How to Unlock the Bootloader on the HTC J Butterfly (HTL21) on KDDI

The HTC J is the Japanese version for KDDI network of the Butterfly, and is a pretty packed device with a 4.3-inch display, 1.5GHz dual-core CPU coupled with 1GB RAM, an 8MP camera and running Android 4.0.4 out of the box.  All of those specs seem pretty good except for the last part, the part about it running ICS 4.0.4.  With Jelly Bean already popular, HTC could have released the device with it but they didn’t so.  So is there any other way to get to JB? Of course there is, and to do that, you’ll need to unlock your bootloader, root your device and install a custom recovery.  This guide below will show you how to get that first step out of the way – unlocking the HTC J’s bootloader!

I.  Before You Begin

1.  Charge your device to 75% or more to prevent any shutdowns during the procedure.

2.  Back up everything you feel is important before you start.

3.  You should have ADB and the necessary drivers installed before you can start.  If you haven’t already done so, use our guide on the same to help you.

4.  Following this procedure will void your warranty! If you don’t want this to happen, stop now and come back to check if there is a way to unlock your device without losing warranty.

II.  Necessary Downloads

htcj_butterfly_diaggetroot.zip [Download link available under the preparation section of this post]

III.  Unlocking the Bootloader on the HTC J

1.  Enable USB Debugging on our device.  To do this, go to Settings > Developer Options and tick the Enable USB debugging checkbox.

2.  Extract the htcj_butterfly_diaggetroot.zip file you downloaded above to your ADB folder [the folder where adb.exe is present].

3.  Open a command prompt window in this folder.  To do this (on Windows 7), hold Shift on your keyboard and right-click on the folder.  Click on Open Command Window here.

4.  Connect your device to your Windows 7 PC.

5.  Type in the following commands

adb install diaggetroot.apk [Enter key]

adb push getroot /data/local/tmp/getroot [Enter key]

adb shell chmod 777 /data/local/tmp/getroot[Enter key]

6.  On your phone, you should now find an app called BreakSuidDiag installed.  Run this app and wait for the Hello World! message.  [This will give you temporary root access]

7.  Back on the PC, run the following commands:

adb shell [Enter key]

/dev/sh [Enter key]

8.  You should now have the # symbol on your PC’s command screen and this signifies that you now have root access.  If not, turn WiFi on/off on your device and run the /dev/sh command again.

9.  Next, run the following commands:

echo -ne “11111111” | dd of=/dev/block/mmcblk0p5 bs=1 seek=20 [Enter key] {Changes the CID to 11111111}

reboot bootloader [Enter key] {Boots your device into the bootloader}

fastboot oem readcid [Enter key] {Should now display the CID as 11111111}

10.  Once you see the 11111111 on your PC, head to HTC Dev website.

11.  Follow the instructions on the HTC website to complete the unlocking process [Remember to select ALL OTHER SUPPORTED MODELS when asked to choose!]

Your HTC J should now be unlocked, enabling you to root your device and install a custom recovery, and then a custom ROM of your choice!

If this procedure helped you please thank/donate to the original developers here.

If you need help with this procedure, please ask in the comments below or in the forum.

This is part of our Android How To’s. We have how to’s on rooting, loading ROMs, and tons of other tips and tricks for your specific device or for Android devices in general! For all of our Android How To’s, head here.