I am researching the same exact thing for my 2012 T&C. I
recently replaced my front brakes. While trying to put a jack
stand under the van, the van rolled back and fell on the
jack stand knocking a small hole in the transmission end
cover. I patched it since that is a dealer only item but the
patch didn’t hold and it leaked transmission fluid. I think
some ATF got onto the wheel speed sensor or something. I
test drove it today after I repaired the cover and that’s
when the airbag light came on (along with a single
annoying bell sound) for about 20 seconds, go off for about
a minute, then come back on. It stayed off for the last 5
minutes of my drive so maybe if it were ATF or debris on
the wheel speed sensor it came off. I’ll know more
tomorrow.