This video covers advanced troubleshooting for PDC malfunction Alarm which is pretty common on BMWs. The video will be especially useful if you are looking to isolate which particular parking sensor is faulty. Or if its not a parking sensor issue and you need to replace the front wiring harness, this video will be of help. It also shown how to remove the front bumper to complete this task.
Overall difficulty is Moderate if you have some DIY experience.

Disclaimer: Video just documents my experience and is shared for educational purposes only. I claim no responsibility for any damage or harm.