Laguna Washer Systems Failure

Sounds like the pump. Could be a cable, but they're usually protected. Like a kinked garden hose – no water. Have you listened for the pump when you activate the washers? If you don't hear anything, it's likely the pump or connection.

I listened, and there's no pump sound when I activate either washer. Is it likely they share a pump? Is it easily accessible, or should I take it to a technician?

Yes, they often share a pump to save on parts. Location and access can be tricky. Without getting under the car, it's hard to say. If you are not certain, go to the workshop. It's a pain.

I'll take it to a technician. Sounds like a cable connection or relay issue. The workshop quoted 165€, which seems reasonable.