Update AT&T Galaxy S6 SM-G920A to Android 5.1.1 Lollipop (G920AUCU3BOI2 Firmware)



AT&T has rolled out Android 5.1.1 Lollipop G920AUCU3BOI2 firmware for AT&T Galaxy S6 SM-G920A. In this tutorial we are here at Thunderztech.com to guide you on flashing the Android 5.1.1 Lollipop firmware on your AT&T Galaxy S6 SM-G920A. The Android 5.1.1 Lollipop firmware comes with a variety of improvements with updates features and security issue fixed. The G920AUCU3BOI2 firmware is based on Android 5.1.1 Lollipop and it is a security update so it is always recommended to keep your Android device updated with the latest firmware.

You can easily update your AT&T Galaxy S6 to Android 5.1.1 Lollipop OI2 firmware by following our step by step instructions. This is not the first update released for AT&T Galaxy S6 but many other Samsung’s Galaxy devices have already updated to latest firmware. Below you can find information about your device model number and the firmware information, just keep scrolling down.


G920AUCU3BOI2 firmware details:

Model Name: AT&T Galaxy S6
Version: Android 5.1.1 Lollipop

Samsung Galaxy devices can be updated to newer firmware by three different software update methods. You can follow any one of them you find easy but every firmware update process has some limitations and requirements. If you have installed custom recovery on your device it will be replaced by the Stock Recovery image and your device will become completely Stock after flashing the firmware. Below are the three firmware update methods you can follow to update your AT&T Galaxy S6 SM-G920A.

How to update AT&T Galaxy S6 SM-G920A on Android 5.1.1 lollipop via OTA (Over The Air) method

This is the first and preferably the most easiest method to update your AT&T Galaxy S6 SM-G920A to G920AUCU3BOI2 firmware. You can use your device to download the firmware file if available and then the device will ask you to install the updates now or later. As we mentioned above the limitation of OTA method is that you can update your device to latest firmware only as long as you are present inside the region where the OTA has landed and your device is in stock un-rooted condition because rooted device will not able to receive the OTA updates then you have to un-root your device or switch to the alternative methods like Kies or Odin. To check whether your device is eligible for OTA Firmware update, unlock your device & navigate to

Settings >> About device >> Software update >> Check for updates

This will require a working internet connection to connect to the Samsung servers. You will receive a notification about the latest firmware availability click install to flash the firmware or tap install later to flash the latest update anytime later.

How to update AT&T Galaxy S6 SM-G920A on Android 5.1.1 Lollipop via Samsung Kies

Samsung Kies is another useful firmware update application for Samsung and a bit easier to use, just follow the below steps to update your AT&T Galaxy S6 SM-G920A to G920AUCU3BOI2 firmware using Samsung Kies.

  • Download the Samsung Kies application from the Samsung website and install it on your windows PC or Mac.
  • Once the installation process completes, click the Kies icon to run the application.
  • Now connect your device to the PC using USB data cable.
  • You device will be automatically detected by Kies application and now you can perform multiple functions apart from the firmware update. The Kies application allows you to create a backup of your device before updating to new firmware, click the “Backup and Restore” button and follow the on screen instructions.
  • Once you successfully created a back up of your device now you can update your device to latest available firmware.
  • Click the Firmware Upgrade button to check whether new firmware is available for your device, if the firmware is available for your device you will be notified.
  • Proceed further and follow onscreen instructions to start the Update process.
  • Your device will reboot automatically once the process is completed.

If this process doesn’t helped you, proceed further to manually update your AT&T Galaxy S6 SM-G920A to latest firmware via Odin. Odin is a third party tool use to update the device firmware, this is a manual way to update the device firmware if the above two methods doesn’t work for you.

How to update AT&T Galaxy S6 SM-G920A on Android 5.1.1 Lollipop manually using Odin

To update your AT&T Galaxy S6 SM-G920A via Odin tools you need to download necessary files which you are going to use in the update process.


Download and Extract Odin 3.10.6

Download Samsung USB drivers

Before you Begin:

Disclaimer: This tutorial includes multiple operations which include flashing Stock Firmware, Custom ROM, Custom recovery and rooting. Follow the guide on your own risk, we are not responsible if you brick or damage your device however the chances of bricking a device are rare but you have to pay full attention on the complete guide to avoid any issues and difficulties while performing any of the above mentioned operation.

Please ensure your phone battery should be charged at minimum 60%

Enable USB Debugging, go to Settings >> Developer Options >> USB debugging

Note: If you can’t see Developer Options on your device setting’s menu then you have to perform an extra step, go to Settings >> About device >> Navigate downward till you see an option “Build number” Tap it seven time quickly until it says “you are now a developer” . This will enable Developers Options on your device in the Settings menu now go back and enable USB debugging as described in the above step.

Download and Extract G920AUCU3BOI2 firmware file from the below provided links.

Download G920AUCU3BOI2 Android 5.1.1 Lollipop firmware

Process to update your AT&T Galaxy S6 SM-G920A to Android 5.1.1 Lollipop G920AUCU3BOI2 firmware

If you are new to this tool then you have to pay attention on the step by step sequence to avoid any mishap during the update process.

  • Click Odin.exe to run the Odin tool.
  • Now boot your device into Download Mode by turning off your device properly and turn it on again by pressing and holding Home Button+Volume Down +Power Key simultaneously until you see a warning now press Volume up to enter Download Mode.
  • Connect your device to PC via USB cable.
  • If you have properly installed USB drivers on your PC, Odin will detect your device and the ID:COM box should turn blue which indicates that your device has been successfully added.


  • Please make sure “Auto Reboot & F.Reset Time” options are checked in the Options Tab on Odin screen.
  • Now click the AP tab and select the firmware TAR file that you have downloaded and extracted earlier.
  • Hit the start button at the bottom and wait for the installation process to complete.


  • Once the firmware update process is completed you will see a “PASS” message in the ID:COM box (as shown).
  • Your device will automatically reboot with the newly flashed firmware.

What to do if your device stuck in boot animation longer then usual

This is an optional method if your device is taking longer and won’t boot and stuck on the Samsung logo for the duration of more then 10-15 minutes. This is bootloop or soft brick, you can perform the below described 2 steps to fix the bootloop. However the chances of getting softbrick are rare after flashing Stock Firmware.

  • Pull the battery out from your device and re-install it.
  • Now boot your device into stock recovery mode by pressing and holding the volume up+Home+power buttons simultaneously.
  • Once your device boot into recovery mode, from the main menu select Wipe Data/Factory Reset and Wipe
  • Cache Partition then go back and select reboot system now. (Use volume keys to navigate)

That’s it! You have successfully updated your AT&T Galaxy S6 SM-G920A to Android 5.1.1 Lollipop G920AUCU3BOI2 firmware. If you have any query feel free to contact us by posting your queries in the below provided comment section. Follow us on Facebook/Twitter/Google+ for future update.

A Software Engineer who loves to hang around latest gadgets and writes his own experiences to get the best possible and accurate information.
1 Comment
  1. Reply Marcos October 2, 2015 at 8:36 pm

    Hi ! Could i flash my devices. With this firmware despite my phone has diferentes letter afer de g920a ?

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