I'm getting the pieces for missing front airbag sensors (the radiator support was replaced) for an Audi A3 2011 8P.
My usual goto spot for VAG part diagrams here shows a diagram with one sensor - part number 8J0959651. However running VCDS to look at the airbag codes, VCDS reports an open circuit error for the passenger-side and the drivers-side. Looking at the radiator support, there is a mounting spot for a sensor on each side. I suspect the wiring harness was damaged on one side so there's no evident plug (at least to me). The passenger side has a yellow plug that seems to be the correct connector.
So I want to determine whether I need one or two of these sensors. I don't plan on touching anything airbag related (aware of the dangers). I just want to give the right parts to an knowledegable automotive electrician who can do the required repairs.