I pulled this data from the DTC B-codes and sorted it.

XK SRS/Airbag Codes    (the flash code on the airbag fault light)
   
13    Crash data memory full
16    Pass seat weight sensor CAN fault
17    Pass spatial sensor CAN fault
18    Pass airbag deactivate lamp circuit fault
19    Airbag circuit status fault – driver
21    Airbag circuit status fault – pass
22    Side Airbag circuit fault – driver
23    Side Airbag circuit fault – pass
33    Seat Belt Pretension fault – driver
34    Seat Belt Pretension fault – pass
42    Impact sensor circuit fault – front
43    Impact sensor circuit fault – driver side
44    Impact sensor circuit fault – pass side
51    seat belt switch circuit fault – driver
52    Seat belt switch circuit fault – pass
53    Airbag audible warning circuit faul
54    RCM configuration failure