One problem related to engine shut off without warning has been reported for the 2010 BMW X5. The most recently reported issues are listed below.
A known defect of an engine compartment partition/seal caused outside water to enter the engine compartment. The water drips and accumulates over the last fuel injectors, leading to an eventual short. When the short occurs, the vehicle looses all power. The engine shuts off preventing acceleration, power steering no longer functional, power brakes no longer assisted. The short occurred while driving through an intersection. The car stalled in the middle of the intersection and needed to be towed. Fortunately, traffic was minimal and other vehicles were able to slow down and drive around my vehicle, preventing a collision.