How To: Use CyanogenMod 12.1 To Install Android 5.1.1 Lollipop On A Samsung Galaxy S2 Plus I9105/P

Last updated: July 1, 2020.

How To Use CyanogenMod 12.1

Use CyanogenMod 12.1 To Install Android 5.1.1 Lollipop On A Samsung Galaxy S2 Plus I9105/P. Samsung released the Galaxy S2 Plus in 2013.  The Galaxy S2 Plus is a sibling of the Galaxy s2 and their specifications are not that different.  The Galaxy S2 Plus originally ran on Android 4.1.2 Jelly Bean and, since then, the device only received one official update and that was only to Android Jelly Bean 4.2.2.

Samsung usually tends to forget about updating their older mid-range devices so it doesn’t look like the Galaxy S2 Plus will be seeing an official updates any more.  If you want to update your Galaxy S2 Plus to a higher Android version, you are going to need to turn to custom ROMS.

CyanogenMod 12.1 is a great custom rom based on Android 5.1.1 Lollipop and it can be used on a Galaxy S2 Plus.  It is a good ROM with no known issues so installing it will upgrade your device without causing any harm.  In the guide below, we are going to show you how to update a Galaxy S2 Plus I91o5, I9105P to Android 5.1.1 Lollipop with the CyanogenMod 12.1 custom ROM.

Prepare your phone (CyanogenMod 12.1):

  1. This guide and the ROM we will be using is only for the Samsung Galaxy S2 Plus I9105/P. Do not try it with other devices as it could brick the device.
  2. Your phone needs to already be running Android 4.2.2. Jelly Bean. If it is not, update your phone to that first before proceeding.
  3. You will need to have a custom recovery installed. If you haven’t already, install TWRP 2.8 recovery.
  4. When custom recovery is installed, make a Nandroid backup.
  5. Charge your device so it has 60 percent of its battery life. This is to ensure that your device does not run out of power before the flashing process is over.
  6. Back up the following:
    1. Call logs
    2. Contacts
    3. SMS messages
    4. Media – copy files manually to a PC/laptop
  7. Have an EFS backup.
  8. If your device is rooted, use Titanium Backup.

Note: The methods needed to flash custom recoveries, roms and to root your phone can result in bricking your device.  Rooting your device will also void the warranty and it will no longer be eligible for free device services from manufacturers or warranty providers.  Be responsible and keep these in mind before you decide to proceed on your own responsibility.  In case a mishap occurs, we or the device manufacturers should never be held responsible.


  1. A CM file. Make sure it is compatible with your device:
  1. Gapps for CM 12



  1. Connect your phone to the PC.
  2. Copy the downloaded files to your phone storage.
  3. Disconnect your phone and turn it off.
  4. Boot you phone into TWRP recovery by turning it on by pressing the volume up, home button and power key. Keep these three pressed until the phone boots into recovery mode.
  5. In recovery, choose to wipe cache, factory data reset and go to advanced options and select dalvik cache. This will wipe all three.
  6. Select the Install option
  7. Install>Choose zip from SD card>CM>Yes.
  8. The ROM should now flash on your phone. When it is done, go back to the main menu of recovery.
  9. Repeat step 7 but this time choose the Gapps file.
  10. Gapps will flash on your phone.
  11. Reboot your device.

The first reboot could take up to 10 minutes, but it should reboot and then you will see Android 5.1.1 Lollipop running on your device.

Have you updated your Galaxy S2 Plus?

Share your experience in the comments box below.


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