FAQs > Installation> Q5: Do I need to disconnect the car battery before install
In fact, no need to disconnect the car battery, just need to power off the car (remove the car key), then the OEM car stereo system will no power at all. Disconnect the car battery might make some errors.
If you was disconnected the car battery and find some problems, such as iDrive not work, or can not access to OEM menu, etc, we recommend to install back the OEM display, and restart car, ensure that all original functions work.
After that, then install the android screen again.