The official notice
Defect
On certain vehicles, the screws that attach the control unit for the supplemental restraint system (SRS) may not have been properly tightened. As a result, the SRS control unit may not work properly and could come loose in a crash. If this happens, the seat belt pretensioner(s), airbag systems and high-voltage battery disconnect may not work correctly. Note: This problem may cause the SRS warning lamp to turn on and a "Service Urgent" message may display in the instrument cluster.
Safety Risk
A seat belt pretensioner, airbag system or high-voltage battery disconnect that does not work properly in a crash could create an increased risk of injury.
Remedy
Volvo will notify owners by mail and instruct you to take your vehicle to a dealer to inspect the mounting screws for the SRS control unit. They will be tightened, if necessary.