If none work, contact Grundig support or check your user manual.

. If you are prompted for a PIN, it is most often the Bluetooth pairing code or a generic service code. Common Reset Methods Physical Reset Button

to confirm. The unit will reboot, which may take 5–10 minutes. Car Tech Studio Troubleshooting & Features Wired Requirement

If your unit is frozen or you need to clear all data, try these steps as recommended by technical support resources like JustAnswer Soft Reset (The Paperclip Method):

By performing a factory reset, you can:

Continue holding the button until the text-based Android Recovery Menu appears on the screen.

Insert a straightened paperclip, toothpick, or SIM ejector tool into the hole. Press down gently until you feel a button click.