If you ever need to relock the bootloader of the LG G6 or G6+, you can follow these simple steps outlined in the tutorial down below.
This week I’ve showed you how to unlock the bootloader of the LG G6, and today I want to walk you through the steps to reverse that change. This can be done because you want to return the device to LG, your wireless carrier, or the retail store you bought it from. You may want to do this simply because you plan on selling the LG G6 to someone and they don’t want the bootloader to be unlocked when they receive the device.
Whatever the reason is, the process is quite simple and you most likely already have most of the stuff setup already (meaning drivers, ADB and Fastboot tools). So we really just need to connect the LG G6 to the PC with a USB computer and then issue a special command in the Command Prompt so that it locks the bootloader again. However, I do want to say that you’ll want your LG G6 to be complete stock (as far as software is concerned).
So be sure you undo any major modifications to your device (like using a custom recovery, root access, etc), and you may even want to use special software to return the LG G6 to stock Android ahead of time.
In order to complete the tutorial below, you're going to need some things set up ahead of time. Please follow the how to install ADB and Fastboot tools guide if you haven't done so already. Then you will need to follow this guide: How to Enable Developer Mode, as well as this one which shows you How to Enable USB Debugging Mode.
You will then need to open a command prompt within the same folder as your ADB and Fastboot tools and execute the "adb devices" command (without quotes) to start the ADB service. From here, you can connect the device to the PC with a USB cable. If everything has been done properly then you'll be asked if you want to grant USB Debugging Mode access from the PC the phone is connected to.
Once granted, you can then test this by running the command "adb devices" again (without quotes) in a Command Prompt, Terminal, or Windows PowerShell to make sure the computer recognizes the device.
Note – Locking the bootloader of the LG G6 will wipe all of the user data off of your device. This is how it is on other devices and it remains the same for the LG G6. So be sure to backup as much of your information as possible before you proceed with this tutorial.
LG G6 Lock Bootloader
- Enable Developer Mode on the LG G6
- Enable OEM Unlocking on the LG G6
- Boot the LG G6 into Fastboot Mode
- Type the following command into the Command Prompt. . .
- fastboot oem lock
- . . .then press Enter on the keyboard
- Wait for the Command Prompt to tell you the process has finished
- Then type the following command into the Command Prompt. . .
- fastboot reboot
- . . .and press Enter on the keyboard to boot the LG G6 back into Android
As you can see, the process to lock the LG G6 bootloader is incredibly similar to how we unlocked the LG G6 bootloader. As noted before the step by step tutorial, you will need to have ADB and Fastboot tools installed on your PC. You’ll then need to start the ADB service, have Developer Mode and OEM Unlocking enabled on the LG G6 and make sure you grant USB Debugging access from the PC to the LG G6 so that you can issue the ADB command.
With that done, you simply need to boot the LG G6 into Fastboot Mode as described in Step 3 (click the link to go to that guide). Once you are in Fastboot Mode, we can tell the bootloader is already unlocked (since the screen is different compared to when it is locked). So we just need to execute the Fastboot OEM Lock command in the Command Prompt and just like before you should see the Command Prompt telling you that it is erasing userdata on the device.
This is required again, just like it is when you unlock the bootloader, so there isn’t a way to get around it. Be sure that you have all of your important data backed up ahead of time before you start to follow this step by step tutorial. The erase part is very quick and takes less than a few seconds. Once it is done, you should see the screen on the LG G6 revert back to how it looked when the bootloader was locked. If you see it changes back, then you know you have locked the LG G6 bootloader again and that you’re done.
So now, all you need to do is execute the Fastboot Reboot command in the Command Prompt (or press and hold the Power and Volume Down buttons for a few seconds) to force the LG G6 to reboot. This first boot cycle will take longer than normal since you just erased everything and it needs to set stuff back up for you. You’ll be booted directly into the Android activation screen where you will need to input your Google account and set all of your applications and games up again.
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