Airbag fault

[Iceman299]

I have a strange issue with my 206hdi. On start up it beeps and shows 'airbag fault' on the centre console display. It does this twice then it goes away. 
No warning lights on dash or faults when connected to diagnostics.
I tried a bsi reset but only left the battery disconnected for a few mins, shall i try leaving it off for longer?

Thanks in advance