Sounds like the contact reel in the steering wheel. It is wound like a watch
spring. It really is nothing you want to do your self. The air bag is
deployed by igniting solid rocket fuel. I worked for Volvo and BMW and if
you have a safety problem thay will send a factroy service rep to the
dealership to trouble shoot the problem. If they won't contact Volvo do it
yourself. Or find another dealership.