Originally Posted by coolbecauseiam
Could be incorrect movement of vehicle. Causing a safety interlock procedure.
Check your owners manual on safely moving the vehicle; engaging/disengaging park, park brake, transmission lock.
Did you have your seat belt on? The vehicle may have engaged park brake automatically. Due to users causing uncontrolled rollback there are safety interlocks built into new vehicles to prevent people causing damage and/or harm.
Thanks for your theory and we will check out your suggestion. However, the car was barely moving and only moved a few feet. Didn't have a seat belt on and we do know NOT to move the transmission out of neutral if the car is moving, but come to a full stop and depress the brake pedal before moving the trans into gear. We are still concerned as to what caused the bang as when we tried the same procedure a second time, the brakes just worked as expected without the bang. Sounds like too much computer control is possible and I wonder just how safe allowing a computer to take control really is.