hi I have a 04 f150 lariat 5.4 and has airbag code b2909 and from what I know it hasn't been in a accident and both seat belt tensioners haven't been deployed so before I go spending alot of money was wondering if any one has any idea what it could be i used a computer scanner it narrowed it down to passenger side

 

There is a fault in the belt tension sensor

 

would i be better off just replacing the whole thing under seat it's 50 for a new one