Two problems related to air bag have been reported for the 2011 Chevrolet Volt. The most recently reported issues are listed below.
Since the spring of 2020, "service air bag" warning comes on intermittently, related to passenger seat airbag. Warning generally comes on at startup, if it appears. No fluids have been spilled on the seat, and no visible damage to the seat. I am the second owner, purchased from friend, car has always been garaged and serviced regularly. Online search suggests that other owners have same issue, and that diagnosis and repair can be $500 to $1000. I have not had a Chevrolet dealer diagnose this issue since it is intermittent. Current market value of vehicle (55k miles, otherwise excellent condition, a great car to drive) makes cost of repair difficult to justify, especially if it could happen again without warning.
'service airbag' chime and light coming on, routinely, even with or with anybody in the passenger seat. I have not taken the car to a dealer yet since I have been reading forum input about this issue and seeing huge cost to repair. Car has only 81k miles and has never been flooded or had water on the seat(passenger).