V70 Parking Aid Failure

That's plausible. The control module or radar sensors are often the cause. Have you checked the connections to the parking assist ECU and the proximity sensors themselves? A faulty rearview camera connection could also cause issues.

Could you explain where I can find the control module for the parking aid in more detail? And can I check the radar sensors myself, or do I need special tools?

The control module's location can vary, but it's often in the trunk area, behind a panel on either side. You can visually inspect the radar sensors for damage or loose connections, but thorough testing usually requires diagnostic equipment. Considering the potential complexity, visiting a workshop may be prudent.

Thanks for the advice! I visited a local workshop and it was indeed a corroded connector. The repair cost 95€. Your help was much appreciated!