Pontiac Repair: Pretensioner Replacement

Question
QUESTION: Recently, I had the ignition replaced on a 'Recall for 2007 G5 Pontiacs.   Now,two-three weeks later,I have 'Service Air Bag' light come up on my dash.
I took it to the dealership today...they said the Pretensioner needs replacing 'under the passenger seat'.  When I looked up Pretensioner , it indicates the seat belt assembly.  I have no idea and can't find what is 'under the seat' ie. whether it's a censor or module or what.    Can you tell me what this is?  It's supposed to be replaced in 4 days ... I need your answer a.s.a.p. please and thank you!

ANSWER: Hi Carmen:

The pretensioner is the buckle part of the seat belt. pretty common issue on that car.


---------- FOLLOW-UP ----------

QUESTION: I'm confused as you and internet refers to the seat belt ( or part of it).... The dealer is trying to tell me that they have to remove the seat to replace something ' under ' it....their part cost $375.... This job will be $500+ with labour .....I looked up Pretensions and it says the whole seat belt at under $100.....   So do you know of any thing that would refer to under the seat or anything?    Thanks

Answer
the seat doesn't have to be removed to replace the pretensioner. NO you could have an issue with the passenger presence system that is a lot more expensive and requires the seat cushion being removed and calibraterd with a scan tool. that is more involved and more expensive. you need to know exactly what is wrong.