The wiper control module is the black plastic cover on the wiper motor. My guess is you need a new one. GM should still have them available. They may also be available aftermarket. It's a fairly easy fix.
Easy yes but expect to pay almost 100 bucks for a new one I need a new one too I called Hawks they have one for 45 but when i asked if it was delay the guy said " it should be " and that was not good enough for me so I'm stuck with no delay or washer for now till I have an extra 100 .good luck