NHTSA Complaint #11433454 — 2012 BMW 328I

While driving car at speeds <30 mph, on hitting a minor bump on the road, car engine suddenly stopped with a "Drivetrain malfunction" error. The car lost all power within a few seconds, including power steering. The instrument cluster was off except for error message. Transmission shifted to Neutral automatically which I believe is by design. On somehow maneuvering in traffic and coasting to a stop, and waiting a minute and pressing the ignition start button, car powered on immediately and was driveable. The same incident repeated within 30 miles of driving. A local authorized service center found no existing problems although there are several error messages logged by the on board computer. The safety is severely compromised and the car can be easily rear-ended since hazard light signals also failed. The vehicle has otherwise been regularly maintained at authorized service centers.