Use a paperclip or a similar thin tool to press and hold the button for about . Release the button once the unit begins to reboot. Common Factory Settings Passcodes
If the screen is frozen or black, a hard reset is necessary:
If you are prompted for a code to enter the "Factory Settings" menu (often used for remapping steering wheel controls or changing boot logos), Grundig systems frequently use standard industry defaults: (Most common for Grundig/Android head units) 1234 123456 1617 0000 Troubleshooting Tips