download Minimal ADB Fastboot tool to your pc and install it. (Simply next next )
• launch  Minimal ADB Fastboot tool

Step 7,

After install you should be on Command window.

Step 8

• Type below Codes on that command window and press enter

     > fastboot devices

• Second code is,

     > fastboot -i 0x0fce oem unlock 0x “your unlock code”

example : – fastboot -i 0x0fce oem unlock 0x87eb234h6212g5646

My Code : fastboot -i 0x0fce oem unlock 0x66CDC81676D7788B

If your Sony Xperia Z Ultra is successfully unlocked then command window says finished

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 I can’t unlock bootloader on Sony Xperia Z Ultra because it FAILED.

40/044/2016 14:35:34 – INFO – Device connected in fastboot mode
40/044/2016 14:35:34 – INFO – Unlocking phone using key XXXXXXXXXXXXXXXXXX
40/044/2016 14:35:35 – INFO – …
40/044/2016 14:35:34 – INFO – FAILED (remote: Command did not succeed)
40/044/2016 14:35:36 – INFO – finished. total time: 0.036s

A : 

1. are you sure whether you install drivers properly? please uninstall and reinstall.
2. as wel as you phone must be on booted in fastboot.
3.  may be your phone is already unlocked 
4. use different USB port or another computer

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command prompt says “Your phone bootloader cannot be officially unlocked” why? 

03/038/2016 12:37:18 – ERROR – Processing of loader.sin finished with errors.
03/038/2016 12:37:18 – ERROR –
03/038/2016 12:37:18 – INFO – Your phone bootloader cannot be officially unlocked
03/038/2016 12:37:18 – INFO – You can now unplug and restart your phone

A: developer.sonymobile  allow to unlock bootloder on some of device only. see the Supported device

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I can’t turn on my Sony Xperia Z Ultra.. it is automatically rebooting.. I think that its bootloop. now what?

A: thats mean, you have done some wrong, but you can fix it by installing Stock Firmware again. 

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 remote: Device is already rooted “FAILED: Root already exist”

A: If your Sony is rooted then its mean, your bootloader is already unlocked.

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Can i Lock bootloader on Sony Xperia Z Ultra again? back to a locked

A: Sony answer for that question officially. they says that you can’t lock your bootloader once you unlock it (you can’t restore bootloader so you may void the warranty of your device ) . but you can use  “Flash tool for Xperia Z Ultra” although it can’t get Sony updates..

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