Chainfire’s CF-Auto-Root tool can root the Samsung Galaxy Tab A SM-T355 tablet when it is running on the Android 5.0.2 Lollipop software updates. By rooting the Android operating system on the tablet, we are referring to becoming the root user which means having full control over what is installed and uninstalled. That includes getting the chance to remove the system apps from Samsung and your phone carrier networks.
One of the ways you can remove system apps is by installing the Titanium Backup  app. Once you grant Titanium Backup access to everything on the tablet that it needs to run, it can read all of the application’s data. It’s that ability to read that makes it powerful enough to let users backup any data that they want. The root access also means that it can get access to the system partition to remove anything that is tucked away like the system apps.
- You must have the Samsung Galaxy Tab A with the SM-T355 model number to use this guide. Flashing the CF-Auto-Root tool on the wrong model number can brick the device.
- You must have a computer that is running on a version of the Windows operating system to use this guide. The Odin flashing tool does not run unless it is running on Windows.
BEFORE WE BEGIN
- Chainfire was running on the LRX22G.T355XXU1AOK1 firmware build number when he developed the CF-Auto-Root file in this guide for the Samsung Galaxy Tab A SM-T355 tablet. You don’t need to find that firmware and run it like he did. You can run any firmware as long as you are running Android 5.0.2 Lollipop and have the SM-T355 model number.
- If you flash the CF-Auto-Root tool, and the device does not boot afterward, Chainfire wants to know about it. It means he needs to update the file. Before he can do that he relies on people leaving the new recovery image files from the firmware that is causing the issues on the CF-Auto-Root tool thread  made at the XDA-Developers website.
- Install the Samsung USB Drivers  on the Windows computer if the computer you are using does not have them already. Most problems to do with Odin and the device are due to the USB Drivers not being up to date or installed.
- Unlock the Developer Options menu and turn on the USB Debugging Mode  from the Samsung Galaxy tab before you get started with the guide so you can make changes to the Android software.
HOW TO ROOT SAMSUNG GALAXY TAB A SM-T355 RUNNING ANDROID 5.0.2
- Start by turning on the computer and logging into the administrators account so you can use the flashing tool with adequate permissions.
- Download the CF-Auto-Root  tool for the Samsung Galaxy Tab A SM-T355 running on Android 5.0.2 Lollipop software updates.
- Extract the rooting file  to the desktop of the computer and then run the Odin flashing tool that is on the desktop, so it opens.
- Boot the Samsung Galaxy Tab A SM-T355 into the download mode  and connect it to the computer with the USB cable.
- Click the AP button from Odin and browse through to the desktop and select the rooting MD5 file to upload to Odin.
- Click the Start button for the rooting to begin.
- Wait until the Odin shows a pass message inside a new green box before unplugging from the computer.
In conclusion, that is how to root Samsung Galaxy Tab A SM-T355 tablets running on the Android 5.0.2 Lollipop software updates by flashing Chainfire’s CF-Auto-Root tool—a one-click rooting tool for nearly all Samsung devices—that installs and enables the SuperSU. That’s the same SuperSU that people install from custom recovery images, and like a custom recovery image, the CF-Auto-Root tool needs to install a modified recovery to get SuperSU enabled. That happens behind the scenes after you press the Start button from the Odin flashing app.