If your steering wheel control is not working, please use this guide to update the firmware.
Please download the file "Tangdu.bin" onto your computer, make sure the name stay as "Tangdu.bin". Move the file to a flash drive and do not put it in any folder.
Plug in flash drive to the unit, go to setting > System Info > MCU update > MCU update > Tangdu update > You should see a progress bar appear and wait for it to complete if the previous setup is correct. The unit will reboot after progress bar complete.