You can simulate an airbag with a 3 ohm resistor. The airbag itself very rarely fails. Either poor connection on airbag connector plug or A-pillar multiplug causing too high resistance. Or broken plastic tabs on the loom side connetor locking part not separating the shorting splices of the airbag pins and showing too low resistance.

Regarding getting P codes out of the Foxwell, I think you need to go up to the very top level from when the Foxwell powers up.

At that point, instead of selecting BMW, select OBDII, and it will tell you the OBDII codes starting with P.

You might have a situation where you have the BMW DME (etc.) codes, but no OBDII code, but just in case you're not even looking at OBDII, I'd give that a try.

I was going to mention look into the shorting bar. You said you were in there a bunch that's the most common fail point. I can't remember if the shorting bar is on the airbag or the wire side but logically on the airbag side.

About every other year that issue comes up on xoutpost and a shim made with a piece of old cc usually all it takes to fix.