That is definitely screenwash warning.

 

You would know if it was the pump, as when you pull the stalk to squirt the screen, there would be no noise from the pump.  Usually sounds like a "humming" noise if you squirt the screen.

 

Are you losing washer fluid? Test by filling up, marking a line, and seeing if the fluid disappears over a day or so.

Just yesterday I've messed around with the same thing, it leaked washer fluid. Pump works, but it seems like the fitting where the pump inlet meets the plastic tank is kinda old and it leaked washer fluid. My solution was to disassemble it, clean it up, dry it well and then put some elastic glue on it and tie it down firmly with some zip ties. Hopefully it's dry now, will fill it up and test it soon, fingers crossed it worked!