Airbag defective sensor in Citroen C2

Hello everyone, I am new in this forum and I wanted to ask you a not very difficult question.
I have recently bought a Citroen C2 of the year 2005, all phenomenal until the other day that I was very very momentarily lit by the chivato of defect in the airbag, but not even 10 sec when it went out, this is often happening to me often.
I have been looking online, which is due to the clemas under the front seats, but I have not had the opportunity to look at them at the time it has been.
I ask you advice, if that is that or something else.

Thank you so much