Auto wiper fault error

My friends vehicle Peugeot 307 XT has been getting Auto wiper fault for a few months. Anyone who has encountered this situation or knows the solution before?

rain sensor or headlight wiper arm may be faulty. but if your headlight sensor works without problems, the headlight wiper arm is more heavy sonerkyl 2019-07-04 09:36:33

There is no headlight wiper in my vehicle. There is no problem on the arms. They wrote something about software or rain sensor gel on foreign sites, but I don't fully understand.