XC70 Wiper Failure

Sounds like a dodgy connection. Have you checked the wiring and plugs around the steering column? The wiper switch is there. Could be a loose wire.

Thanks! I'll check the steering column. Can the rain sensor cause wipers to fail completely, or is that a separate issue?

The rain sensor could be involved, but if the wipers are totally dead and you've got an error code, a wiring issue or the switch itself is more likely. If checking those connections doesn't help I would take it to a workshop.

It was a defective plug connection, as suspected. Workshop repaired it for 95€.