Front Air Bag Sensor Control problems of the 2008 Cadillac SRX

Service airbag sensor light came and stays on while driving, vehicle stalls and stops. Vehicle still running but will not drive or reverse. I was on a major street at a light intersection and almost rear ended by other vehicles. Towed to a Cadillac dealer and they cannot figure out what the problem was. Still at the dealership. Three weeks prior, the same vehicle had replaced rear differential bushings, and I started experiencing accelerating problems as soon as I left the dealership. I called to complaint and was told to return the vehicle back which I did not until now. Any correlation?.