Did a winter wheel switch and the low air pressure sensor came on, double checked psi multiple times, still perfect.

my conclusion is a tpms is faulty, problem is with our 2013 35i there is no identifier of which one it is (surprising, actually).

Am I missing something. Have owned BMW before so I understand the reset techniques, this has gone of for 3 weeks now.

How can I figure out which sensor is bad? Just take it to my local shop and having them run it on computer? It is under warranty but i bought these oem winters wheels pre-owned so I assume they won't help me unless I had the ones that came with the car (wont change back until April due to weather).

thanks!