a lot of times the conectors can malfunction for a bit causing it to throw up the AIRBAG LIGHT. happened to me and i cleared it via vag and it hasn't come back in about6 months now..

how to clear it in VAG:

[SELECT CONTROL MODULE]
[15-AIRBAGS]
[FAULT CODES - 02]
(make sure to copy all codes down now for future reference)
[CLEAR CODES - 05]

and now you are done!