How do you restart the parking sensor on citroen xsara Picasso?

To restart the parking sensor on a Citroën Xsara Picasso, first, turn off the ignition and remove the key from the ignition switch. Wait for about 10 seconds, then reinsert the key and turn the ignition back on. If the sensors still don't function properly, check for any obstructions or debris on the sensors themselves, and ensure the wiring is intact. If issues persist, consult a professional for further diagnosis.